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DICTIONARY OF CHEMISTRY 
 
DICTIONARY  OF CHEMISTRY
CONTAINING
               THE PRINCIPLES
                        AND

      MODERN THEORIES OF THE SCIENCE.

                 WITH ITS APPLICATION TO

THE ARTS, MANUFACTURES,  AND MEDICINE

      For the use of Seminaries of Learning and Private Students.
TRANSLATED FROM
Lom\<$, V id this
-■E DICTIONNAIRE DE CHIMIE, APPROUVE PAR VAUQUELIN.'

                • l  f* - -- >.,     -^
    INCLUDING THE 3tQ^»^Ttf;r IfT;Bt|K OAIERIES AND DOCTRINES
              ^\,  OF THE SCIENCE,



           WITH ADDITfDNS AND  NOTES,
        BY MRS. ALMIRA H. LINCOLN,
     vice pbincipal of troy female seminary, author of
            "familiar lectures on botany."
       NEW  YORK:
G. & C. & H. CARVILL,
            1830. 

sol thern District of New York, ss.
  BE it remembered, That on the twenty-second day of June, A. D. Id30, in tlif
fifty-fourth year of the Independence of the United States of America, G. & ('
& H. Carvill, of the said District, have deposited in this office the title of a book,
the right whereof they claim as proprietors, in the words following, to wit:
  " Dictionary of Chemistry, containing the principles and modern theories ol
the science, with its application to the  arts, manufactures, and medicine.  For
the use of seminaries of learning and private students.  Translated from ' Lp
Dictionnaire de Chimie, approuve par  Vauquelin.'  Including the most recent
discoveries and doctrines of  the science.  With additions and notes, by Mrs.
Almira H. Lincoln, Vice Principal of Troy Female Seminary, author of' Fa-
miliar Lectures on Botany.' "
  In conformity to the act of Congress of the United States, entitled " An act foi
the encouragement of learning,  by securing the copies of maps, charts,  and
hooks, to  the authors  and proprietors of such copies, during the times therein
mentioned;" and also to an act, entitled " An act, supplementary to an act, en-
titled An act for the encouragement  of learning, by securing the copies of maps.,
charts, and books, to the authors and  proprietors of  such  copies, during thu
times therein mentioned, and extending the benefits thereof  to the  arts of dc-.'
signing, engraving, and etching historical and other prints."
                                     FREDERICK J. BETTS,
                              Clerk of the Southern District ©f New York-,
SKight & Robinson, printers, No. 26 William street. 
        Copy of a letter of Professor Eaton to Professor Sillima'n<

                  To Professor Silliman.
   Dear Sir,
             The Messrs. Carvill will send for your examina-
lion the printed sheets of the Dictionary of Chemistry now in
the course of publication.  It may be proper that I should tell
you how this work came to be translated from the French by
Mrs. Lincoln.
   Being a teacher of experimental  chemistry, according to
the course of my little text book, I found that a dictionary would
be very important. Ure is too  large.   It is rather the whole
science given alphabetically.   I had  nearly come to the con-
elusion to undertake the labour of preparing one which should
be intermediate  between an alphabetical exposition of the
whole  science, and  a mere  definition  of words ; and which
should be brought down  to your "posting up" of the science
in the system you have just published.   At that moment I re^
ceived a French copy of this work.   I examined it with  parti-
cular care, and used it continually for six months.  It appear-
ed to me to be every thing which the  pupils of great and small
teachers, like you and myself, require.   As the Troy Female
Seminary  need a similar work,  I prevailed  on Mrs.  Lincoln
to undertake  the translation.   Being; herself a  teacher of che-
mistry, a  good French scholar, and having a learned native
Frenchman for an assistant tencher,  I knew she could execute
it  better than almost any one.  I  have now examined  the
printed translation, and do not hesitate to say  it is  well trans-
lated, and that the mechanical part by Messrs. Carvill is well
wecuted,
                   Yours, most respectfully,
                                   AMOS EATON,
                          Senior Professor in the Rensselaer School
  TroYjN. y , June 13, 1830. 
Copy of a letter from Benjamin Silliman, M. D., Professor of Ctaemistry, PJiai
    macy, Mineralogy, and Geology, in Yale College, New Haven, Conn.

  Having examined a sufficient number of articles to enable
me to form a judgment of the value  of the Dictionary of Che-
mistry, translated from the French by Mrs. AlmiraH. Lincoln,
and published by Messrs. G.  & C. & H.  Carvill, I have no he-
sitation in saying that it appears to me  to  be a learned,  judi-
cious, and able performance.
  I have  never seen the original, but the translation carries
with it internal marks of accuracy;  and I am impressed witli
the belief, that this Dictionary will answer a very valuable pur-
pose both to learners and  teachers  of the science in this
country.
                                         B. SILLIMAN
  Yale College, June 22,1830. 
TRANSLATORS  PREFACE.
  The origin of this volume may be learned from the
foregoing letters ; should it be destined to as favourable
a reception as has been given by the public to the " Fa-
miliar Lectures on Botany," the translator will consider
herself as repaid for months of severe application, in
which, relinquishing  the  pleasures  of"  society,  and
abridging the hours allotted to repose, she devoted all
her leisure to the accomplishment of this object.  She
hopes to  disarm criticism by an humble acknowledg-
ment of imperfections ; and solicits from the friends of
science correction of any material  errors that may be
noticed,  and indulgence  for the  inadvertent  use  of
French idioms, or an occasional want of perspicuity.
Through care to avoid ambiguity the very fault  itself
may sometimes have been committed.
   The style of a dictionary must at  best be dry and
sententious;  this is not proposed as a reading book, but
chiefly for reference, as will be seen by recurring to the
introduction of the compilers, which  explains the use
and importance of  a chemical dictionary.  The  com-
pilers  of  the original  work are  MM. Brismontier, Le
Coq and Boisduval;  these gentlemen, impressed with
the importance  of such  an undertaking,  united their 
Via
translator's preface.
  labours,  selecting  from the best  French and English
  authors up  to the year 1826, which was the  date oi
  their publication : their work having been submitted to
  the great chemist, Vauquelin, appeared under the sane
  lion of his illustrious name.
    The translator has made additions  from Ure, Web
  ster, Green,  Journal of Science, Silliman's Chemistry,
  and some of the latest French writers.   The original
  work, in many cases,  has been considerably abridged.
  particularly in the long processes for the manufacture of
 gunpowder, glass, saltpetre, &c.   The physician may
 notice a deficiency of some articles connected with ani
 mal  chemistry, but will readily comprehend the  pro
 priety of these omissions.
   The History of Chemistry,  and Sketch of Ele
 mentary Chemistry are added to supply a deficiency
 in the books  used in schools ; these parts are designed
 to be read  by pupils with reference to public examina-
 tions.  The  History of a Science, or in other words.
 of the progress of the  human mind in relation to that
 science, is always interesting, and furnishes  hints  for
 future improvement.    General  views  of a science-
 enable the student to comprehend the beauty and regiv
 larity of the whole as a system;  it is indeed necessary in
 commencing, to proceed by the slow and sure method
 of learning single facts, and of deducing from these facts,
 general principles;  but in  course of time an opposite
 process becomes necessary;  we need to pause in order
 to examine the  ground  already passed ; and standing
as it were upon  an eminence, to comprehend under one
general view, the facts which establish  principles, and
the  principles  which constitute the science. 
translator's preface.
IA
    in this institution, according to the excellent method
  introduced  by Professor Eaton into the Rensselaer
  School, each pupil in Chemistry, is required to prepare
 a lecture with suitable experiments for public examina-
 tion ; in addition to this exercise the History of Che
^jnistry, and Sketch of Elementary Chemistry of this
  volume will furnish proper subjects for a general exami
  nation of the class.   To some of the teachers and pu
  pils of the Seminary  the translator would offer hei
  thanks for their kind assistance in transcribing the fol
  lowing pages for the press.
    The publishers and translator consider themselves a>
  fortunate in having secured for the work while in press.
  the care of Dr. Sidney  Doane, of New York, a gradu
  ate of Harvard University, who having recently passed
 two years in Europe, and attended the chemical lec-
  tures of the savans of  Paris, was highly qualified for
  the trust.   While the translator would do justice to Dr.
  Doane's faithfulness and ability, she would not be under
  stood as laying upon him any responsibility for the cor-
 rectness of the work, either with respect to facts or style.
  She would again request indulgence for any occasional
  errors, and remind the public that these pages have been
 written amidst the  interruptions  and duties  incident
 to her connection with this  institution.  To use the
 words of an elegant scholar and distinguished  chemist,
 "life is fast flying away, while in the hope of discharging
  more perfectly our  obligations to  our fellow-men, we
  wait in vain for continued seasons of leisure and repose,
  in which  we may refresh and brighten our faculties,
  and perfect our knowledge. After we are once  engaged
  in the full career of duty, such seasons never come : 
\
translator's preface.
 our powers and our time are placed inin cessant requis.i
 tion:  there  is no discharge in  our  warfare;  and w<
 must fight our battles, not in the circumstances and po
 sition which we would have chosen, but in those  forced
 upon us by imperious necessity."
  Troy Female Seminary, June 17, 1830.

  N. B. In the French dictionary,  temperature is expressed
by degrees of the centigrade therometer, 100 of which equal
212<> of Fahrenheit; in the translation these have been con-
verted into degrees  of Fahrenheit;  this is done by multiply-
ing the centigrade  number by 9, dividing the product by 5,
and adding 32 to the quotient;  for as 5 : 9 : ; 100 ; 212—3? 
HISTORY  OF CHEMISTRY.
  The study of nature, as exhibited in the material ob^
jects which compose the globe, and exist upon or near its
surface, is called Physics, while the study of the mental
phenomena, in contradistinction, is called Metaphysics.
  Physics,  or  the  study of nature,  includes  Natural
Philosophy, which acquaints  us with  the  general  pro-
perties and mechanical laws of bodies,  the physical laws
of attraction, light,  and  electricity ; it  is founded on ob-
servation and experiment, and  derives  important assist.
ance from mathematical science.
  Mathematical Science is founded on intuitive or self-
evident  truths, and embraces the  relations of magnitude
and number.  On this science  depends the measuring of
heights and distances, the computation of quantity, the
principles of perspective drawing, navigation,  surveying,
and astronomy.
  Astronomy teaches  the  motions, dimensions, and dis-
tances of the  heavenly bodies; it is superior to all  the
other natural sciences, in  the vastness and sublimity of
its objects ;  its practical utility is very  great in directing
the navigator to pursue his way through the trackless
ocean.   The superstitious  fears with which some of the
phenomena of nature anciently  inspired the ignorant, are 
  vu             history of chemistry.
  dissipated before the light of astronomical science ;  an
  eclipse ceases to be viewed as an intimation of the wrath
  of an offended Deity, when its  physical cause is calcu-
  lated and explained.
    Natural History considers the external appearance
  of natural objects ;  the term history, which literally sig.
  nifies a description of actual appearances, not being con-
  fined to the same meaning as when applied to the history
  of nations, or civil history, which signifies a relation of
  past events.
    The divisions of natural  history are zoology,  botanv.
  and mineralogy.
   Zoology, which includes the whole  animal kingdom,
 from the human species to the smallest  animalcules, has
 many subdivisions ;  as ornithology or the study of birds,
 ichthiology of  fishes, entomology of insects,  conchology of
 shells, &c.
   Botany investigates the vegetable tribes, including all
 organic substances not comprehended under the  animal
 kingdom.   The oak of the forest, the rose and lily of the
 garden, the grass of the  meadow, the moss that grows
 upon the rock, and the lichen which  appears on decayed
 wood and the barks of old trees, are subjects of this study.
 Botany has not unaptly been termed « the poetry of na-
 tural history."
  Mineralogy is the science which  arranges  the inor-
ganic substances of the globe, including not only earths.
metals, salts, and combustibles, but water and atmospheric
air; all material substances on the globe not embraced 
               history of chemistry.             xiii
in the other two departments of natural history, are the
objects of this science.  Although organic substances are
in general more interesting than minerals,  yet the latter
present to the investigating mind never failing objects of
interest and admiration.  The subject of crystallization
offers many wonderful phenomena ;  and there seems no
less a mysterious agency operating in the-atoms~©#4j©dies,
and leading them all to arrange themselves in their cha-
racteristic forms of crystals as cubes, prisms, octagons,
&c, than in the wonderful  organization  of plants and
animals.
  Geology, a branch of mineralogy,  includes a know-
ledge of  minerals as they exist in large masses, forming
rocks,  mountains,  &c.   It investigates the structure of
the globe, the nature of the changes it has  undergone,
and by the  aid of experience prophesies future  revolu-
tions.  It is an important study when viewed either in re-
lation to the grand objects with which it is conversant, or
in its ennobling effect upon the minds of those who pursue
its bold investigations.
  Chesiistry takes a wider range than any other depart-
ment of physical  science ; in the mineral kingdom it pe-
netrates the hardest materials, and inquires into the nature
of their elementary  constituents.  In the vegetable sub-
stances, chemistry with scrutinizing  glance detects their
medicinal and  nutritious  qualities;  do  these  require
to be  separated from their  various combinations? this
almost magic art can disentangle and set them free.  In
the animal kingdom,  chemistry  performs a high and so- 
 Xiv            HISTORY OF CHEMISTRY.
 lemn office, teaching proud man himself, that his  o\v - >
 material frame,  beautiful in its  aspect and  noble in its
 bearing, is in  truth but a compound of a few simple ele-
 ments,  which as they have previously existed in other
 combinations, will again be dissipated to become parts of
 the worm that " feeds sweetly" upon the  decaying body,
 and the noisome weed or lowly plant that springs from the
 soil which covers his earthly remains.
   The term chemistry is by some supposed to be derived
 either from the Greek word  kemia, or the Arabian chamia,
 which signify to  burn ; and that this science at first sig-
 nified the examining of substances  by fire.   By others,
 the word chemistry is supposed to have been  used  by the
 Egyptians in a sense equivalent to the present meaning
 of the term natural philosophy.   Science among the  Egyp-
 tians, was for  a  long time  confined to the wise men, or
 magi, who carefully concealed their  knowledge from the
 people; Plutarch supposes  that  the study of nature, for
 this reason, was called chemistry, which word, in his opi-
 nion, signified the secret science.   Whatever  might have
 been the degree of knowledge of nature possessed by the
 Egyptians, they were  probably acquainted with the most
 important  facts on which the science of chemistry  i?
 founded.
  The Israelites gained from the Egyptians some  know-
 ledge of the art of working metals, and of dyeing red, blue,
 purple, and scarlet. The Phoenicians  are supposed to have
 understood the manufacture of glass,  perfumes, and imita-
tions of precious stones.   This  knowledge was succes-
 sively communicated to the Carthaginians and Greeks, 
               HISTORY OF CHEMISTRY.             XV
and by them to the Romans ; the  two latter people seem
however to have possessed  but a very limited knowledge
of any chemical operations, or any branch of analytical
science.   Plato seemed sensible  of this when he makes
an Egyptian priest say to Solon, " You Greeks will be al-
ways children, for you  have neither the antiquity of know-
ledge, nor the knowledge of antiquity."   The religious be-
lief of the Greeks and  Romans may afford some excuse
for their  ignorance of  nature ; who among them would
have dared to take water from a fountain or a river, and
decompose it by fire ? they would have  considered it  as
an act of  sacrilege against the Naiad, or the protecting
divinity of the stream ; the grand priest would  have ex-
claimed against the  impious wretch, and  the people in
their indignation would have torn  him to pieces.
  Although the Egyptians were idolaters, yet less imagi-
nation was mingled with their religious belief, and free from
many of the superstitions which kept other nations in in-
tellectual  bondage, they dared to  look into the secrets of
nature.   Pliny the elder places the Egyptians as first in
the knowledge of the sciences.   Democritus of Thrace,
who flourished 500 B. C, travelled into Chaldea, Persia,
and Egypt; in the last country he gained a knowledge of
chemistry that appeared to Pliny almost super-human;
and yet this classical and venerable land has transmitted
to us scarce a vestige of any discoveries !  But we cease
to be surprised at this,  when we reflect that the library of
Alexandria, which contained their  treasures of know-
ledge,  was  successively destroyed by the victorious Ro-
mans and Mahometans. 
 XVI            HISi'ORY OF CHEMISTRY/.
   Science, driven from Egypt, Greece, and Rome, in the
 4th century took  refuge  in  Arabia,  and chemistry ap-
 peared under the name of Alchemy.
   The alchemists imagined that gold existed in all metals.
 and it was their great object  to ascertain  the manner in
 which it  might  be separated  from its combinations  and
 obtained  pure;  they expected to  find  some substance
 which would enable them to perform this great operation ;
 this imaginary substance,  which some pretended to have
 discovered, was called the philosopher's  stone.  Those
 who studied alchemy pretended to great socrecy, affirm-
 ing that some heavy calamity would  fali  upon any one
 who should reveal the principles of the science ; keeping
 themselves separate from the world, they invented myste-
 rious characters by which  the initiated could hold corres-
 pondence without danger of discovery.
  Among  the alchemists,  notwithstanding the  folly of
 their pursuit,  and  the  baseness of their deceptions, we
 find  the names  of  a few  distinguished for talents and
learning.   Albert the Great, a German who lived in the
 12th century, wrote  a work upon alchemy, in which  he
described  the chemical processes  then in  use.   His
treatise on metals was written with clearness, and showed
a mind familiar with many of the  phenomena of nature.
His countrymen, astonished at the  extent of his  know-^
ledge, accused him of magic,  and  threw  him into prison.
His pupil, Thomas  Aquinius, wrote upon  alchemy, and
for the first time the word amalgam was introduced into
chemistry.   In his writings astrology and alchemy were
united. 
                HISTORY OF CHEMISTRY.            XVii
   In  England, cotemporary with Albert the Great, was
Roger Bacon, the most  enlightened and judicious of all
the alchemists.   In his treatise  " De mirabili potestate
Artis et Natures" (the wonderful power of art and nature,)
he protested against the  foolish belief in magic, charms,
and necromancy ; he asserted that superstition tyrannized
over the human mind through  ignorance of natural phe-
nomena.  He was acquainted with the camera obscura,
telescope, and the use of gunpowder.  Notwithstanding
he carefully concealed  his labours, he was accused  of
magic and imprisoned.   Raymond Bully treated of the
preparation of acids and phosphorus.
   About the middle of the  12th century, Arnold de Villa
Nova, a physician consulted by kings and popes, directed
alcohol and  the oil of turpentine to be used in medicinal
preparations.  John and  Isaac Holland wrote several
treatises on  chemistry, with plates representing the appa-
ratus  which  they used.   They made  experiments  upon
human blood, which have  aided the most recent disco-
veries.   They invented the art of enamelling and colour-
ing glass and precious stones.
   Basil Valentine, a German monk, taught  that all sub-
stances were composed of salt, sulphur, and mercury; he
was  the  first who applied  chemistry to medicine.  The
most important of his works was called Currus Triumphalis
Antimonii, (triumphal chariot of antimony ;)  in this he
gave such an account of his experiments with this metal
as excited an interest among  all  the physicians of  Eu-
rope.
                          2* 
 ^Vlii           HISTORY OF CHEMISTRY.
   An opinion had long prevailed  among the alchemisb
 that a medicine might  be discovered which  should be a
 universal cure or panacea* for all diseases; some asserted
 that this could be found in the philosopher's  stone, which
 not only converted metals into gold, but among other ex-
 traordinary  virtues,  possessed the power of rendering
 man immortal upon earth.
   Of all the alchemists, none  appear to have  pretended
 to so many  discoveries  as  Paracelsus, a native of Swit-
 zerland, born in 1493.   He confidently boasted that  he
 was in  possession of an elixir which would render him
 immortal; but he died in the  prime of life, leaving his
 followers overwhelmed with shame  and  dismay.  The
 last of the alchemists was Van Helmont, who boasted of
 being in possession of  the universal remedy  to which  he
 gave the name of alkahest.
   The  alchemistical system crumbling into ruins, che-
 mistry,  like  the fabled Phoenix, arose from  its  ashes.
 Beccher, a  professor of medicine  in  Germany,  taught
that  the earth was not  a simple element, but a combina-
tion of elements ; he attempted to establish chemistry on
its true  basis, that of analysis; his experiments were of
great use to succeeding chemists.
   StahJ, the pupil of Beccher, remodelled and simplified
the theory of his  predecessors, attempted to  explain the
process  of combustion, and to reduce the  phenomena of
chemistry under a certain number of heads.  His  theory
of combustion supposed  that a certain substance which
he called phlogiston formed a part  of all  combustible
   * Tins term is derived from two Greek words, signifying to cure all. 
               HISTORY OF CHEMISTRY.             XIX
bodies, and that its  separation constituted fire.  On ac-
count of the boldness of his investigations, he was called
the sublime Stahl.   He is the first chemist who appeared
to have any clear ideas of chemical affinity;  he even sug-
gested the theory of double elective attraction.
   At  this period many learned men were engaged  in
chemical pursuits, and the  science  Was enriched  by the
discoveries of Boyle, Agricola, Glauber, Kunckel, Liba-
vius, Bohnius, Lemery, and others.
   Boerhaave, an accomplished philosopher and celebrated
physician, published  a  system of  chemistry in  1732,
which contained a more ample collection of chemical ex-
periments, and more clear and  precise directions  for re-
peating them, than  any previously offered  to the world.
He gave an account of vegetable analyses, more  simple
and scientific than any which had before appeared.
   Notwithstanding  all  these  improvements, chemistry
was yet in  a very imperfect state ;  some  of the  absurd
notions of the  alchemists still remained, and loose and
unsatisfactory reasonings, founded  on vague analogies,
were employed.  It was not  for  a common mind  to
attempt to remove the shackles of prejudice which ages
had been riveting  upon the human intellect.   At this
time appeared Bergmann, a man gifted with a quick and
discriminating genius, a moral courage that could look
above " the world's dread laugh," and a devoted  enthu-
siasm for the science  of chemistry.
   With a true analytical method he scrutinized  nature,
 with  a view to ascertain her  laws of aggregation ;  he
arranged the well known tables of elective attraction, and 
 \X             HISTORY OF CHEMISTRY.
 published  many  important  experiments  upon  volcanic
 products.  The clearness of his conceptions, the accu-
 racy of his observations, and the methodical arrangement
 which he introduced into  the science of chemistry, en-
 title Bergmann to a rank among its greatest benefactors.
 \ native of the same country, and cotemporary  with the
 great Linnaeus, it was his high  destiny to labour  with
 almost  equal success in the cause of natural science;
 while Linnaeus  was investigating  the external  forms of
 matter, with a view to the  systematic arrangement of the
 animal, vegetable, and mineral kingdoms, Bergmann was
 analyzing and arranging the elements of which they are
 composed.   With the frankness  and generosity  which
 marks a noble  mind,  he sent to Linnaeus an account of
 his experiments and  observations ;  the latter, equally
 generous, forwarded Bergmann's communications to the
 academy of Stockholm with this inscription, " Vidi et Ob-
 slupui," (I have seen and am amazed.)
   Scheele, the pupil and friend of Bergmann, enriched
 chemistry with new and  important  facts;  he  died in
 1786, two years after the  death of his predecessor; his
name is commemorated in the name of a compound of
 copper and arsenic, (arsenite of copper,) called Scheele's
green.   By a late  distinguished chemist*  he  has been
 called the Newton of chemistry.
   Soon after the death  of Bergmann and Scheele, a series.
of splendid discoveries marked the advancement of che-
mical science in Great  Britain.  Dr. Black discovered
* Thomson. 
                HISTORY OF CHEMISTRY-             XXI
 the existence of latent caloric, and that limestone  is a
 compound of lime and  an aerial fluid, which he called
 fixed air, now called carbonic  acid gas.  This discovery
 gave rise  to pneumatic chemistry, or that  branch of the
 science which relates to gases.
   Mr. Cavendish soon after this discovered hydrogen gas.
 In 1770  Dr. Priestly commenced  a  series of pneumatic
 discoveries ;  he observed that by heating certain metals
 a kind of air was obtained, much purer than  the atmo-
 sphere, and in which  combustible  substances burnt  with
 great brilliancy; it is scarcely necessary to say that this
 was oxygen gus.
  While the science of  chemistry was receiving these
important acquisitions  in one  part of  Europe, Lavoisier
in France bad  already commenced  his  brilliant career,
and opened to his countrymen  that pathway to scientific
distinction, which  so many have since pursued with al-
most unrivalled success.   Lavoisier found that the recent
 discoveries with respect to gases could not be reconciled
 with the  phlogistic theory of  combustion ;  and,  after
years of patient and laborious  investigation, he published
the grand  theory which considered oxygen  as  the  sup.
porter of combustion.   This theory at first met with ge-
neral oppos<<ion, but  gradually gained supporters, until
Cavendish,  Berthollet,  Black, Morveau, Fourcroy,  and
Kirwan,  (the latter of whom  had strongly opposed it,)
were found among its disciples.
  In 1787, Lavoisier, Fourcroy, Berthollet, and Guyton
 de Morveau, were appointed by the French  academy to
 [leeide upon a  nomenclature  of chemistry ;  with great 
xxii
HISTORY OF CHEMISTRY.
 care and research they formed that  which is  now the
 almost universal language of the science.
   Great Britain may boast of many distinguished modern
 chemists ; of Davy, the  powerful  advocate of the chlori-
 dic theory, and the inventor of the safety lamp ;  Murray,
 Brande, and Thomson, with many others, whose labours
 have enlightened  the present age, and  whose works will
 render  their names familiar to  succeeding generations.
   On the continent,  Berzelius, Vauquelin, Berthollet,
 Gay-Lussac,  Thenard,   Dumas,  Dulong,  Pelletier,  and
 others,  have carried their researches and  analyses to a
 degree  of accuracy and clearness hitherto unrivalled.
   The  year 1829  is memorable for the  loss sustained by
 science, in the death of two of her most distinguished vo-
 taries ;  but long will the  halo of glory encircle the vene-
 rated names of Vauquelin* and Davy.
   In  America,  Franklin, fearlessly encountering  the
lightning from heaven, proved its identity  with electri-
city, and taught mankind to guard against this awful agent
of destruction.  Hare, Silliman,t Eaton, with other vete-
rans in  the science, and  less experienced  chemists,  are
interrogating  nature with a  brighter  prospect of disco-
very than that which encouraged the efforts of their prede-
cessors  ; for as the field of discovery and improvement is
infinite, in  proportion as facilities for them are multiplied.

 * It was under the auspices of this great chemist that the original of the Che-
mical Dictionary was published.
 t Perhaps no chemical work has ever been published, which exhibits objects
of the science in so clear a light as  Professor Silliman's late volume of chemis-
try; the anxious inquiries for his promised second volume, prove that the
work is suitably appreciated by the public. 
                HISTORY OF CHEMISTRY.           XXlli
 so are the motives for exertion.  As proper would it have
 been, at the period when earth, air, fire, and water  were
 considered as the four elements of nature, for an investi-
 gating  mind to have rested in this  belief, as for such a
 mind at this  day to suppose that we have  arrived at the
 maximum of human knowledge, or have already learned
 as  much of the  properties of matter  as  its Almighty
 Creator wills that he should know.
  From the nature of chemical experiments, which in
 most cases require either firmness of nerve, unshrinking
 courage, or physical strength, and  sometimes all these
 qualities combined,  woman may not aspire  to add to the
 stock of chemical  science  discoveries of her own ; but
 gifted with the intellectual power to  trace the relation of
 cause and effect, and comprehend the wonderful proper-
 ties of matter which science reveals, she may dare to raise
 the  curtain which conceals the operations of nature, and
 entering her laboratory, behold the grand experiments
 which are there exhibited ;  nor should it be considered a
 small privilege that she is permitted  to share in the  sub-
 lime discoveries of science, and to feast on the banquet, of
 knowledge prepared by others.
  Is it not more noble for an immortal soul thus to employ
itself in learning the  second causes  by which the Deity
operates in the material world, than to waste the precious
hours of existence  in  dreaming over  sickly  works of
fancy ?   Can the  admirers of sublimity and beauty find
none  in the study of nature;  or can the  lovers  of the
 marvellous find no wonders in her operations ? 
XXIV           HISTORY OF CHEMISTRY.
  There is in chemistry poetry to satisfy the most extra-
vagant fancy, and in the sublime truths of the science are
mysteries far surpassing the boldest conceptions of human
genius. 
INTRODUCTION
  In order to facilitate the  study  of chemistry, we
here, comprised within a small compass,  present  a
complete history of  the  science.   It  may, at first
view, seem impossible that we should, in so small a
work, have treated of all the important subjects  which
have filled  so  many voluminous  treatises on this sci-
ence; or rather, it may be asked, if this abridgment is
not made at the sacrifice  of  that perspicuity which  is
necessary to a proper understanding  of the subject ?
It is for our work to answer this;  we will, however,
say in anticipation, that we do  not  fear the reproach
of having omitted any thing  essential;  we may even
be accused of having, with the modern names,  been
too  particular to  bring from comparative  oblivion,
names employed by ancient chemists.   We have en-
deavoured to exhibit theories in the clearest possible
light, and have referred the reader  to more extensive
works, when the importance of the subject has seemed
                        3 
XXVI
INTRODUCTION.
to demand further  investigation  than our  limits al-
lowed.
  We do not however suppose  that our Dictionary
alone will be sufficient to  those who would  penetrate
the depths  of chemical science 'f no science, nor  lan-
guage, can be  acquired  by the  aid of a dictionary
alone; the alphabetical order of such a work is op-
posed to methodical investigation; but a dictionary
seems indispensable  as an appendage  to  elementary
works, facilitating the progress of the  pupil, by ena-
bling him, at one glance,  to see the properties of the
substance whose history he is studying.
  With respect to such persons as do not wish the la-
bour  of close and  methodical investigation, portable
scientific dictionaries must be to them a vade mecum ;
to them it is not an object to arrive by degrees to the
knowledge of a particular substance or combination ;
they wish to see at one view a complete history of its
essential  properties.   With elementary works this  end
cannot be obtained ; the most methodical, transport a
reader, who searches for  the history of any one sub-
stance, to many different parts of the work :  suppose,
for instance, a metal  treated of; its extraction, its phy-
sical and chemical properties, its various combinations,
the preparations of which  it makes a part,  all these
circumstances become subjects of different sections,
and the reader must  compass the whole work in order 
INTRODUCTION.
XXV11
to obtain correct and precise ideas of this one sub-
stance.
  We believe the wants of the public truly justify our
labours.   We have no fears, in the present enlightened
age, when the taste for science seems so  extensively
diffused through  all classes of society, that our efforts
will  fail  of being duly  appreciated.  The  love  for
science which  the present age so peculiarly exhibits,
ought to be encouraged.   What more noble  use can
man make of his intelligence, than to apply it to the
the knowledge of the objects which surround him r
Chemistry may  well  be  considered as  pre-eminent
among  the useful  sciences;  divested  of the errors
which, thirty years  since, rendered the science so in-
tricate and  unsatisfactory, it  is now open to the  re-
searches of all.   Nature, if we may so speak, has no
longer her secrets; chemistry has discovered the phe-
nomena which operate in her  atoms,  calculated their
effects, traced their bounds,  and  insulated their ele-
ments.  Such are the  rapid and wonderful results of
chemical  experiments, that one half  hour's attention
may suffice  to  throw light upon some of the most ob-
scure mysteries of nature.
  The language of chemistry, with improvements in the
science, has undergone great revolutions;  nothing can
be more absurd than the names given to different che-
mical preparations, by ancient authors ;  sometimes the 
xxviii
INTRODUCTION.
name of the inventor, sometimes the appearance or pro-
perties of the  product,  were taken as distinguishing
appellations;  the pupil  was lost in the mass of terms
which  rendered no assistance  to any systematic ar-
rangement of the substances.    As  soon  as  chemistry
was based  upon established truths; it seemed  neces-
sary to reform its  language:  after various  attempts,
our nomenclature seems at present  definitely fixed.*

  * Although when applied to chemistry in France, this remark may, with a
few exceptions, be true, yet we cannot say the same of the nomenclature of
English chemists, some of whom admit, while  others reject, that of the French.
Professor Silliman, in his Elements of Chemistry, gives his approbation to the
French nomenclature, particularly that of the salts. In this work, the Transla-
tor has generally given both the French and English names of substances. 
CHEMICAL DICTIONARY.
                          A.

   Absorbent. (From absorbeo, to suck up.)  Substances-
 are  so called by chemists, that have the faculty of with-
 drawing moisture from the atmosphere.
   Absorption.   By this  term,  chemists understand the
 conversion of a  gaseous  fluid into a liquid  or solid, or
 being united with some other substance.  Thus, if muriatic
 acid gas be  introduced into water, it is absorbed, and
 liquid muriatic acid  is formed; if carbonic acid gas and
 ammoniacal gas be brought into contact, absorption takes
 place,  and solid  carbonate of ammonia is produced by
the union of their ponderable bases.
   The term absorption is also  applied to a phenomenon
 which takes place in distilling, when the distilling vessel
 begins to cool.   The internal  pressure, which  before
 was  greater than that of the atmosphere, becoming less,
 forces the liquid  into which the tube is immersed back
 into  the  retort, often breaking  it, and causing a loss of
 the product of distillation.   This inconvenience is reme.
died by the aid of safety tubes;  one kind furnished with
 a ball is  called Welter's tube, this only opposes the as-
 cension  of the liquid  contained  in the first  flask; the
other kind of tube is  straight, and adapted to all the flasks
of Woulfe's distilling apparatus;  it should  be observed,
that  each of the tubes secures  only the vessel to which
                         3* 
30
ACE
it is  connected, from the absorption of the liquid con-
tained in that which immediately follows it.
  Acetates.   (From  acetum,  vinegar.)   Combinations
of acetic acid with salifiable bases ;  these  salts, like the
vegetable s.alts, are decomposable  by  fire ; they gene-
rally give  in their decomposition  a peculiar product,
called pyro-acetic spirit, or acid.  (See this word.)   This
product is greater, in proportion as the acid has more affi-
nity  for the base, and vice versa; thus the acetate of silver
affords none, that of copper gives a  little, while the ace-
tates of zinc and manganese furnish a great quantity. As
this  pyro-acetic spirit is always formed at an expense of
the quantity of the acetic  acid, such acetates should be
chosen as  are easily  decomposed by  heat;  as for in-
stance copper.   The residue  of the decomposition is the
metal reduced  or oxidated according to  its affinity for
oxygen, and also a certain quantity of carbon.   Most of
the mineral acids decompose the acetates, none are wholly
insoluble in water ;  the solutions of those which are very
soluble, in process of time, are decomposed and give rise
to carbonates. According to Berzelius, the quantity of the
oxygen of the oxide is to the quantity of acid as 1 to 6-414.
  This computation has reference only to the acetates of
magnesia, barytes,  strontian,  cinchonine, and quinine.
  Acetate of Alumine.   An uncrystallizable salt, em-
ployed in dyeing ; it is obtained by the  decomposition of
alum by means of the acetate of lead.  The liquor con-
tains the acetate of potash or ammonia;  in this state it is
used in the arts; according to Gay-Lussac, alum, the
sulphates of magnesia, soda, and the nitrates of potash
can  decompose it;  also the chlorides of calcium, of ba-
rium, the nitrate of barytes, and the acetate of lead.
  Acetate of Ammonia. Not capable of crystallization ■
it is  prepared by saturating with acetic acid, very  pure
sub-carbonate of ammonia, or liquid ammonia.  It differs
from what  is called in pharmacy, Spirit of Mmdererus; 
ACE
31
the latter is prepared by  saturating in distilled vinegar,
the sub-carbonate of the oily ammonia which is obtained
by the distillation of hartshorn.   This volatile super-ace-
tate crystallizes in delicate prisms.
  Acetate of Copper.   {Acitate de Cuivre.)  The sub-
deutacetate known by the common name of verdigris. It
is prepared in the south of France, by bring.ng the husks
of grapes,  after the expression of their juice, in contact
with plates of copper:  this must  be distinguished  from
the substance  often seen upon old copper  and  brass,
which is a- carbonate of copper.   The  neutral  deutace-
tate, known under the name of crystals of Venus,  is pre-
pared by dissolving, with  the  aid of heat,  verdigris in
vinegar; the  compound  is left to settle, then  carefully
decanted, in order to separate  the liquid from  the sedi-
ment ;  the liquor is then evaporated, and  rhomboidal
prismatic crystals are deposited upon little sticks placed
crossways  in the liquid.   This acetate may be  dissolved
in water, and in alcohol; the solution  forms a  chestnut
coloured precipitate with  the hydro-ferro-cyanate of pot-
ash,  and a clear blue with ammonia; the  precipitate is
redissolved in an excess of the  liquid ;  the  solution also
forms a dark brown precipitate  with sulphuretted  hydro-
gen  and the hydro-sulphurets ;  if a piece  of iron is intro-
duced into the solution, it will immediately be coated with
metallic copper.
   Acetate of Iron. {Acetate de  Fer.) It exists in three
states ;  the tritacetate is the only kind  employed in paint-
ing ;  this  is acid, red, and  uncrystallizable; it  is pre-
pared  by  exposing to the air iron  filings  mixed with
vinegar or the pyro-acetic acid.
   Acetate of Lead.   {Acetate de Plomb.)  Sugar of
lead.  The neutral acetate is  a white, sugared salt; it
crystallizes in elongated, quadrilateral prisms with dihe-
dral summits ; it is efflorescent; water which is saturated
with it boils at the same  temperatnre  as when pure; it 
32
ACE
 contains about fourteen per cent, of the water of crystal-
 lization.  It was formerly called salt of Saturn and sugar
 of Saturn.  It is prepared in large  quantities in the arts,
 by combining directly the  protoxide  of lead with  the
 vinegar of wood.   It possesses the  singular property of
 dissolving a definite  quantity of the protoxide of lead,
 and of transforming it into  a sub-acetate;  it is by this
 process that the latter salt is prepared.
   The Sub-acetate is known under the name of extract of
 Saturn.   It is susceptible of crystallization,  reddens cur-
 cuma paper, and is less soluble than the neutral  acetate.
 All the other neutral salts can decompose this, producing
 insoluble sub-salts of lead.   Almost all animal andvege-
 table substances also decompose it.  These two salts, the
 acetate and sub-acetate of lead, form a white precipitate
 with carbonic acid; that  formed with the sub-acetate is
 much more  abundant; a black precipitate is formed with
 the hydro-sulphuretted alkalies, yellow with chromic acid,
 white with sulphuric acid, muriatic acid, and the carbon-
 ate of soda,  and yellowish  white with the  tincture  of
 nutgalls.
   Acetate of Lime.  {Acetate de Chaux.)  Crystallizes
 easily  in elongated prisms ;   it is  prepared by a  direct
 process.  It is employed as  a re-agent, to detect the
 presence of oxalic acid ; it is obtained in large quantities
 in the process of purifying the pyroligneous acid.
   Acetate of Mercury.  {Ace'tate de Mercure.)   The
protacetate is the only kind used ; it is little soluble in cold
 water,  more so in warm ;  it crystallizes in little  brilliant
 spangles;  it is obtained by double decomposition,  by
 pouring into  a neutral  solution of the proto-nitrate of
 mercury, a neutral solution of the acetate of potash ; this
 acetate is  employed in pharmacy.
   Acetate of Morphine. {Acetate  de Morphine.)  Crys.
fallizes in acicular  rays;  it is little  soluble in water  but
 is  easily dissolved by the  addition of a small quantity of 
ACE
33
acetic acid.   Exposed to the action of the voltaic pile,
the morphine goes to the negative, and the acetic acid to
the positive pole; it acts with re-agents much  like mor-
phine ; it exerts a strong  action upon the animal eco-
nomy.
   It  is prepared directly  by combining  morphine with
acetic acid, dissolving  it in distilled water, and causing
the solution to be evaporated by a slow heat.
   Acetate of Potash.  {Acetate  de Potasse.)   It was
known formerly under  the  name of terra  foliata tartari.
It is a white  salt, very  deliquescent, crystallizes in little
spangles ;  it is employed in medicine.  In order to pre-
pare  it, very pure sub-carbonate of potash should  be ob-
tained ; distilled  vinegar should be put into a vessel  of
wood, earthen, or silver; to the vinegar is  then added, by
small quantities, the sub-carbonate of potash in solution,
until the liquor is but still slightly acid ; it is then  left to
settle, and afterwards filtered,  in order to separate the
silex, of which the sub-carbonate of potash always depo-
sites a little ;  after this process, the liquor is evaporated
to dryness.   The  acid should be a little in excess, be-
cause a small quantity  of it escapes during evaporation.
The potash in that case, being predominant, would act
upon the vegetable matter of the vinegar,  and colour the
liquor.   It is for  this reason that the vinegar should not
be poured upon the potash ; for the portion of the potash
which is not carbonated, would act upon  the vegetable
matter of the vinegar, and colour the salt;  a circumstance
which does not  take place when the alkali is gradually
introduced into  the  acid.   In order to  obtain this salt
perfectly white, it should be melted in a silver basin ;  it
will in the first stage  of the process be black, on account
of a little carbon which is formed at the expense of the
acetic acid ; this  substance is employed to rectify alcohol;
but for medicinal uses,  this  mass  should be dissolved in
distilled water, the solution filtered and  tested;  (if not 
34
ACE
 found to be  neutral,  it  must be  remedied;) it  is then
 slowly evaporated to dryness in a silver basin.
   Acetate of Soda. {Acetate de Sonde.)  It is prepared
 like  that of potash;  it crystallizes easily.   Its crystals
 have some  resemblance to those of the sulphate of soda,
 when the crystallization of the latter has been disturbed;
 but they are  easily distinguished  by pouring upon them
 a little concentrated sulphuric acid.   The acetate of soda
 might easily be confounded with the  acetate of potash;
 the former,  however, differs from the latter, in being better
 crystallized, and unalterable by the air.
   The muriate of platina can also be used to distinguish
 them, and in case of a mixture of these two acetates, they
 may  be  separated by  alcohol at  104° F.  which dis-
 solves the  acetate  of potash, but has no effect upon the
 salt at the base of the soda.
   Acetites.   See Acetates.
   Acids.   These  are  compounds  which,  generally,
 redden blue vegetable colours, have a taste more or less
 sharp, go to the positive pole of the voltaic pile when they
 are not  decomposed ; they all possess the  property  of
 combining with metallic  oxides, with ammonia and sali-
 fiable vegetable bases, of neutralizing them, and giving
 rise to compounds named salts.
   All the acids  are more or Jess soluble in water; they
 are distinguished into binary acids, which are the result of
 the combinations of a  simple combustible  body with
 oxygen or hydrogen, and ternary which result from the
 combination of more than two bodies.  Each of these
 divisions  has been subdivided into two  sections.   In the
 first division are found the oxacids or the products of the
 combination of a simple body with  oxygen,  and the hy.
dracids or products of the combination of a simple body
with hydrogen.
  The second division is subdivided into vegetable and
animal acids,   The  acids exist in a gaseous, liquid, and 
A  C I
35
solid state ; they present characters too various to be in-
cluded under a general description.
  Acid Acetous.   See Acid Acetic.
<■ Acid Acetic.  {Acide Acttique.) Of all the vegetable
acids,  the  acetic  acid is the  most  common, the  best
known, and  the most extensively  used.   Equally  pro-
duced by nature and by art,  it is found in a great number
of vegetables  and  vegetable productions.   It is one of
the  principal products of the  acid fermentation.  Vinegar
is a combination of this acid, with a greater or less quantity
of water, a vegetable mucous matier,  a small quantity of
alcohol and many  salts in solution in  the water.  The
vinegar which is made from  the fermentation of wine,
contains a certain quantity of the super tartrate of potash,
which maybe obtained by evaporation.
  Pure  acetic acid crystallizes,  or  rather forms  a crys-
talline  mass,  at 56°  F.  Its density is 1-063 at the tem-
perature of 61° F.   It is volatile.    uallerat, who  has
published an interesting work upon this acid, regards it at
1-063 of density, as  a compound of 11-92  of water, and
88-08  of real  acid.  According  to Gay-Lussac  and
Thenard, it is composed of  carbon, 50-229, oxygen 2-2,
12-7 ;  hydrogen 5-629;  or  in volume,  of 3  volumes of
oxygen, 14 of  the   vapour" of  carbon,  and 6  of hy-
drogen.  It is usually  obtained from  the  acetate of
copper, called crystals of Venus ; for this purpose, the
salt is put into a stone retort, to which an adopter, and
receiver are  fitted,  to the  latter is  connected  a tube,
which is placed under water.  A slow heat is applied, and
the  fire gradually increased.  The acetic acid, which is
coloured green  by  a small portion  of the  acetate re-
maining in combination, passes into the receiver.  Before
using, it is  distilled  anew,  but in a glass retort.   In the
stone retort there remains a brown powder, which appears
to be a mixture  of metallic  copper minutely subdivided 
30
ACE
with a little carbon, and perhaps a little of the protoxide ol
copper.
   In the  arts,  acetic  acid  is  also  obtained from the
acetate of soda ; but as this salt is not easily decomposed,
its decomposition is assisted by a determinate quantity of
sulphuric acid.   Acetic  acid is also  obtained  by pu-
rifying the pyroligneous  or  empyreumatic  acetic  acid,
which is procured from the carbonization of wood in close
vessels.   The oil or liquid tar which swims upon the top,
is first separated from the acid product, and the latter is
then saturated with lime.   An  acetate of lime is now ob-
tained ; this, by double decomposition with the sulphate
of soda, produces an acetate of soda and the sulphate of
lime, which  is precipitated.    The liquor  is then evapo-
rated, the residue is a crystalline mass impregnated with
tar;  this is  purified by heating it sufficiently to  inflame
the tar;  the  burnt  matter is  then diluted with water, fil-
tered and crystallized.   It is often necessary to repeat the
crystallization, in order  to  obtain  crystals  sufficiently
pure, they are then treated with sulphuric  acid.  The
acetic acid thus obtained,  usually contains a considerable
portion of acetate of soda.  A salt, known  by the name
of salt of vinegar, is prepared by impregnating crystals of
the sulphate of potash with concentrated acetic acid.
  Acid Amberic.   {Acide Ambreique.)  Pelletier and
Caventon discovered this acid in ambergris.  It is yellow
in the mass, and  white when  pulverized.   It fuses at
212° F. does not yield ammonia in its decomposition, is
little  soluble in cold water, dissolves more  easily in al-
cohol and ether.  The  amburate of potash forms a yellow
precipitate with the soluble salts  of  lime, iron, copper,
barytes, acetate  of  lead, nitrate of silver, and  the chlo-
rides of mercury and gold.
  Acide Antimonious.   See Oxides of Antimony.
  Acid Arsenic.  {Acide  Arsenique.)  White   solid
uncrystallizable, deliquescent, and of course very soluble. 
A  C  I
35
\t  is not Volatile, reddens deeply the tincture of litmus.
Its specific gravity is 3-391.   It forms  soluble salts with
potash, soda, and ammonia.   The waters of barytes and
lime form in this acid white  precipitates of insoluble ar-
senates ;  these are, however, soluble in an excess of ar-
senic acid.  It forms with sulphuretted hydrogen, a light
yellow precipitate, which is a sulphuret of arsenic ; with
the nitrate of silver it forms a precipitate of a deep brick
ted, which is the arseniate  of silver.   The  arsenic acid
nxercises  no action either upon the  muriate, or upon the
acetate of cobalt, but forms  a rose  coloured precipitate
with the muriate of ammoniacal cobalt;  this precipitate is
the arseniate of cobalt.  To obtain this, it is necessary
to  make use of a concentrated solution of arsenic acid,
nnd to  employ but 4 or 5 drops; if the water is slightly
charged  with acid,  the precipitate will be  blue, light
violet,  or bluish red ; the muriate of ammoniacal cobalt,
though susceptible of giving in water precipitates of these
colours would be decomposed by the great quantity of the
liquid contained in the  solution ; but if too much acid is
employed, the precipitate is redissolved  as soon as formed.
{Orfila, Toxic, generate, p. 237.)
  Arsenic acid is prepared by introducing into a glass  re-
tort of sufficient size, 1 part of white arsenic (deutoxide of
arsenic) with  2 parts of liquid muriatic acid, and 4 parts
of concentrated nitric acid, an adopter and  receiver are
fitted to the retort, which is gradually heated  until the
liquid  boils.  The  heat must be continued until  a sub-
stance is formed of the consistence of sirup;  it is then
turned into a capsule and evaporated to  dryness.
   Acid Arsenious.  See Oxide {deuto) of Arsenic.
   Acid Auric.  A  term proposed  by Pelletier, for the
peroxide  of gold; its  alkaline compounds are termed
anrates.
   Acid  Benzoic.   {Acide  Benzoique.)  Solid, white.
volatile, capable of being crystallized  in acicular sat,in<
                           4 
38
A  C I
like prisms, inodorous when pure, soluble in 24 parts of
boiling water and 200 parts of cold water, in one part of
boiling alcohol and two parts of alcohol at the ordinary
temperature, equally soluble in  nitric acid, without being
decomposed.  According to Berzelius, it is composed of
carbon  74-71, oxygen 20-02, hydrogen 5-27; or in vo-
lume, of carbonic acid gas 5, oxygenl,hydrogen4. Itexists
in balms, some animal substances, the flowers of melilot,
vanilla,  &c.  Art has not yet'been able to create it.  It
is usually obtained  from the benzoin.*  The benzoin,
reduced to  powder, is put  into  an earthen  pan, this is
covered by another pan, with a small aperture to admit
the  passage of the gas; a piece of paper is then put
around the two pans, at the edges where they meet, and
a moderate heat is applied ; the acid soon sublimes, and
attaches itself to the upper  pan.   There is a  more expe-
ditious method of collecting this acid than the one above
described ; but  it  is  usually employed  to  exhaust the
residue from the benzoin which has furnished the greater
part of its acid  by sublimation; this process  consists in
pulverizing  the  remainder, and  boiling it for some time
with milk  a little  charged with lime.  The boiling liquid
is decanted, the dregs being washed in order to obtain
the remaining acid ;  muriatic acid is introduced into the
liquid, which forms with the lime a soluble muriate, while
the acid, little soluble, is precipitated, accompanied by a
certain  quantity of resin.  When the liquor is cold, the
sediment, which  has a strong odour of vanilla, is dried,
and, mixed with a little charcoal, and then sublimed.  In
order to obtain it free  from resin, it must be  heated  in a
glass retort with an equal weight of nitric  acid, at 77°
until the  mass  be  entirely dry.   The resin  is then des-
troyed ; and by dissolving  the residuum in boiling water.
 and leaving it to cool, beautiful  crystals will be produced:
* Stttrax Benzoe> 
A  C I
39
  Acid Boletic.   A substance  obtained by Braconnot
from the  boletus pseudo-ignarius.  Its crystals are pris-
matic,  and require  180  parts  of water  at 68°, and  45
of alcohol, for  their solution.   This reddens blues, and
precipitates  nitrate of lead and the  salts containing the
peroxide,  but not those of the protoxide of iron.  The
acid sublimes  with little  alteration, when  heated.
  Acid Bomhic.  {Acide Bombique.)  An acid obtained
from silkworms by M. Chaussier. It is supposed by some
to be the same as the acetic acid.
  Acid Boracic.   {Acide Borique.)   Solid, colourless,
inodorous, fusible above red heat, not volatile, except in
certain cases.  (See the super-tartrate of potash.) It offers
acid characters  but in a slight degree.   It was formerly
knownunder the name of sedative  salt of Homberg, or nar-
cotic salt.  Gay-Lussac and Thenard succeeded in decom-
posing it; and  demonstrated that it was a combination of
oxygen with a principle which the\ named  boron.   Ac-
cording to these chemists, it appears that potassium and
sodium are the only bodies which can decompose boracic
acid;  and this  decomposition takes  place but at a high
temperature.   Boracic  acid  is formed  of one  atom of
boron  and two  atoms of oxygen :  this gives for the weight
ot the  atom of boracic  acid, 24.*  It  is little soluble in
cold water,  more so in warm ;  and when cool, crystallizes
in pearly spangles: this appearance, according to Robi-
quet, is owing to an oily matter which the borate of soda
retains.   It was with ihis last substance that the boracic
acid was formerly prepared; it  is now found  in  large
quantities in the waters of certain  lakes.   In order to
extract the  acid from the sub-borate of soda, it is neces-
sary to melt the salt  in seven  or eight parts of water;
into this liquor  must be poured  the diluted white of an
 egg;  the liquor is then filtered; when  partly cool, 750

       * 1 atom of boron = 8; 2 atoms of oxygen = 16. 16+8 = 24, 
40
A C  }
 grammes* of sulphuric acid are by slow degrees added
 to a kilogramme of the salt.   The liquor  being cooled,
 the supernatant liquid is decanted ; the acid washed with
 cold water; the  mother  waters and  the waters of the
 washing are  then united, evaporated, and  crystallized ;
 the  acid  is spread upon  paper, and  placed in a situa-
 tion to be dried by a moderate heat.   As in this state it
 retains a little sulphuric acid and a little uily matter, it is
 necessary, in order  to  obtain  it very pure, to melt  it in
 a crucible, dissolve it in water, crystallize it, redissolve,
 and preserve it in a bottle closely stopped; it is used  in
 medicine.
  Acid Butyric.   {Acide Butyrique.)  Discovered  by
 Chevreul  in butter, which contains a small quantity of it
 in a free state ;  it is obtained by treating the butyrate of
 barytes with sulphuric acid.
  This- acid is a liquid, nearly colourless, odorous, having
 at 50° a density of 0-9675.   It is not solidified at —15°.
 does not  boil at  212°;  it  dissolves in  water, is  easily
 inflamed upon the  approach  of  a burning substance;
 it forms with bases neutral salts, in which the  quantity
 of the oxygen of the base is to that of the acid as 1 to 3,
 and to the acid itself as 10-3 to 100.
  Acid  Camphoric    {Acide   Camphorique.)   Solid,
 forms plumose crystals of a bitter taste, little soluble in
 water, more so in alcohol, volatile oils, and mineral acids;
it is always the  product of art, being  the result of the
 action of a large proportion of nitric acid upon camphor,
 requiring  14 parts, at 77° to  1  of camphor.
  Acid Capric.  {Acide  Caprique.)   Is found  in soap
 made with the  butter obtained from cow's milk ; it ap.
 pears in  the form of little colourless  needles  at 62° ;
 it is  liquid at 65° ; its density is 0-9103; it is  very

  * A gramme ia a French weight of little less than 19 grains; a kilogramme i^
 1000 grammes. 
A  C I
41
soluble in alcohol, scarcely soluble in water;  it unites to
salifiable  bases, and forms  neutral  salts, in which  the
quantity of the oxygen of the oxide  is  to  that of  the
acid,  in the proportion of 5-89  to  100.  Its name i?
given  on account of its having a peculiar smell, resem-
bling that of a goat,  {caper.)
  Acid Caproic.   {Acide Caproique.)  Exists in  the
soap made from the  butter of goat's milk ; it is in most of
its properties similar to the acid above described, except
that it  is liquid ; like  that, it combines  with salifiable
bases ;  in the  salts which  result from this combination,
the quantity of the oxygen of the oxide is to that of the
acid as 7-5 to 100.
  Acid Carbazotic.  A peculiar acid resulting from the
action of nitric acid  upon indigo.  It appears in yellow
crystalline scales, and  is dissolved readily by ether and
alcohol.  It acts like a strong acid upon metallic oxides,
and yields crystallizable salts.
  Acid Carbo-Muriatic.  {Chloroxi-Carbonique.)  See
Acid chloro-carbonus.
  Acid Carbonic.   {Acide  Carbonique.)  Known  for-
merly under the  names of calcareous acid, carbonaceous
acid, vitiated air, aerial acid, &c.  Carbonic acid is now
perfectly well understood ; it is one of the constituents of
carbonate of lime, which forms immense beds, and chains
of mountains; carbonic acid exists in the waters of many
springs, and the air  of the atmosphere always contains a
certain quantity.   It is composed of one volume of  the
gas of carbon,  and  one of oxygen; in weight 27-67 of
carbon, and 72-33  of oxygen; its  density is 1-5245, it
is of course heavier than atmospheric air.   It may be
poured from one vessel to another in  the same manner
as liquids ; it collects in low places, wells, cellars, and gal-
leries of mines.   It  is fatal to animal life.   Its presence
may be detected by  means of a lighted taper which this
gas will extinguish-   It is a colourless gas, with an odour
                           4* 
42
A  C i
somewhat  sharp;  it has been liquified  by exposure
to cold, and considerable pressure  at  the  same  time.
It can be combined with water, by  means of a con-
densing pump; water may be charged  even with  many
times its own volume of gas,  and by this process, natural
mineral waters are imitated.  Water containing a very
small quantity of this gas, gives a white precipitate with
lime water.   This precipitate which is the carbonate of
lime, may be redissolved by  an excess of acid.
   This water has a sourish taste, and if submitted to  a
temperature  slightly elevated, throws off  in the form of
bubbles, all the acid which it contained.   Carbonic acid
gas extinguishes combustion, and destroys  the respiration
of animals.   According to  Gay-Lussac and Thenard,  it
can  be decomposed by potassium and sodium; in  the
former case  with the disengagement of caloric and  light;
in the latter of caloric only; the metal is oxidated,  and
the carbon  set free.   The acid is entirely  decomposed
when the metal is in excess ; if the metal is not in excess,
the acid is in part absorbed.
   Carbonic  acid is  procured either by calcining a car-
bonate, or separating it from its combinations by means
of an acid.   White marble is generally  chosen  as  being
the most pure  carbonate of lime ;  upon  this is poured
either sulphuric  acid, or  diluted  muriatic acid;  the
former is preferable  because it is not volatile, and of"
course  does  not pass off with the disengaged  carbonic
gas;  but it is attended with  the disadvantage of forming
around the pieces of marble, a crust of sulphate of lime,
which diminishes the action of the acid; it is necessary
to shake the decomposing mass from time to  time, and to
wash the  gas before  collecting  it.   (Pelletier  and Ca-
venton.)
   Acid Caseic.   {Acide Caseique.)  It is of a yellow
colour, of the consistence of sirup, and of the taste of
cheese; it is bitter and  sour;  nitric  acid transforms  it 
A  C 1
43
into  oxalic  acid ; it  gives  off ammonia  by distillation.
Chlorine, lime water, acetate of lead, and muriate of tin,
do not act upon  it.
  Acid Cevadic.  {Acide Cevadique.) Exists in the form
of needles, or crystalline concretions, of a beautiful white,
soluble in water, of a colour analogous to that of the bu-
tyric acid ;  it melts at 68° F. and sublimes at a moderate
heat, without decomposition.  It is soluble in ether  and
alcohol ; and  forms with bases, salts which have little
odour. The cevadate of ammonia precipitates white the
salts of the  tritoxide  of iron.   The  cevadic acid  is ob-
tained  by treating with potash,  the oily substance  which
by ether is separated from the cevadilla veratrum sabatilla;
a saponaceous mass is  formed, which being diluted with
water, and  precipitated by tartaric acid, furnishes a li-
quid, in which is found the  cevadic acid.   This liquid is
distilled ;  the acid passes into the receiver ; it is saturated
by barytes, the cevadate of barytes is decomposed by
phosphoric acid ; the pure acid  is then obtained by a new
distillation.
  Acide  Chlorous.   {Acide Chloreux.)   See Chloric
Acid.
  Acid  Chloric.   {Acide Chlorique.)  Liquid, colour-
less, inodorous ; it first reddens litmus paper,* and after a
few days deprives it of colour,  (Vauquelin ;) it does not
efface the colour of indigo.  Dissolved in sulphuric acid
at a high temperature, it is  decomposed into chlorine and
oxygen ;  it  is, even at the ordinary temperature, decom-
posed by hydrogen, sulphuric, and sulphurous acids.  Ni-
tric acid does not produce the same effect, nitrate  of sil-
ver does not affect it; in weight it is composed of 100 of
chlorine, and 111-68 of oxygen ; in volume  1 of chlorine,
and 2\ of oxygen.   This acid is not found in nature ;  it
is obtained by dissolving the chlorate of barytes in water.
* Paper coloured by matter extracted from the Lichen procclla; 
11                     A C  I
 and pouring upon it, by degrees, weak  sulphuric acid.
 until the liquor ceases to be affected by the acid, or by the
 barytes ;  the liquor is then filtered, and gently evaporated
 to an oily consistence.   Gay-Lussac first succeeded in
 obtaining it; and to him we are indebted  for the investi-
 gation of its properties.
  Acid  Chloric  oxygenated.   {Acide Chlorique oxi-
gene.)  Hyper-Oxymuriatic  Acid.  Without odour  or  co-
lour; it does not precipitate the nitrate of silver, differs from
the chloric acid in reddening the tincture of litmus instead
of destroying its colours ; it is not decomposed by chloric,
sulphurous or hydrosulphuric acids ;  it unites to  bases,
and gives rise to peculiar salts.  It is composed of 100 of
chlorine  and 159-79  of oxygen, or  in volume of 1  of
chlorine  and  3± of oxygen.   {Gay-Lussac, Ann.  Chim.
ct Phys.)  It is extracted by sulphuric acid from the oxi-
genated  chlorate of potash.   It was discovered  by M.
Frederic Stadison.
  Acid   Chloro-Cyanic.    {Acide  Chloro-Cyanique.)
Chloroprussic Acid.   Known also  by the name of oxyge-
nated Prussic acid; when pure it is liquid at the ordinary
temperature, but when mixed with carbonic acid it is
gaseous.  In this state it is colourless, of a sharp  odour,
its density is 2-111; it is soluble in water, the solution i?
not precipitated either by that of barytes or by the  nitrate
of silver.  It is absorbed by the alkalies ; and if an acid
is then poured upon  the alkalies, an effervesence takes
place, carbonic acid is eliminated, and ammonia and mu-
riatic acid are formed.
  The chloro-cyanic acid precipitates green the solutions
of the  protoxide of iron; this precipitate becomes a beau-
tiful blue by the addition of sulphuric acid, a sulphate or
a hypo-nitrate ; but if potash is mixed with the chloro-cy-
anic acid, before adding the salt of iron, this precipitate
is not formed.
  This acid is obtained by passing a current of chlorine 
A  C I
45
through  hydro-cyanic acid, (prussic acid,) until  this li-
quid can destroy the colour of sulphate of indigo.  It is
heated to disengage the excess of chlorine, and  agitated
with mercury ; on being  distilled, a mixture  of chloro-
cyanic, and carbonic acid is  obtained.  This discovery
was made  by Berthollet, but  the  properties of  the acid
were first investigated  by Gay-Lussac.  This  chemist
found it  composed of 1 volume  vapour of carbon, i vo-
lume of nitrogen, and i a volume of chlorine.
  Acid Chloro-Phosphorous, and Chloro-Phosphoric.
See Chlorides of Phosphorus.
  Acid Chloro-Sulphuric. {Chlorure de Soufre.)  See
Chloride of Sulphur.
  Acid  Chloro-Carbonous.    {Acide Chloroxi-Carbo.
nique ; Carbo-Muriatique.)  This acid is obtained by ex-
posing to the sun a mixture of chlorine, and the Oxide gas
of carbon, in a very dry state.  The mixture will  soon
lose a part  of its volume,  and be changed into a  colour-
less gas of  a strong odour, which  extinguishes comhus-
tion, reddens litmus,  and has a density of 3-399 ; this is
the  chloro-carbonous acid gas; tin,  zinc,  arsenic,  and
antimony, absorb the chlorine, and set free the oxide of
carbon.  Water decomposes it, giving place to carbonic
and muriatic acids.   Alcohol  dissolves twelve times its
volume at the ordinary temperature ; this gas can absorb
four times its volume of ammoniacal gas, and then forms a
a deliquescent volatile salt.  It was discovered, and first
investigated by Mr. John  Davy.
  Acid  Cholesteric.  {Acide  Cholesterique.)  Solid,
orange yellow when in a mass, in white acicular crystals
when derived from spontaneous evaporation of a solution
of alcohol.    It fuses  at 137*  ;  it does not give off am-
monia in its decomposition.   Sulphuric acid, charcoal,
and nitric acid, dissolve it at all temperatures ; it is inso,
luble in  the oil of  olives, castor oil,  the oil of sweet
almonds, and vegetable acids; it is sufficiently soluble in 
10
\ C I
water to redden  litmus;  it is  very soluble  in  alcohol.
ether, and the volatile oils.  It  is obtained from  cholesle-
vine, by nitric acid.   The discovery of this acid was made'
by  Pelletier  and  Caventon.   (Journal of  Pharmacy.
vol. HI.)
  Acid Chromic.  {Acide Chromique.)  Solid, of a pur-
plish red, uncrystallizable when  pure, reddening litmus
paper very strongly, attracting moisture from  the air, and
by heat decomposable into an oxide of chrome and oxy-
gen.  Sulphuric acid decomposes it, and  produces  a
sulphate  of chrome.  Its discovery is due to  Vauque-
lin.  Berzelius considers it as  composed of one  atom of
chrome, and three of oxygen.   It exists in nature in  com-
bination in the ruby, and in the chromate of lead, which
have as yet been found only in Siberia and Brazil. Chro-
mic  acid  is  extracted  from  the  chromate of  barytes
dissolved  in  diluted nitric acid;  into  this  is  poured
a  little weak  sulphuric  acid  ;  a precipitate  of the
sulphate  of barytes being formed, it is separated by fil-
tering, and the liquor is  slowly evaporated to  dryness.
The nitric acid volatilizes, and the chromic acid  remains
in the capsule.
  Acid Curomo-Sulphuric. {Acide Chromo-Sulphurique.)
It is obtained from a mixture of sulphuric acid, and chro-
mic acid.   Gay-Luasac, who examined this  compound,
considered it as formed of one atom of chromic acid, and
one atom of sulphuric acid.   It may  be  crystallized in
quadrangular prisms ; it is of a deep red, and deliques-
cent.  Its action upon concentrated alcohol  is very re-
markable ; an explosion takes place, a little ether, and a
sweet oil of wine are formed, and the acid is left in the
state of a green oxide of chrome.
  Acid Chyazic.  {Acide Chyazique.)  A name given
by Porrest to the hydrocyanic acid from the initials,  c. 11.
a. carbon,  hydrogen, and azote,* which constitute this
* French name for nitrogen 
V C I
47
■«cid.   He gave  also the names ferruretted,* argentu-
retted,f sulphuretted chyazic  acid, to the hydro-ferro-
cyanic acid, and to the combinations of the hydro-cyanic
acids with sulphur and silver.
  Acid Citric.   {Acide Citrique.)   Solid, white, crys-
tallizes in rhomboidal prisms.   If exposed in a glass re-
tort to a temperature a little elevated, it will soon be de-
composed, and the receiver will be found to  contain an
empyreumatic oil and pyro-citric acid.  It forms a white
precipitate with the waters  of  barytes and strontian, but
these precipitates redissolve in an  excess of acid.  If
acts upon the acetate of lead, but not upon the nitrate of
mercury or the nitrate of lead.  Nitric acid transforms
it into oxalic acid.   According to Gay-Lussac and The-
nard  it is composed  of carbon 33-811, oxygen, 59-859.
and hydrogen 6-330.  The  results of Berzelius' experi-
ments differ; he states the constituents to be, carbon
11-40, oxygen 54-96, and hydrogen 3-64.   This acid ex-
ists in a free state in a great number of fruits, but it is
usually extracted from the juice of the lemon.   For thi.s
purpose, the acid contained  in the juice is saturated by
the subcarbonate of lime ;  the citrate of lime which is
thus formed,  is  then washed,  decomposed by sulphuric
acid; the supernatant  liquid  is treated with  charcoal,
as in the preparation of tartaric acid.  (See this acid.)
  The  citric acid being an expensive article, it has been
found easy to  adulterate it by adding a quantity of tar-
taric acid.  This fraud maybe easily discovered, by con-
sidering that the tartrates with  excess of acid are almost
wholly insoluble in  water. If a solution of potash be
poured upon a solution of citric acid, there will be, if the
potash  is carbonated,  an escape of carbonic acid, and
the liquor will remain limpid ;  but if this  same alkaline
solution be poured  upon tartaric acid, the result will be
; From ferrum, iron.      t From argtutum, silver- 
18
A  C I
 an acid tartrate, which being soluble only in a great quan
 tity of water, is precipitated.
   Care must be taken that there is not sufficient potash to
 saturate the tartaric acid, as by an exception to a law com-
 mon to a great number of salts,  the neutral tartrate  of
 potash  is  more soluble than  that  which  contains  an
 excess of acid.
   Acid Columbic.   {Acide  Columbique.)   This is one
 of the acids which contain the least oxygen.   According
 to Berzelius, 100 parts of metal would contain but 5-485
 of this acid.   It was discovered by Hatchett; it is white,
 capable of being pulverized, inodorous, insipid, and little
 soluble in water, still less so in nitric and sulphuric acids ;
 it does not dissolve well except in  potash and soda, with
 which it forms salts.   Citric, tartaric,  and  oxalic acids
 dissolve it when it is hydrated.   Tt is found  in combina-
 tion, and always in small quantities in nature.  It is ex-
 tracted from its  combinations  with  the oxides of iron,
 manganese and yttria.
   Acid Cyanic.  {Acide Cyanique.)  A name first given
 by Gay-Lussac and Liebig  to the  acid which they  now
 call fulminic acid.  See Fulminic Acid.
   Acid Delphinic.   {Acide Delphinique.)  SeePhocenic
 Acid.
   Acid Ellagic.  {Acide Ellagique, so called by an in-
version of the word galle, gall.)  The discovery of this
acid was made  by Chevreul.   It  is in the  form  of a
whitish powder, insipid, almost insoluble  in water,  al-
cohol, and ether.   Nitric acid decomposes it, colouring it
a deep red, and transforming it into oxalic acid.  If heat-
ed in a retort it gives a carbonaceus residuum, and a yel-
low vapour, which in condensing produces acicular trans-
parent crystals.   It exists in  nutgalls with gallic acid.
It is obtained by collecting the crystalline deposite which
is formed in an infusion of nutgalls, dissolving in boiling
water the acid contained in this deposite, bringing the re- 
A  C 1
to
siduum in contact with a weak solution of potash, filtering
the liquor, and leaving it to the action of the atmosphere ;
*he carbonic acid of the atmospheric air gradually com-
bines with it and  forms a precipitate of ellegate of pot-
ash.  This  is washed, and  treated with weak muriatic
acid, which combining with the potash sets free the elle-
:»ic acid ; it  is then purified by washing.   The ellegate*
have been  little  studied.    Thenard  considers  as ?
neutral ellegate of potash, a soluble salt which greens the
sirup of violets, and as an acid ellegate of potash, an in-
soluble white salt.
   Acid Fluo-Boric.  {Acide Fluo-Borique.)   A colour-
less gas of a strong odour, reddening litmus paper, and
strongly attracting humidity  from  the air.   Its specific
gravity is 2-371;  it is very soluble in water, which can
dissolve twice its  weight, or 700 times its volume.   The
water which is saturated by it, is frothy, very caustic, and
if heated, loses one fifth of  the gas which it contains.
Of the  metals, potassium and sodium (and  these require
the aid of heat) can alone decompose it, caloric and light
at the same time being disengaged.   From this decom-
position result boron,  and  a proto-fluate  of  potash or
soda.  It does not act upon glass like fluoric acid.   It is
obtained by  treating with sulphuric acid, a mixture of pu-
rified boracic acid, and fluate of lime.  The  honour of
its  discovery and the  investigation of its  properties are
due to  Gay-Lussac and Thenard.
   Acid Fluoric.  {Acide Fluorique.)   So called because
it is obtained from  fluor spar, or fluate of lime.   A co-
lourless liquid of a  sharp  odour, strongly reddening lit-
mus.  It  boils at 86°  and remains  liquid at a cold of
40° below 0.  Its action upon potassium and  sodium is
verv powerful, resulting in the disengagement of a large
qnantity of hydrogen, and a proto-fluate of potash, or soda.
|t acts,  though with less intensity,  upon  iron, .zinc, and
manganese.
                          5 
50                     A C  1
   When mixed with water, the operation must be gradu^
 ally carried on, since its affinity for this liquid is such, that
 an explosion will take place, if great quantities of the two
 substances are at once brought together.
   There is in the mixture of water with this acid a very
 considerable elimination of caloric.   This acid combines
 readily with silex and  boracic  acid, forming two peculiar
 acids.   (See Fluo-Boracic and Silicated Fluoric Acid.)
   Fluoric  acid  is, by  many chemists, supposed  to  be a
 compound of hydrogen and a radical, which they call pli-
 tor or fluor, as the hydro-phtoric, or hydro-fluoric acids ;
 others whose authority is of equal weight regard it as an
 oxacid ;  such is the opinion of Gay-Lussac and Thenard.
 to whom we are indebted for learned researches upon thi.<-
 acid, and who first obtained it apparently pure.  It is em-
 ployed for  etching glass ; and is obtained by treating the
 fluate of lime with sulphuric acid.
   Acid Fluoric  Silicated.   {Acide Fluoriqite Si/icd.)
 See Fluate Acid of Silex.
   Acid Formic. {Acide Formique.) From Formica an ant.
 This acid is liquid  even below 0, colourless, of a sharp
 and penetrating odour.  Its density is 1-116 ;  this is great-
 er than that of acetic acid.  Being mixed at the ordinan
 temperature with  concentrated  sulphuric acid, it  decom-
 poses into  water  and  an oxide  of carbon;  and heated
 moderately with the nitrate of mercury or of silver, it is
 reduced  to  water  and carbonic acid.   According to Ber-
 zelius it is composed of 2-86 of hydrogen, 64-67 of oxygen,
 and 32-47 of carbon.  It is obtained from ants, by a com-
 plicated  process.   (For the details of this process,  See
 • Annals of Chemistry and Physics," vol. 20.)
  Acid Fulminic.   {Acide Fulminique.)  From fulmi-
natio,  detonation.   This acid is  white  and pulverulent
little soluble in cold  water!   It crystallizes on  cooliii.-.
reddens litmus, and forms with different bases many de-
tonating salts.   In order toobtain  this  acid, the fulminate 
A  C I
51
"i silver (fulminating powder of silver) is decomposed
by lime ; this  forms  a soluble fulminate of lime, and a
precipitate of the oxide of silver.  After being filtered,
the liquid is concentrated by a moderate heat, and treated
with nitric acid ; this forms a nitrate of lime, which re-
mains in the liquor, whilst the acid is  precipitated.  For
the knowledge of this new acid we are indebted to Gay-
Lussac and Liebeg.  It appears  from their  analyses, to
be composed of cyanogen, oxygen, and a little of  the
oxide of silver.
   Acid Finnic.   {Acide Fungique.)  From  fungus  a
mushroom.   Discovered by Braconnot, in mushrooms. It
is colourless,  uncrystallizable, deliquescent, of a very
sharp  taste.    It forms  with  ammonia an acid fungate,
which crystallizes in hexahedral prisms ; and with potash
and soda, uncrystallizable salts very soluble in water,  but
insoluble in alcohol.
   Acid Gallic.   {Acide  Gallique.)  Exists  chiefly in
nutgalls, where it is  united  to tannin.   It is  extracted
from  this substance.   Many  processes  for obtaining it
have been proposed ;  that of Chevreul appears to be  the
most simple.  It consists in  putting  an infusion of nut-
galls, about three quarts, into a flask, and leaving it to re-
main  some time closely corked.   It forms a deposite, from
which is  extracted the  fungic acid.  (See  this word.)
In process of time  there will  form upon the  surface  a
coat of mould; when this coat is  sufficiently  thick, the
flask is exposed to a temperature two or three degrees
above zero; a collection of little white  crystals is then
deposited;  these are the gallic acid.  These crystals are
dissolved  in cold  water,  filtered,  the solution is  eva-
porated, and the gallic acid again crystallized.   Chevreul
recommends to wash the filter with diluted muriatic acid,
in order that it may act upon the sub-carbonate of lime
and the peroxide of iron, with which the paper is liable to
be impregnated. 
A  C I
   The  gallic acid appears  in white brilliant  aciculai
crystals, with an acid taste, soluble in 3 parts of boiling
water, equally soluble in  alcohol  and nitric acid; nitric
acid at first renders it purple, then yellow, and at length
transforms it into oxalic acid.  It forms a greenish pre-
cipitate with the waters of lime, barytes, and strontian ;  h
colours all the solutions of the peroxide of iron deep blue,
and precipitates the acetate of lead white.  It is according
to Berzelius in  weight composed  of 38-36 of oxygen,
56-64 of garbon, and 5 of hydrogen.
   Acid Gluic.  See Acid Oleic.
   Acid  Hirsic.   {Acide  Hircique.)    Liquid   at  32°.
lighter than water, of the odour of a goat and acetic acid,
volatile,  soluble in alcohol  and little soluble in water,
reddens litmus, forms with potash a deliquscent salt, and
with ammonia a salt which has a strong smell.  It was
discovered by Chevreul, while examining the  action of
the alkalies upon hircina, a  substance, which he found
with elaine and  stearine  in  the fat of the goat {hircus,)
and sheep.
   Acid  Honigstic.   A name given to  Mellitic Acid.
(See this word.)
   Acid Hydriodic.  {Acide Hydriodique.) A colourless
gas of a strong odour, diffusing white vapours, and extin-
guishing combustion.   Its density is 4-4288.   It may be
decomposed by oxygen, chlorine, potassium, sodium, and a
great number of metals ;  sometimes the hydrogen is ab-
sorbed, and  the iodine set  free;  sometimes the iodine
enters into new combinations, and the hydrogen is  dis-
engaged.
   This  acid  is very soluble  in water.  The weak  hy-
dracids and the oxacids do  not affect it, but  nitric and
sulphuric acids  set the iodine  free, by forcing  the  hy-
drogen  into new combinations.   Chloric  and iodic
acids are affected in the same manner.   The hydriodic
acid forms with the acetate of lead, a yellow precipitate 
A  C I
5a
 with the deuto-nitrate of mercury, a white precipitate, in-
 soluble in  ammonia; this is  of course the  iodiae  of
 silver, since,  of  the different compounds of this metal.
 this is the only one which is insoluble.
   This acid is easily obtained, by heating in a small re-
 tort a phosphuret of  iodine, containing 8 parts of iodine
 and 1  of phosphorus, moistening it slightly,  and mode-
 rately heating the  mixture.  The gas is collected in a
 flask of air; for  it dissolves in water, and is decomposed
 in mercury.   It  is composed of 100 parts of iodine, and
 0-783 of hydrogen ; or in  volume, half a volume of the
 vapour of iodine, and half a volume of hydrogen.  Gay-
 Lussac first  discovered the nature and properties of this
 acid.
   Acid Hydro-Chloric   Muriatic Acid Gas.   Colour-
 less, of a sharp odour, extinguishing combustion, having
 a density of 1-247.   It produces white vapours in the at-
 mosphere, by uniting with aqueous particles; potassium
 and  sodium  in   contact  with  it  are  transformed  into
 chlorides, and a quantity of hydrogen is  obtained equal
 in volume to the  part of the gas absorbed.   {Gay-Lussac
 and Thenard.)  It  is the same with iron, tin,  and man-
 ganese.   Water  dissolves of this acid, about 464 times
 its volume, at 68°, at the ordinary pressure of the  at-
 mosphere.  Water, thus  charged  with gas,   throws  it
 off in great quantities by heat.   It forms a white precipi-
 tate with the  nitrate of silver and solutions of lead; the
 precipitate which is obtained in the latter, is soluble in 50
 parts of distilled water, while that of the former is abso-
lutely insoluble.  It precipitates white with albumen, but
does not act upon gelatine.
  This  acid forms, with almost all  bases, combinations
which  are regarded  as chlorides (muriates)  or hydro-
chlorides.   (See these words.)   It is seldom found free
in nature, but forms many combinations.  It is for com-
merce obtained from the chloride of sodium (common salt.
                         5* 
o
 54                     A C I

 or muriate of soda,) by the aid of sulphuric acid.   This-
 decomposition is carried on in manufactories in cast iron
 cylinders; into these is introduced common salt,  diluted
 sulphuric acid is then poured upon it;  the gas is received
 in casks of water, the  last of which contains lime-water
 to absorb the gas which  is not dissolved.   The muriatic
 acid in a liquid state is the product of  this operation.  Ii
 may be obtained in  small quantities by a similar process.
 by using a matrass and fitting to it flasks of Woulfe's ap-
 paratus.   The first  flask serves  only to wash the gas.
 which always carries with it a small quantity of sulphuric
 acid.   To obtain the acid  very pure, it is necessary to
 distil it a second time ; and the better to disengage the gas.
 in order to separate it anew, to put into the vessel which
 is used for the operation  some grains  of zinc or tin.  It
 was  long supposed  that  this acid was  a compound  ot
 oxygen and an unknown base, but the brilliant expert
 ments of Gay-Lussac and  Thenard have demonstrated
 that powerful acids  may exist, of which oxygen forms no
 part.   This is composed of chlorine and hydrogen; one
 volume of each of these gases combined,  forms two vo-
 lumes of the hydrochloric acid.
  Acid Hydro-Chloro-Nitric.  Nitro.Muriatic.    Thi^
 mixture of hydro-chloric and nitric acidswas formerly cab
 led aqua regia. These two acids mutually decompose each
 other, and the result is water, chlorine, and nitrous acid.
 This acid is one of the most powerful solvents in chemistry;
 few bodies resisting  its action.  Among the metals are a
few exceptions, as chrome, titanium, columbium, rhodium,
iridium, and silver,  the last is however attacked by it.
 and changed into an insoluble chloride.   This acid is
 frequently employed in the  arts, and in chemistry.   It is
 always coloured by the nitrous acid which it contains.
  Acid Hydro-Cyanic.  Prussic Acid.  Liquid, colour-
 less, of an acid and corroding taste, its density at  45c
 is 0-70583, and  that of its vapour is 0-9476. It  red-
 den* litmus paper but feebly, its odour is strong,  and r 
A  C I
55
is very volatile; it boils at 79°. The Voltaic pile decom-
poses it, the hydrogen  is carried to the negative pole;
and the cyanogen to the positive pole.
  When a few drops of this acid are suffered to fall upon
paper, the portion  which vaporizes, produces  sufficient
cold to crystallize the remainder.  It is soluble in wa-
ter and alcohol,  is easily inflamed  by  the approach of a
burning substance.  Sulphur volatilized in the vapour of
this  acid, gives  rise to  a solid compound formed of cy-
anogen and sulphuretted hydrogen.  Chlorine disengages
its hydrogen, forming  chloro-cyanic  acid.  Potassium
and sodium set the hydrogen free, and  form cyanides.
  Hydro-cyanic  acid  precipitates  the nitrate  of silver
white.  United to potash and to the oxide of iron, it fur-
nishes a double salt of a lemon colour, 'which is  soluble in
water; in this solution,  a blue precipitate  is formed with
the salts of iron in the second and third degree of oxida-
tion, a brownish crimson  precipitate is formed with the
maximum salts of copper, a  blood  red precipitate with
the salts of uranium, and  an apple green with those of
nickel.   (Orfila.)
  According to Berzelius and Dulong, prussic or hydro
cyanic acid is in weight formed of 3-645  of hydrogen.
44-65 of carbon, and 51-705 of nitrogen, or in volume of
I of vapour of carbon, \ of hydrogen,  and i of nitrogen.
Scheele discovered this acid, but  Gay-Lussac first ob-
tained it in a state of purity, and investigated most of it<«
properties.   The following is  the  process which that
learned chemist has proposed for obtaining it pure.
  To a tubulated retort  is fitted an adopter containing one
half pounded limestone, and one half chloride muriate
of calcium.   From the adopter proceeds a tube which ie
placed  under a  bell-glass surrounded with a freezing
mixture.   Into  the  retort should previously have been
put cyanide of mercury; through the tubulature is poured
» quantity of muriatic acid so that it may be in  excess ot 
56
A  C I
 the cyanide.  A moderate heat in then applied, in order
 that the acid slowly evolving, may disengage itself from
 lhe muriatic acid and the water which it contains, while
 passing successively through  the carbonate of lime and
 the muriate of calcium contained in the  cylinder; the
 prussic acid is condensed in the receiver.
   Vauquelin has proposed another process for obtaining
 this acid.   Take three bottles  of Woulfe's apparatus ; in
 the first put a sulphuret of iron, and an S tube in order
 to introduce the  sulphuric acid. ■  In the second bottle, is
 put water to  wash the  sulphuretted  hydrogen which is
 disengaged, and the  third is three fourths  filled  with ;i
 solution of 1 part cyanide of mercury in 8 parts distilled
 water.  The apparatus  is terminated by a tube for  the
 escape of the evolving  gas.   In the first bottle is then
 poured diluted sulphuric acid.  The water is decomposed  :
 an oxide  of iron, then a  sulphate of iron is formed; the
 hydro-sulphuric  acid  unites  with  the solution  of  the
 cyanide, forming the  hydro-cyanic acid and the sulphate
of mercury.  When the sulphuretted hydrogen  is in
 excess, the  liquid is  filtered in order to separate from il
the black  sulphuret of mercury.  A solution of  hydro-
 cyanic and sulphuretted hydrogen is obtained.   To  this
 solution is then added the carbonate of lead, which de-
composes  the sulphuretted hydrogen; after some days
the solution is filtered and hydro-cyanic acid obtained at
0-900 of density.  As this  acts with extreme violence
upon  animal matter, all  possible precaution should be
used in its preparation and use.
   Acid  Hydro-Febro-Cyanic.  Ferro-Prussic  Acid.
 According  to the researches of Gay-Lussac, Robiquet.
and Porrett, it appears that iron and cyanogen can com-
bine in the proportions of 1 atom  of iron  and 3 atoms of
cyanogen, so as to form a new body which shall  be  the
radical of  this acid.   The  opinion  of these chemists
acquires still more  weight, if we consider that sulphur 
A  C 1
5?
and silver  can replace the iron  in  this compound,  and
form with hydrogen, acids which  Porrett has designated
under  the  names of ferruretted argenturetted, and  sul-
phuretted chyazic acids. (Those who wish to examine this
subject are referred  to the reports  of these chemists.)
This acid is in little white  crystals which become bluish
when  exposed  to  the   air;  they   are soluble  in
water  and in  alcohol, communicating  to  these  liquids
no colour,  but an acid taste unlike that of the common
hydro-cyanic, or prussic  acid.   The  aqueous  solution
poured upon  the  .tritoxide  of  iron produces the prussian
blue, which  is a hydro-ferro-cyanate  (prussiate) of the
peroxide of iron.
  Acid Hydro-Muriatic.   See Hydro-chloric acid.
  Acid Hvdro-Sulknic.   A colourless gas of an odour
similar to that of  sulphuretted  hydrogen; its action upon
the animal economy is most deleterious :  it is soluble in
water,  reddens litmus, and  stains  the skin brown.  It is
obtained by treating the selenue of iron, (spongy gypsum,)
with liquid muriatic acid.   It  was discovered and exam-
ined by Berzelius.
  Acid Hydro-Sulphuric.  Sulphuretted Hydrogen.  Is
a gas  of a very disagreeable odour;  it  is without colour,
and  burns in the  atmosphere with a bluish flame.   Its
specific gravity is 1-1912, it reddens  litmus but feebly, is
decomposed by a great numbej- of simple bodies ;  chlo-
rine  at the ordinary temperature precipitates its sulphur,
iodine  acts upon it in the same manner, especially if it be
in a humid state.   Most of the metals absorb the sulphur
and  set the  hydrogen free.  When heated  in  contact
with potassium and sodium, it  forms  a   compound which
results from the combinations  of the metal with the  sul-
phur and a certain quantity of sulphuretted hydrogen, a
portion of the hydrogen being  set free.   {Gay-Lussac  and
Thenard, Researches Physico-Chemical.)
  Hany acids decompose  sulphuretted  hydrogen at  the 
.I.S
A  C 1
 ordinary temperature ;  this is always done by abstracting
 the hydrogen.   Among the  acids that  have this effect.
 are the chloric, nitric, nitrous, sulphurous, and sulphuric.
 Water dissolves about three times its volume at 52.c
 and  at the ordinary pressure.   In  this state it precipi-
 tates the solution of the deutoxide of arsenic yellow, and
 the solutions of  lead, copper, and bismuth, black.   The
 eras which the  solution contains is eliminated by heat:
 this gas contains a volume  if hydrogen  equal to its own:
 it is composed in weight oi* 100 of  sulphur, and of 6-13
 of hydrogen.   It is prepared by .renting at a moderate
 heat the sulphuret  of iron  with diluted sulphuric acid,
 or the  sulphuret of avtiimony with muriatic acid.   It is
 necessary, while preparing  it,  to  avoid  respiration as
 much as  possible, for its properties are in a high degree
 poisonous, as is the  case with almost all  the  binary com-
 binations of hydrogen.
  Acid Hydro-Xanthic.  A name  proposed by Zeise.
 lo designate the combination  of hydrogen with sulphur
 and carbon, which combination he considered as a  pecu-
 liar acid.
  Acid Hypo-Nitrous.  {Hypo-Nitreux.)  Per-nitrous.
 Gay-Lussac named  thus, an acid composed of 100 of ni-
trogen and 150 of oxygen ;  it has never  yet been insula.
ted, for it is destroyed in the attempt  to  separate it from
the potash, the only  base with which it has yet been com-
bined.
  Acid Hypo-Phosphorous.   {Hypo-phospJwreux.)  Li
quid, uncrystallizable, very sapid, is easily decomposed b}
heat.   If the operation is carried on in a retort, phosphu-
retted hydrogen, from the phosphorous and the phosphoric
acid, is obtained.   It is very soluble in  water, and com-
municates this property to  all the salts which it forms.
 \ccording to Duiong, the  discoverer of this acid, it is
composed of 100 of phosphorus  and 37-44 of oxygen. 
A  C I
59
 It is obtained by dissolving the phosphuret of barium in
 water ; the result is a soluble  hypo-phosphite  of barytes,
 the base of which is precipitated by a suitable quantity
 of sulphuric acid.   The  liquor must then be filtered and
 concentrated by a careful evaporation.
   Acid Hypo-Phosphoric.   {Hypo-Phosphorique.)   Li-
 quid,  viscous, very sapid, having a slight odour of phos-
 phorus, decomposing by  heat and transforming itself into
 phosphoric  acid  and  phosphuretted hydrogen,  which
 inflames at the mouth of the vessel which contains  it.
 It decomposes rapidly in contaet with any salifiable base.
 becoming  phosphorous  and  phosphoric  acid;  from this
 circumstance Dulong has inferred that it is but a combi-
 nation of the two  acids.   It is obtained by slowly burn-
 ing sticks of phosphorus  in the damp air.   According to
 Thenard, this acid  is formed of 100 of phosphorus and
 110-39 of oxygen.
  Acid Hypo-Sulphurous.  {Hypo-Sulphureux.)  Com-
 posed of 100 of sulphur  and 50 of oxygen.
  Acid Hypo-Sulphuric.  {Hypo-Sulphurique.)   Com-
 posed of 100 of sulphur and  135 of oxygen.   Its disco-
 very,  and  the study of  its properties  are  due to Gay-
 Lussac and Welter. It is a colourless liquid, always re-
 taining a certain quantity of water.  When it contains the
 least possible quantity, its density is 1-347, and then it has
 commenced a decomposition into sulphurous and sulphu-
 ric acids-   It easily combines with salifiable bases.  It is
obtained by passing a current  of sulphurous acid gas into
water, which holds in suspension the peroxide of manga-
nese.   Exposed to cold it produces a neutral compound of
hypo-sulphate  and  sulphate of manganese.   This solu-
tion is  treated with powdered barytes ; it is heated, then
 filtered ; a current of carbonic acid gas is then passed into
it ;  after having been boiled it is again filtered.  The hy-
po-sulphate is  crystallized, re-dissolved, and the barytes
orecipitated by a careful addition of sulphuric acid. The 
60
A  C I
 acid is concentrated under the receiver of the pneumatn
 cistern.
   Acid  Igazurio.   {Igazurique.)   This acid  appears
 under the  form of little white needles, very  light,  very
 acid, and soluble in water and alcohol.  The igazurate of
 ammonia forms  with the sulphate  of copper, a fine green
 colour, and gives place to a granular  and crystalline pre-
 cipitate.   The knowledge of this acid is due to Pelletier
 and Caventon. It exists in St. Ignatius' bean,* the vomica
 nut,f and  probably in the  other species of the genus
 Strychnos.
   Acid  Iodous.   {Iodeux.)  Liquid,  of an  amber  yel-
 low, an oily consistence, of an  odour similar to that ol
 the oxide of chlorine ; it  reddens litmus, volatilizes at
 122°, is soluble  in water and alcohol.  Sulphuric acid de-
 composes it, and precipitates the iodine.   It is obtained
 by triturating a mixture of iodine and chlorate of potash,
 introducing the mixture into a retort, and heating it  with
 a  spirit  lamp.  The  iodous acid is disengaged in  the
 form of yellow vapours, which are condensed  in the re-
 ceiver ; oxygen  is also eliminated, and a small quantity of
 iodine is  volatilized.            •
   This acid was discovered and studied by Sementini.
   Acid Iodic.   {Iodique.)  Solid, inodorous, white, trans-
lucid ; changes  blue vegetable  colours  to red, and  then
destroys all colour.  Its density exceeds that of sulphu-
ric acid.  At a high temperature it is changed into iodine
and oxygen gas.   Most of the strong acids decompose it,
except the  sulphuric and phosphoric, which appear to
form combinations  with it; it detonates if heated  with
sulphur or carbon.  This acid is formed of 100 of iodine
and 31-927 of oxygen. The weight of an atom is 20-625.
It  is obtained by  treating  iodine  with the  protoxide of
chlorine.   It was discovered by Gay-Lussac.
* Strvchnos Ignatia.
fSTRvcHKOs JVnz vemict,'. 
A  C  I
Gl
  Acid Iodo-Sulphuric.   The  name  of a  crystalline
compound, of a pale yellow, which is obtained by pouring
sulphuric acid, drop by drop, into a hot  and concentrated
solution of iodic acid.   These little crystals  appear to
contain water ;  brought in contact with potash or soda,
they form an iodate and a sulphate.  Nitric and phospho-
ric  acids form with the iodic acid analogous compounds.
  Acid I atrophic  {Iatrophique.)  A name given by
Pelletier and Caventon to a liquid  acid, colourless, of a
very strong odour, very soluble in water, which they have
found in the oil of the jatropha plant.
  Acid Karabic  This is the Succinic acid.  (See this
word.)
  Acid Kinic   {Kinique.)   White,  solid,  crystalline.
very acid, strongly reddens litmus, has not a bitter taste ;
heat decomposes it, and produces pyro-kinic acid equally
crystallizable.   The kinic  acid has been found only in the
quinquina,  united to  lime  and  perhaps  also a  little qui-
nine and cinchonine.   It  is  extracted from the kinate of
lime by precipitating  the  base with oxalic acid.   It was
discovered  by Vauquelin.
  Acid Kinovic.   {Kinovique.)   A name given by Pel-
letier and  Caventon to an  acid which they found in the
heart of the kina nova, a tree  which grows  in  Africa.
It in some  respects resembles the oily acids ;  it is white,
light, flosculous, scarcely soluble in water, but very solu-
ble in ether and alcohol.
  Acid Krameric.   {Kramerique.)  Peschier  discovered
this acid in the  root of the ratania. After many attempts,
he  at  length  obtained it  crystallized  under the  form of
elongated prisms, of  a very styptic taste.  This  acid is
peculiar in having so great an affinity for  barytes as to
take it from sulphuric acid.
  Acid Laccic.   This has been discovered in stick lac ;
it is solid, crystalline, of a clear wine  yellow, of an acid
taste,  soluble in water, alcohol, and ether. It precipitates
                         6 
G2
A  C I
solutions of lead and mercury white ;  but it acts neither
upon lime, water, nor upon the nitrates of silver and ba-
rytes.   Alone, or in combination, it gives a white precipi-
tate  with the salts of the peroxides of iron.
  Acid Lactic   Its existence is still uncertain.  It may
be but the  acetic  acid  united to  a vegetable  matter, or
perhaps the same as the zumic acid.  Scheele discovered
it in  sour whey ; according to Berzelius, it exists also in
blood.   It is a thick liquid,  uncrystallizable,  soluble in
water and alcohol,  combining  with bases, and forming in
most cases  soluble salts.  It is  usually obtained  from
whey.
  Acid Lampic.   A name given  to the product which is
formed during the  contact of inflamed platina with the
vapour  of ether;  it appears to  be composed of acetic
acid, and a compound of hydrogen and carbon.
  Acid Loci stic.  (From locusta, in  French saulerelle.)
An acid said to be found in the locust, but not sufficiently
known to be distinguished from acetic acid.
  Acid Malic.  (From Malus, a genus of plants which
contains the apple.)   Liquid, colourless, crystallizable,
of a very acid taste ; is decomposed by heat, and among
other products  gives a peculiar acid, called  pyro-malic.
\itric  acid changes it to oxalic acid.   It does not act
upon the nitrates of lead and silver.  According to  Vau-
quelin, it is in weight composed of 28-3  of carbon, 54-9
of oxygen, and 16-8 of hydrogen.  It is the  same acid
which is sometimes known under the name of sorbic  acid.
It exists in the berries of the sorbus, (mountain ash,) in
apples,  gooseberries, and the  greater part of  acid  fruit,
and  the leaves  of  the semper vivum tectorum (house
leek.)   From the last named plant it is extracted by the
following process :   The juice of the house leek is sa-
turated by an excess of lime-water, about three quarters
of the liquor separated from  the excess  of lime is  then
evaporated ; this deposites, during the evaporation, the 
A  C 1                     63
sub-malate of lime, mixed with a colouring matter ;  the
mother  water is then separated, the  sediment is several
times washed with alcohol at about 54°, in order to divest
it of the principal part of the colouring matter ; it is then
treated  with water, which dissolves and changes the sub-
malate into a soluble malate and lime, the latter remain-
ing combined with a portion of colouring matter.
  The solution of the colourless malate of lime is treated
by the neutral  nitrate of lead;  it forms a precipitate of the
neutral  malate  of lead, which, being washed  and treated
by sulphuretted hydrogen, gives a colourless solution of
malic acid.   By evaporating this solution, a liquor of the
consistence of sirup is obtained; this, on standing a  few
days, deposites small whitish crystals.
  Acid Manganesic. The peroxide  of manganese when
fused with potassa, absorbs oxygen from the air and be-
comes manganesic acid.  This was discovered by Che-
villot and Edwards.  Dr. Forchhammer has obtained it
by the  action  of diluted  sulphuric acid  upon the man.
ganesite of barytes ; the manganeseous acid, when liberated
resolves itself into the deutoxide of manganese and man-
ganesic acid.
  Acid Margaritic. (From Margarita, a pearl.)  White.
insipid, inodorous, fusible at 140°,  insoluble  in water,
very soluble in alcohol and ether.  Most of the salts which
it forms have  a pearly appearance.  It reddens the tinc-
 ture of litmus,  and with heat   decomposes the   sub-
carbonates of potash and soda.   It  exists in the fat  of
dead bodies.   It is obtained  by treating pork grease  or
 human grease with potash.  According  to Chevreul,
this  acid is a hydrate, containing 3-52 of water, with 100
of dry acid; and  in a dry state it is formed of 8-937  of
 oxygen, 79-053 of carbon, and 12-010 of hydrogen.
  Acid Marine.   Hydro Chloric or Muriatic Acid.
   V( id Marine. Dephlogistic.   See Chlorine. 
GJ
V C  I
   Acid Mf.contc.   (So called  from Mekon,  the  Greek
 name of  poppy.)   Solid, white, crystallizes, sometimes
 with well defined crystals ; it melts and sublimes at 267°,
 is easily  dissolved in water  and  alcohol.   This solu-
 tion reddens litmus, and with the salts of iron possesses
 the peculiar property of changing its colour to a fine red,
 without producing any precipitate ; it acts upon the solu-
 tion of corrosive sublimate, and produces in the solution of
 the sulphate of copper, a deposite of pale yellow powder. It
 combines with alkalies, and produces soluble salts.   This
 acid was discovered in opium by Sertuerner, and we are
 indebted to Robiquet for the best method of preparing  it.
 For this  purpose  an infusion of opium should be  boiled
 with a certain quantity of magnesia,  and  the  deposite
 which is  formed, collected; this is the sub-meconate  of
 magnesia ; it is washed  and first treated with diluted al-
 cohol, then  with  concentrated  alcohol ; but the sub-
 meconate can never be  entirely deprived of its colouring
 matter.    Diluted sulphuric acid is then  poured upon the
 sub-meconate,  it is  heated, and a solution of the mu-
 riate of  barytes  is  added.  A precipitate  of meconate
 and of   sulphate   of barytes   is  formed.    The  pre-
 cipitate  is washed, and then with  heat  acted  upon by
 weak  sulphuric acid, which decomposes the meconate
 of barytes.  This  decomposition is less prompt  than it
 would be but for a  colouring  matter that hinders the
 action of the acid.  The residue is filtered and washed in
 a great quantity of water ; the liquors are united and sub-
 mitted to evaporation.   The meconic acid separates ; it is
 then washed in a little cold water, dried,  and sublimed
 with a gentle heat.
  Acid Mellitic.   Solid, may be  crystallized in little
 prisms or needles, of a sharp and bitter taste, soluble  in
water.   It forms  in  the  waters of lime,  barytes,  and
 strontian,  white precipitates soluble in nitric and hydro-
 chloric acids.   It precipitates the nitrate of copper  white, 
A  C I
65
 the nitrate of iron a reddish yellow, the acetate  of lead
 and the nitrate of mercury white.  It combines with pot-
 ash.   It exists combined with alumine,  in  the  mineral
 called mellite, or honey-stone.   It is obtained by treating
 the pulverized mineral with boiling water ; the water dis-
 solves the acid, and a small portion of the alumine ; the
 liquor is concentrated, and the alumine precipitated with
 alcohol.  It is then filtered  and carefully evaporated to
 dryness ;  a yellow mass ts now obtained, which  must  be
 purified  by several crystallizations.  Klaproth was the
 discoverer of this acid.
   Acid Menispermic  Extracted by Boullay, from the
 menispermum cocculus.   Among  its properties are those
 of not affecting lime-water, and of forming with barytes
 a soluble salt;  of precipitating  the  nitrate  of mercury
 gray, the  nitrate of silver a deep yellow, the muriate of
 tin yellow, the muriate of gold a reddish brown ;  of not
 acting upon the solution of proto-sulphate  of iron;  of
 forming in the solution of the deuto-sulphate of iron, a deep
 green precipitate ; of forming an abundant precipitate in
 the solution of the sulphate of magnesia, and  of not being
 changed into  oxalic acid, by nitric  acid,  h is obtained
 by treating  a strong  infusion of the nuts of the menis-
permum cocculus* with the nitrate of barytes ;  treating the
 precipitated  menispermate of barytes  with  alcohol,  in
 order to  carry off the colouring  matter, and  afterwards
 treating it with sulphuric acid,  to obtain the menispermic
 acid.
  Acid Mephitic.  See Carbonic Acid.
  Acid Molybdous.   Solid, white, soluble in water, sul-
phuric, hydro-chloric and nitric acids;  reddens the tinc-
ture  of litmus.  It is composed  of 100 of molybdenum,
and 34  of oxygen.   It  is obtained  by triturating  with
water a mixture of 1 part of molybdenum, and 2 parts of

              * A plant obtained from  the Levant
                         6* 
GG
A  C 1
molybdic  acid, and in boiling the  liquor, which gives a
blue precipitate.
  Acid Molybdic  White, solid, inodorous, little sapid,
very soluble, reddens the tincture of litmus.   Its specific
gravity is 3-46. It volatilizes at a certain temperature, but
if kept from contact with the air, it melts and crystallizes
in cooling.   Most of the  bodies which have a certain
affinity for oxygen, take from it a  portion of this  sub-
stance, and reduce it to the state of molybdous acid.  It
is formed of 100 of metal, and 50  of oxygen.  It exists
in molybdated lead; but  is  always obtained from  the
sulphuret  of molybdenum,  first  by  pulverizing  and
roasting, then heating it with a solution of potash ;  the
molybdate which is formed is  decomposed by sulphuric
acid, and the  molybdic acid is precipitated.
  Acid Moric or Moroxylic  This acid crystallizes in
very sharp needles of a yellowish  colour  and  an acid
taste.   It  reddens the tincture of litmus, and dissolves in
water  and alcohol.   If heated in  contact with  the air,
one portion is decomposed, and produces a gas in which
the other  portion  volatilizes, and condenses itself into
prismatic crystals.  It forms with  lime, a salt little  so-
luble.   This acid was discovered  by Klaproth.   It is
found combined with lime, forming little brown grains
on the bark  of the white  mulberry.  It is  obtained by
boiling this  bark in a large  quantity of distilled water.
This is evaporated, and the morate of lime  is obtained ;
this latter substance is boiled with an excess of the ace-
tate of lead, and the morate of lead which has been pro-
duced, is decomposed  by sulphuretted hydrogen.
  Acid Mucic.  (From mucus, it being generally obtained
from  gum.)  White,  pulverizable,  little sapid, scarcely
soluble, it feebly reddens  the tincture of litmus.  In its
decomposition by  heat, it yields a peculiar acid,  sus-
ceptible  of  crystallization.    According  to  Scheele,
who discovered this  acid, it  is soluble in  alcohol.— 
A  C I
6*
 It  precipitates  the  waters  of  lime,  barytes,  and
 strontian,  but  the  precipitate  is  dissolved  anew  in
 an  excess of acid.   It acts upon the nitrates of silver,
 and mercury,  also upon the acetate, the  nitrate and
 the hydro-chlorate of lead; but it does not act upon the
 salts of magnesia and alumine, upon the hydro-chlorate
 of tin and mercury, nor upon the sulphates of iron, zinc,
 manganese, and copper.  This acid is always a product
 of art.  It was first  obtained by heating the  sugar  of
 milk with  nitric acid ;  on this account it was called sac-
 cholaclic acid, but it is now known  to be afforded by all
 gums, and from thence is the term, mucic acid.   In ob-
 taining  it from  the  sugar of milk, three parts  of nitric
 acid are heated with  that substance ;  in the bottom  of
 the  retort  is  found  a white  powder, which  by washing
 may be rendered pure;  this is  the mucic  acid.  It is
, composed in weight of carbon, 33-69, of oxygen, 62-69,
 and hydrogen, 3-62.   {Gay.Lussac and Thenard.)   The
 results of Berzelius are a little different.
   Acid  Muriatic.  See Hydro-chloric Acid.*
   Acid  Phlogisticated Muriatic.   See Chlorine.
   Acid  Hyper-Oxygenated Muriatic.  See  Oxide of
 Chlorine.
   Acid Nanceic  See Zumic Acid.
   Acid Nitrous.  {Acide Nitreux.)   The physical cha-
 racters of this  acid are  very valuable and  curious.   It
 was for a long time considered as a gaseous body; but
 Dulong, who examined it with his ordinary sagacity, con-
 siders it as liquid at  the ordinary temperature of the
 atmosphere.  Its colour varies according to the degree of
 heat to which  it is exposed, from 59° to 83°.  It  is
 orange  coloured at 32°.   Its density is 1-451; it boils
 at 83°.  In  contact with oxygen  and the  vapour  of
 water,  it is changed into nitric  acid;  inflamed bodies
* They arc synonymous terms, and so used in this work, 
G8
A  C I
 which are immersed in it continue to burn.   It acts upon
 different bodies in much the same manner as nitric acid.
 If brought in contact with sulpuretted hydrogen, at the ordi -
 nary temperature, it precipitates the sulphur.  It forms,
 with concentrated sulphuric acid, a crystalline compound
 decomposable by water.   Nitrous acid is in volume com-
 posed of  1 of nitrogen and 2 of oxygen,  or in weight of
 100 of oxygen, and 44-25 of nitrogen.  It is obtained by
 heating in a  small retort, very dry neutral nitrate  of
 lead; the acid passes  over into a receiver surrounded
 with a cooling mixture.
  Nitric Acid.  This substance was discovered in 1825
 by  Raimond Hill,  who called it the spirit of nitre, be-
 cause  he had obtained it by heating a mixture of clay
 and the  salt of nitre,  (nitrate of potash.)   It contains
 always a certain quantity of water, without which it can-
 not exist.  According  to  Gay-Lussac, the  specific gra-
 vity of that which  contains  the least  water is 1-510 at
 65°.
  It is  a colourless liquid, with a peculiar odour, of a
taste extremely caustic, so much so, that  it  disorganizes
animal matter with which it comes in contact.  It red-
dens strongly the tincture of litmus.  It boils, according
to Theuard,  at  187°,  and  decomposes at a red heat.
The products of this decomposition are oxygen and wa-
ter.   It congeals at 60°  below zero, but never becomes
very solid.  When highly concentrated, it is decomposed
by the solar light as effectually as by red  heat.   Most
combustible bodies decompose nitric acid by  attracting its
oxygen ; the quantity of oxygen absorbed varies accord-
to the  affinity of the body for oxygen, and according to
the temperature under which the experiment is  made.
This nitric acid may be transformed into nitrous acid, the
deutoxide of nitrogen, the protoxide of nitrogen, and even
nitrogen.   Chlorine, iodine,  and nitrogen have no ac-
tion upon  nitric acid ; this is also the case with gold, pla- 
A  C I
G9
tinum, iridium, rhodium, osmium, columbium, cerium, tita-
nium, chromium, and tungsten.  All the other elements,
metallic and non-metallic, effect its decomposition at dif-
ferent temperatures.  In their contact with this substance,
metals pass to the state of an acid or an oxide, and in the
latter case, the  portion  of nitric  acid  not decomposed
almost  always unites  and forms a nitrate.   Antimony
and tin  are  exceptions to this rule.   In some cases  also,
the water of the nitric acid is decomposed, and hydrogen
in a state of gas, uniting with the  nitrogen from a part
of the nitric acid, combines and forms ammonia.  From
thence  the nitrate of ammonia, which is observed in the
solution of some metals in this acid.  Sulphuric acid, ab-
stracting the water which it  contains, transforms it into
oxygen  and nitrous acid.   It seems to possess the power
of dissolving a large quantity of the deutoxide  of nitro-
gen.  In this case is obtained a mixture of nitric acid, of
nitrous acid, of the deutoxide of nitrogen and of water.
This mixture  takes different colours according  to the
quantity of the deutoxide of nitrogen it  contains.
  Nitric acid attacks  almost all vegetable  substances
which do not act as salifiable bases; it  always  yields to
them a certain quantity of oxygen, often causing them to
pass into the state of acids.   Its action upon animal sub-
stances is also very energetic.  It usually decomposes
them, by decomposing itself, and gives rise  to many of
the compounds resulting from the union of oxygen, hy-
drogen, carbon, and nitrogen ; among the substances thus
produced  are  ammonia, hydro-cyanic acid, nitrous  acid,
malic, acetic,  oxalic, and carbonic  acids, and a peculiar
yellow and detonating compound, which is considered as
a combination of the hypo-nitrous  acid with an  animal
substance.
  Nitric acid  is composed of 1 volume  of nitrogen, and
2i volumes  of oxygen ; or in weight, of 35-12 of nitro-
gen, and  100 of oxygen.   The  weight of its atom is 
70
A  C I
6-75.  It has never been found free in nature.  It indeed
exists in  places continually exposed to the decomposition
of animal substances, or where substances containing it
are gradually decomposed; but it is always united to bases,
principally to lime, magnesia, and potash.   It was formerly
prepared by making a mixture of the nitrate of potash
and argillite.   This mixture was put into large  stone
retorts called mines;  to  these were adapted stone re-
ceivers, and these cuines  were placed under a long fur-
nace, called a galley-furnace; potash and alumine com-
bining, the acid was set free ; the residue was heated with
sulphuric acid in order to obtain alum.   But as sulphuric
acid is now furnished at a low price, it is  found  to  be
more advantageous to employ that for the decomposition
of the nitrate of potash;  this salt is introduced into cast
iron cylinders which communicate with stone receivers;
sulphuric acid  and argillite are  added  to  the nitrate of
potash.   The mixture is at first gently heated, the fire is
then increased until the  acid has ceased to come over.
The acid thus obtained is not pure : it is coloured yellow,
more or  less, by the deutoxide of nitrogen; it  also con-
tains a little of muriatic acid, and a small quantity of
sulphuric acid; this is abstracted by distilling it with a
small quantity of the nitrate  of potash;  it is  afterwards
heated in the open air, in order to disengage the  deut-
oxide of nitrogen,  and the muriatic  acid.   In order to
obtain the nitric acid in a pure state for  medicinal pur-
poses, add to the common acid the nitrate of barytes, un-
til it cease  to form any precipitate; then use with equal
care the nitrate  of silver; and for fear that a little of
these nitrates may be retained, the acid should be dis-
tilled anew ; it will then be perfectly pure.   This is one
of the acids in most common use.  It is known in  com-
merce under the name of aqua fortis, or strong water;
when diluted, it is  called single.  It  is  much used as a 
A  C  I
71
  ic-agent;  and in pharmacy, in order to prepare different
  salts, oxalic acid, oxygenated pomatum, &c.
    Acid  Nitro-Hydro-Chloric.    See  Acid  Hydro-
  Chloro-Nitric.
    Acid Nitro-Leucic.   Braconnot gives this name to
^ the combination of nitric acid  with leucine.  According
  to him, this is an acid different from  the nitro-saccharic
  acid, and susceptible  of uniting with bases.
    Acid Nitho-Muriatic   See Hydro-Chloro-Nitric*
    Acid Nitro-Saccharic  A name proposed by Bra-
  connot  to designate the combination which the nitric acid
  forms with a peculiar  crystalline matter  which results
  from the action of sulphuric  acid upon gelatine.   This
 acid is solid, crystallizes in prisms, is colourless and stri-
  ated,  fuses upon coals, forms with  lime a salt not deli-
 quescent ;  is little soluble in alcohol, and forms with the
 oxide  of lead a detonating  salt.   Thenard properly re-
 gards the mineral acid which enters into its composition
 as the hypo-nitrous acid.
   Acid  Oleic.   The discovery of this acid and  the study
 of its properties are  due to Chevreul.    It is liquid, co-
 lourless, of an oily consistence, a rancid odour and taste.
 Its specific gravity at  60°  is 0-898.  Heat decomposes
 it, except in a vacuum, where it volatilizes.   It  congeals
 at a little above 32°, and forms a crystalline mass.  Water
 does not dissolve it, but it dissolves in alcohol;  it unites
 to stearic  and margaritic  acids, and  it decomposes  the
 sub-carbonates.   It exists in the  fat of dead  bodies;  is
 obtained by treating  pork  grease Avith potash.   It con-
 tains 3-95 of water to  100 of dry acid.   In the dry state

  * In most English books of chemistry, the term Nitro-Muriatic is used  to
 designate this substance, which is the Aqua Rcgia of the ancients.  But, ac-
 cording to  the  present commonly received theory of chlorine, the term kydro-
  hloro-nitric is most correct, as designating its compounds.  Yet the terms mu-
 riatic acid, muriates, &c., are already so firmly established by custom, that they
 will still continue to be used, notwithstanding their imperfect signification ; it
 is however important that the chemical student should be familiar with the new
 nomenclature founded on the chloridic theory. 
72
A  C I
it is in weight composed of 7-69 of oxygen, 80-94 of car-
bon, and 11 -35 of hydrogen.
  Acid Oxalic.   White, solid, crystallizes in small fine
prisms with four faces  terminated  by dihedral summits.
Its taste is very strong, it deeply reddens the tincture of
litmus.   Heated in a retort it fuses in its water of crys-
tallization ; afterwards one part is decomposed, the other
volatilizes and condenses in the neck of the retort.  Sub-
mitted to a red heat, without being in contact with the
air, it leaves no residue of charcoal.   It is soluble in two
parts of cold water, dissolves less easily in  alcohol.  Its
affinity for lime is such, that it takes it from sulphuric
acid.   The oxalate which is thus formed is insoluble in
an  excess of oxalic  acid.   Modern  chemists  are not
agreed as to the composition of this acid.   MM. Gay-
Lussac and Thenard consider  it as found in weight of
carbon 26-566, oxygen 70-589, hydrogen 2-745.  Berze-
lius found it in weight, composed of carbon  33-35, of
oxygen 66-41, or in volume of 2 of vapour of carbon and
3 of oxygen.   M. Dulong considers it  as composed of
carbonic acid and  hydrogen, and M. Dobereiner  sup-
poses it to be produced by a combination of one volume
of carbonic acid  with  one volume of the  oxide of carbon
and  one  proportion  of  water.   It  is  never  found in
nature but in combination with potash  and lime.  The
first of these combinations exists in the Oxalis Acetosella,
(wood sorrel,) the second in the root of the rhubarb.
  The oxalic acid is  in chemistry employed  as a re-
agent, and in the arts it is used to remove colours whose
bases are iron.  The  oxalic acid is obtained by treating
in  a retort sugar or starch with nitric acid.  These sub-
stances are not usually transformed into oxalic acid at
the first operation, unless nitric acid be in excess.  The
malic and acetic acids are obtained, and these are trans-
formed into oxalic  acid, by treating them with  a new
quantity of nitric  acid.  At first very large crystals are 
A  C i
73
obtained, but as the crystallization is successively repeat-
ed, they are deprived of the nitric acid which they  con-
tain, and  appear under  the  form  of prisms, more and
more delicate.   This acid is also obtained by decompos-
ing the oxalate of lead by  sulphuretted hydrogen, filter-
ing and evaporating the liquor; on cooling,  the crystals
are deposited.
   Acid Per-Nitsous.   See Hypo-Nitrous Acid.
   Acid Phocenic.   This acid results from the action of
the alkalies upon phocenine.  It  is a colourless liquid.
having a strong odour;  it boils  at 212°, remains liquid
at 16°.   It volatilizes with water without being decom-
posed,  but is decomposed if distilled pure.  It resembles
the volatile oils in some of its characters ;  like them it is
 nflamed by the approach of an ignited body ; it scarcely
dissolves in water,  but  is readily  dissolved in alcohol.
Chevreul, to whom we are indebted for the discovery of
this acid, found it, though in  small quantitie-s, in  the oil
of the dolphin and the porpoise, also in the berries of the
snow-ball, {viburnum opulus.)  The phocenic acid  con-
tains 9-89 parts of water to  100 of dry acid, or on a mi-
nute analysis is found to contain in weight, carbon 66-370,
oxygen 26-030, hydrogen 7-580.
   Acid Phosphatic.  Dulong and some other chemists
name thus the acid already described under the head of
hypo-phosphoric acid.   This acid  was often described
under  the name of phosphorous  acid, when of the  four
combinations of phosphorus  with  oxygen, this and the
sulphuric alone had been discovered.
   Acid Phosphorous.   Liquid, colourless, inodorous,
very acid, very soluble in water, decomposable  by heat,
and capable of  forming with  bases,  salts which differ
essentially from the phosphates and the hypo-phosphates;.
 Dulong considers it as formed of 100  of phosphorus and
 74-88  of oxygen.   The weight of its atom is 4-67.  Tijis
acid is not used in the arts.   .It was discovered by Davy.
                         1  7 
74
A  C I
 Phosphorous acid is obtained by treating the proto-chlo
 ride of phosphorus with water.   It is sufficient to evapo-
 rate the water in order to obtain it pure.
   Acid Phosphoric.   This acid is white, solid,  colour-
 less, inodorous, heavieT than water, at red heat it melts
 into colourless glass ; at this temperature it is  decom-
 posed by  carbon,  potassium, sodium,  iron, zinc,  tin,
 and some other metals.   The products which are obtain-
 ed vary according to the quantity  of metal  in  relation
 to that of phosphoric acid.  It  acts upon  silver  in con-
 tact with the atmosphere but at an elevated temperature.
 Chemists are not agreed with respect to the composition
 of this acid.   We consider it with Dulong as formed of
 100 of phosphorus and  124-80 of oxygen.   Its uses are
 not numerous.   It is employed  in some analyses.  It is
 obtained by burning a piece of phosphorus under a bell-
 glass, upon mercury, in oxygen, or in atmospheric air.
 The acid which is formed is in flakes  resembling snow.
 It is usually prepared by placing upon a sand-bath a tu-
 bulated retort furnished with an adapter and a spherical
 receiver  terminated by two flasks of Woulfe's apparatus.
 Sometimes the two flasks are not added,  and they are
 dispensed with by luting the joints.  Into the retort is
 put eight parts of nitric acid ; this being made to  boil.
 one  part of phosphorus cut into small pieces is  added.
 When part of the  liquid is distilled, the apparatus is left
to cool, the distilled product poured into a retort, and the
 operation  continued until the gas ceases to be evolved.
The liquid in the retort is put into a pl'atina crucible where
it is heated until  it become vitrified.  Phosphoric  acid
 is also procured by decomposing the phosphate of ammo-
 nia by heat, or the phosphate of barytes  by sulphuric
 acid.  Phosphoric acid  does not exist free in nature, but
 i't makes part of the bones of animals, and  is found com>
 bined with  several different oxide's. 
A  C I
75
   Void Prussic.  See Hydro-cyanic Acid.  The combi-
nation of this acid with iron was long known  and used
as a pigment, by the name of Prussian blue, before its
nature was understood.
   Acid Prussic Oxygenated.  See Chloro-cyanic Acid.
   Acid Pseudo-Kinic   Scarcely known.   Discovered
by Vauquelin, in the bark of the Strychnos pseudo-kina.
   Acid Pyro-Acetic  See Pyro-acetic spirit.
   Acid Pyro-Ligneous.   See Acetic Acid.
   Acid Pyho-Citric.  It is  one of the products of the
decomposition of citric acid.  It is solid, white, inodorous,
very soluble  in water and  alcohol ; it reddens the tinc-
ture of  litmus,  and is peculiar in acting upon no metallic
solutions,  except the acetate of lead, and  the protoni-
trate of mercury.  According to M. Lassaigne, to whom
we owe its discovery, it is composed  of*47-5 of carbon,
43-5 of oxygen, and 9 of hydrogen.
   Acid Pyro-Malic.   This is one of the products of the
action of heat  upon  malic acid.  It is solid, capable of
crystallizing, fuses at 47-5,  and crystallizes in cooling.
It is soluble in ten parts of water,  and  dissolves much
more easily in rectified alcohol.  It combines with salifia-
ble bases and forms  peculiar salts.
   Acid Pvro-Mucic.   This  is  one of the  products of
the  distillation of mucic acid.  It  is  white, inodorous,
very sapid,  fuses at 298°,  volatilizes with a little  more
heat, and on cooling condenses into a crystalline mass.
It is soluble in twenty-six parts of cold water.   Alcohol
and warm water dissolve it  more readily.   It does not
precipitate the acetate of lead.  M. Houton-Labillardiere,
the discoverer, regards  it as formed of 52-118 of carbon,
45-806 of oxygen, and 2-111 of hydrogen.
   Acid Pyro-Tartaric.   It is obtained by distilling tar-
taric acid.   Like the preceding acid, it is  found in the
liquid  products of distillation.  It  is white, crystalline.
very sapid, fuses if exposed to heat in a  close vessel. 
76
A  C I
partly decomposes at a temperature a little more elevated,
is easily dissolved in water, crystallizes by evaporation,
and combines with different salifiable bases.
  Acid Rheumic  An acid found in  the stems of the
rhubarb, {Rlieum tartaricum.)   This is the oxalic acid.
  Acid Saccharine.   The  same as  the  oxalie  acid.
(See this word.)
  Acid Saccho-Lacttc.  See Mucic Acid.
  Acid Sebacic.  Its discovery and  the  study of its
properties are due to M. Thenard.  It is one of the pro-
ducts of the distillation of fat.  It is inodorous, little sapid,
heavier than water, and susceptible of  crystallization in
small white  needles.   Heat  at first fuses and then  de-
composes  it.  It is very soluble in warm water, and little
so in cold water; boiling water which  is saturated with
it takes a  massy form on cooling.  It is soluble in alcohol,
combines  readily with  the alkalies, and forms with them
neutral and soluble salts.  It does not contain nitrogen.
  Acid Selenic.  Solid, white,  crystalline, inodorous,
very sapid, strongly reddens the tincture of litmus.  Heat
volatilizes without decomposing it.  It attracts  moisture
from the air, is easily dissolved in water and  in  alcohol.
Many combustible bodies  decompose  it by the  aid of
heat.   According to Berzelius, it  is composed of 100 of
selenium  and of 40-33 of oxygen.   It is analogous to
phosphoric acid, in being obtained by burning  its  base,
selenium, in oxygen, or in treating it with nitric  acid. Ii
is not known to be of use.
  Acid Sorbic.   See Malic Acid.
  Acid Stearic.  Solid, white, inodorous, insipid, lighter
than water,  fuses at 104°,  and in this  state reddens the
tincture of litmus ; it crystallizes on cooling ; it is inso-
luble in water, but very soluble in alcohol;  nitric acid
decomposes it ; it burns like wax, when heated in con-
tact with  the  air.  In its properties  it  resembles mar.
garitic  acid.  It is never found  in  nature, but is ob. 
A  C I                     77
tamed by saponifying  fat.   In  100 parts it  contains
3*52 of water; abstracting the water, it is found to con-
sist of 7-377 of oxygen, of 80-154 of carbon, and 12-478
of hydrogen.   (For  further  particulars, see  chemical
researches of M. Chevreul upon fat.)
  Acid Stannic.   See Oxide of Tin, {Per.)
  Acid Suberic. It is obtained from cork {Quercussuber)
by nitric  acid.  It  is white, pulverulent, scarcely pos-
sessing the character of an  acid; it  however  forms
combinations  with  the alkalies.   It soon  fuses on ex-
posure to  heat, and then volatilizes ;  it is scarcely soluble
in water,  is more  so  in alcohol;  it neither precipitates
the sulphate of copper  nor that of  zinc.  According to
M. Bussy, it is composed of 58-30 of carbon, 34 of oxy-
gen, and 7-67  of hydrogen.
  Acid Succinic.  Solid, susceptible of crystallization
in flattened prisms,  is  without colour, of a sour taste.   It
is little soluble in water;  heat  decomposes one part, in
which  the other part vaporizes ;  it precipitates the per-
oxidated salts of iron, does not precipitate those of the
protoxide  of manganese.   According to Berzelius, it is in
weight  composed  of  47-888  of oxygen and 4-512  of
hydrogen.  It is found  in amber  and turpentine.  It is
employed in medicine.   Succinic acid is generally ex-
tracted from  amber, {succin.)  For this purpose, a cer-
tain quantity of amber is introduced into a  stone retort,
to which  is fitted an  adopter and a receiver terminated
by a tube.  It is gradually heated until  the  acid ceases
to be disengaged, the receiver  being cooled from time to
time.  One part of the acid volatilizes, and attaches itself
to the sides of the vessels; this is  the purest.  The other
is found in a liquid state, mixed with an oil of disagreeable
odour. The oil is separated and the liquor evaporated as
much as  possible by  a current of cold  air.   Crystals  of
the acid are obtained, then re-united to the part which is
volatilized ; they are combined with soda :  and thus  k 
78
A  C I
formed a soluble salt, which is decomposed by the nitrate
of lead.   Before adding the nitrate of lead, the liquor
should be treated with charcoal.   Lastly, the succinate
of lead is decomposed by sulphuric acid, and the succinic
acid is obtained very pure.
  Acid Sulpho-Cyanic.  This acid  is sometimes called
sulphuretted chyazic acid.   It is a transparent, colourless
liquid, reddens litmus paper, and combines with alkalies,
forming neutral compounds.
  Acid  Sulpho-Napthalic.   This acid results from the
combination of sulphuric acid and napthaline.
  Acid  Sulpho-Vinic.  An acid of but little importance,
generated during the process of preparing sulphuric ether.
  Acid  Sulphuric.  Oil of Vitriol. Its discovery, which
is dated from the fifteenth  century, is due to Basil Valen-
tine, who obtained  it  by distilling green copperas, (sul-
phate of iron.)  It  is a  colourless liquid, without odour,
of an oily appearance, of  a taste  extremely caustic, and
of course  strongly reddens  the  tincture of litmus,  h
usually contains one fifth of its weight of water, and in
this  state its density according to Thenard is 1-842.  It
congeals at —12° when concentrated, and at 32° when
diluted  «rith  water.   Exposed  to the  action  of  fire
it volatilizes without being decomposed ; if however the
temperature  is  very  elevated, it will  change  into 2
volumes of sulphuric acid and 1 volume of oxygen.  It
attracts so much humidity from the air as to double  its
weight.   A great number of combustible  bodies decom-
pose it at temperatures  more or  less  elevated.   It then
yields a part or the whole of its oxygen ; and the sulphur
is differently  affected  according to  the  nature  of the
decomposing substances.   The water which  it  contains
is also often decomposed.  Like nitric  acid, there are
few metals (and these are the same in both cases) which
are not  acted upon  by it. It attacks vegetable and animal
substances, and charcoal,  disengaging sulphuroas acid. 
A  C I
79
it produces in its mixture with water a great elimination
of caloric, owing to the condensation of the mixture;
while 1 part of acid and 4 of pounded ice or snow produce
a considerable  degree of cold, which cold is owing  to
the sudden liquefaction of the ice or snow.  This acid is
formed of 2 volumes of sulphurous acid, and 1 volume of
oxygen ; or in  weight  of 100 sulphur, and 150 oxygen,
(abstracting the water which it contained.)  The weight
of its atom is 5.
  The existence of sulphuric acid free, in nature, is still
doubtful.  Humboldt discovered in America waters  that
owed their acidity to it.  It has been said to  have been
found in a solid state in some grottoes, but it  was proba-
bly in the state of an acid sulphate of lime.  It is in many
countries an important branch of manufacture.  A  mixture
of 8 parts of sulphur, and 1 part of nitrate of potash, are
heated in a large capsule, placed in a capacious chamber
of lead.   The  floor of this chamber being covered with
water, every thing is ready for  the preparation of the
acid.   The sulphur and the saltpetre are inflamed and
burned.  When the combustion is finished, the sulphate
of potash which remains in the capsule is withdrawn, and
replaced by a new mixture  of saltpetre and sulphur.  The
air in the chamber is renewed by opening the door and
valve ;  these openings being closed,  the mixture is again
inflamed,  and  this operation is necessarily  performed
until the acid is at 40° of Baume's areometer ;* it is then
drawn from the chamber by means of a syphon, which is
conducted into a large kettle of lead, in which the acid is
heated until it marks 55° upon the areometer; it is then
put into earthen and platina vessels which are used in-
stead of retorts;  the acid is then heated until it marks 66°
upon the areometer;  in this state it is used in  commerce.
Although by some  of  the  last operations the sulphuric
* Commonly called hydrometer 
so
A  C I
 acid was separated from different substances, which ren-
 dered it impure, such as a large quantity of water, sul-
 phurous acid, and a small quantity of nitrous acid ; it still
 retains some sulphate of lead, and sometimes organic car-
 bonated matter.   By distilling,  it is obtained very pure.
 but the precaution must be taken to put into the retort
 some pieces of glass  or  porcelain, and some plates of
 platina; these serve to conduct caloric, and to establish
 an equilibrium between the layers of the acid.
   It is evident that in burning a mixture of sulphur and
 nitrate of potash,  sulphurous and nitrous acids  are pro-
 duced, or at least the deutoxide  of nitrogen, which by its
 contact with the oxygen of the air becomes nitrous acid.
 These two acids, which when dry have no action upon
 each other, present when humid remarkable phenomena.
 One portion  of nitrous acid  is decomposed,  and  yields
 oxygen to the sulphurous acid, which, passing into the
 state of sulphuric acid, combines with a small quantity of
 water and nitrous acid, and gives a deposite of little white
 crystals.  Water dissolves the sulphuric acid contained
 in the crystals, and the nitrous acid  appears in the form
 of yellow vapour.  The potash which was obtained from
 the decomposition of the nitrate of potash, combines with
 a portion of sulphuric acid and forms a sulphate.   It has
 been seen that it  was only necessary to introduce into
the leaden chamber the sulphurous gas, and the deutox-
ide of nitrogen,  with atmospheric air  to supply another
portion of oxygen ; we may arrive at the same result,  by
burning sulphur only in the leaden chamber, and pro.
curing the deutoxide of nitrogen, by  the  action of nitric
acid upon starch.  On account of the oxalic acid which
is the result of the latter process, this, in certain cases, is
more economical than the former. The uses of sulphuric
acid are very numerous ; it is employed as a re-agent to
detect barytes, and to prepare sulphuric ether, nitric acid.
muriatic acid, &c. 
A  C I
8i
  Acid Sulphuric of Nordhausen.  Although the his-
tory of this acid belongs to that of sulphuric acid, it may
deserve a separate notice.  According to M. Bussy it is
a brown liquid, which is chiefly prepared at Nordhausen,
by distilling the sulphate of iron, united to a small quan-
tity of the nitrate of potash.   It may also be obtained by
the distillation of such sulphates as can be decomposed by
heat.  By slowly heating this acid, a crystalline mass is
extracted, which is the anhydrous sulphuric acid. In this
state,  a little  below 77° , it is white,  opaque, absorbs
humidity from  the air, fuses even at the  temperature of
77°, and  forms a liquid, whose density is 1-57.  It dis-
solves sulphur, and this solution  may  be either brown,
green, or  blue.  It also dissolves indigo, forming a solu-
tion of a beautiful  purple colour.   The sulphuric acid of
Nordhausen is a solution of sulphurous acid and ordinary
sulphuric acid.
  Acid Sulphurous.   {Acide  Sulphureux.)  A colour-
less gas, of a strong and pungent  odour, at first redden-
ing the tincture of litmus, and then destroying  it.  Ac-
cording to Thenard, its density is 2-234.  Heat  alone
can  decompose it.   When moist, a cold of —58c
does not liquefy it;  but M. Bussy,  who made very inter-
esting observations  upon  this  acid, liquefied  it at the
ordinary pressure,  by  immersing it in  a refrigerating
mixture composed of two parts of  ice and one of common
salt;  the gas in this operation must be very dry.  When
liquefied,  it is a  colourless,  transparent liquid, whose
density is 1-45.  It produces so  much cold in  vaporizing,
as to induce the belief that it might be liquefied in this
manner;  and, by employing a certain pressure, this has
been accomplished.   Sulphurous acid gas does not com-
bine with oxygen at  any temperature;  but it may  be
decomposed at different temperatures, (never  by cold,)
by different combustible bodies, which absorb its oxygen;
it  also forms  combinations with sulphur.  Sulphuretted 
82
A  C I
hydrogen  decomposes  it  by decomposing  itself;  water
and sulphur are the result;  this decomposition will be
instantaneous, if the gases are not very dry.   Water, at
the ordinary  pressure of the  atmosphere and at 68°,
dissolves 37 times its volume.   Sulphurous acid contains
a volume  of oxygen equal  to  itself in weight; it is,
according to Berzelius, composed of 100 of sulphur  and
99-44 of oxygen.   This is chiefly used in medicine in the
treatment  of cutaneous diseases; and as for this use  it is
not injured  by a  mixture of atmospheric air, it may be
procured  by burning sulphur upon a chafing dish.  It is
prepared in  this manner for the bleaching of silk ;  but in
order to obtain it pure, it is necessary to treat a vegetable
substance, wood for example, with concentrated  sulphuric
acid; mercury may be substituted  for wood; the  sul-
phuric acid, yielding part  of its oxygen, is reduced to the
state of sulphurous  acid.
   Acid Tartaric.  {Acide  Tartrique.)  Solid, colour-
less, inodorous, crystallizable, of a  strong  acid taste.
Heat decomposes it, and  in its decomposition, it  gives,
among other products, a  peculiar  acid.  (See  pyro-tar-
taric acid.)   But if this experiment is made in contact
with the atmosphere, the acid inflames, and  produces
water and carbonic acid.   It  is very soluble  in water,
much less so in alcohol; nitric acid changes it into oxalic
acid.   It  precipitates the  waters of lime, barytes, stron-
tian, and the acetate of iead.   These  tartrates are solu-
ble in an  excess of acid; this is not the case with  the
precipitates which it forms in the concentrated solutions
of potash, soda, and ammonia.  According to the experi-
ments of M. Soubeireau, tartaric acid mixed with boracic
acid and put in a damp place, absorbs a certain quantity of
water, and liquefies, from  whence he concludes that there
can be a combination between them, but that their affinity
is very feeble.  According to MM. Gay-Lussac and The-
nard, tartaric acid is in weight composed of carbon 24-050. 
A  C I
83
 »xygen 69-321, hydrogen 6-629.   It  has not yet been
 found  pure in nature, but always in combination with
 lime and potash.   From this last combination it is usuall}
 extracted.  For this purpose let the acid tartrate of pot-
 ash be in a fine powder, dissolvei t in 15 or 20 parts of boil-
 ing water, and saturate the excess of acid  by a sufficient
 quantity of powdered  chalk (carbonate of lime,); filter
 the liquor, and  wash  the tartrate of lime which is thus
 obtained : into the filtered liquor pour  a solution of  the
 chloride of lime ;  there will be a double decomposition,
 tmd a  new deposite of tartrate of lime : the  substances
 obtained  should  be re-united as above, and treated b\
 three  fifths  of their weight of  concentrated sulphuric
 acid, diluted with  a great quantity of water, because  the
 sulphate of lime which is formed, solidifies a great pro-
 portion.   If the tartrate of lime be not well washed, it is
 easily perceived by the vapours of muriatic  acid gas which
 are disengaged. After the contact of the sulphuric acid has
 been prolonged seven or eight  days, water is  added,  the
 whole  shaken together, and left  to settle ; it  is then  de-
 canted, the residuum  washed,  the liquors  re-united and
 evaporated ; they  are  boiled for a moment with  a small
 quantity of animal charcoal,  again  decanted, and the
 acid left to crystallize.   Care must be taken not to use
 too much  of  the animal charcoal, for this, always con-
 taining phosphate  of lime, would present to  the  sulphu-
 ric acid a new occasion to exercise the force with which
 it acts  upon most salts.  It would set at liberty the phos-
 phoric  acid, and would oppose the crystallization of the
 vegetable acid.   In order to  obtain the acid perfectly
 pure it is necessary to boil it with litharge (the protoxide
 of lead,)  to filter  it, to pass it into a current of  sulphu-
 reted hydrogen, to filter it again, and to drive off by heat
 the sulphuretted  hydrogen which might remain.  The
tartaric acid is used in  medicine. 
84
V DI
  Acid Tungstic.   Solid, yellow, inodorous,  insipid;
when brought in contact with  deoxygenating bodies  at
an elevated temperature, it yields a portion of its oxygen,
and passes to the state of a deutoxide and even a protoxide.
It forms soluble salts with  soda, potash, and ammonia.   It
is composed of 100 of metal, and 25 of oxygen.   It has
no use.   It is extracted from the mineral called wolfram,
(tungstate of iron and manganese,) by heating  it with
muriatic acid, which dissolves the oxides of  iron and
manganese, but does not act upon the tungstic acid.
  Acid Vegeto-Sulphuric.   M.  Braconnot  propose?
this  name  for  a  combination  of sulphuric  or hypo-
sulphuric  acid  with a vegetable substance.   This acid
is obtained by treating woody  fibre, (ligneux.) with sul-
phuric acid.
  Acid Zumic   (From  Zume, yeast.)  This acid, the
existence  of  which  has been considered doubtful, was
discovered by M. Braconnot, in different vegetable sub-
stances, which had passed through the acid fermentation.
According to  this chemist, it is an uncrystallizable liquor,
almost colourless, and of a very acid  taste.   Heat de-
composes  it.   It  furnishes carbon  and acetic acid, and
forms soluble salts with the greater part of the salifiable
bases.   This acid is obtained by evaporating with a slow
heat the soured juice of the red beet.  When  nearly
soluble, it is treated with alcohol;  the  solution is filtered
and  evaporated  to  the consistence of sirup;  this  is
diluted with water, saturated with the carbonate of zinc.,
and  filtered;  the zumate  of zinc  is crystallized,  redis-
solved, and decomposed by barytes; the zumate of ba-
rytes is in its turn decomposed by sulphuric acid.
  Acier.   See Steel.
  Adipocire.  (From adeps, fat, and cera, wax.)   A pe-
culiar  fat-like substance,  formed  by  the spontaneous
change of animal matter,  in certain situations.  See /"«/
of dead bodies. 
A  I  R
85
   Adopter.   {Alonge.)  A tube usually of glass, which
 -erves to place the receiver at a greater distance from the
 distilling vessel.
   Affinity.  See Attraction.
   Air Atmospheric.   The  atmosphere envelopes the
 globe to an extent  not  exactly known.  It is  generally
 supposed to be about forty-five miles in height;  surround-
 ing  the surface of the  earth, it necessarily contains all
 the  gaseous substances which pass  off from it,  and all of
 the  new combinations, which the elements that compose
 this atmospheric air are capable  of forming.   It was,
 however, for a long  time regarded as a simple body, and
 ranked as one  of the four elements which formed all the
 combinations in nature.  This opinion, formerly received
 by all the learned, was not entirely destroyed but by the
 experiments of Lavoisier, although John Rey, more than
 a century earlier, had attempted to show its fallacy.   La-
 voisier proved by experiments that the air was composed
 of two gases, which possessed properties very different,
 and  whose proportions he attempted  to determine.  Al-
 though not very exact, yet his experiments  threw much
 V'ght upon the  subject.  According to the more  precise
 experiments  of modern chemists, the atmospheric air is
 formed of 21 of oxygen gas, and 79 of nitrogen ; it also
 contains a variable quantity  of aqueous vapour, and  one
 thousandth part  carbonic acid.  Other gases  which it
 may contain  enter so readily into combinations  with it,
 that  they are not to be found in the atmospheric air, but
 near the places where they are produced;  the quantity
 of other gases  being very small in proportion  to the
 whole mass of  the atmosphere, and the mixture of gases
 even of different densities taking place with facility, they
 are so disseminated as not to be easily detected by ana-
 lysis.  Carbonic acid is the only gas which is to be found
 in any considerable quantity in the atmosphere ;  the com-
bustion of vegetable substances, and  the respiration of
                          8 
86
A  I  R
 animals, continually furnish it in proportions sufficiently
 great to affect the purity of the air ;  but it is immediately
 decomposed by vegetables, which, appropriating to them-
 selves the carbonic acid of the  atmosphere, disengage
 almost all the oxygen which it  contains.   In countries
 where a low temperature, during  a part of the year, pre-
 vents the developement of most kinds of vegetation, the
 winds which  agitate  the atmosphere, and  the many
 mosses and resinous evergreens maintain  a continual
 equilibrium  in the proportion of carbonic acid diffused
 through the atmosphere.
   Atmospheric air is a colourless gas, inodorous, but sus-
 ceptible of transmitting odours: it is compressible, and
 ponderable.  Its specific gravity at 60°, and  the barome-
 ter at  30 inches, is usually considered as = 1 ; its den-
 sity being taken as  a unit in estimating the density of
 the gases.   It is about 828-59 times as light as its bulk
 of water ; 100 cubical inches weighing 30-5 grains.   Its
 chemical properties  are  somewhat  similar  to those  of
 oxygen.  Almost all combustible  bodies can  decompose
 it  at various temperatures.  It  is  always  the oxygen
 which it contains that is absorbed.  Many bodies absorb
 humidity from the atmosphere, the  alkalies  attract the
 carbonic acid which it contains, and on long exposure to
 it, become sub-carbonates.  Its uses are very numerous,
since it is essential to respiration and  combustion, and it
yields oxygen to many substances in chemical operations.
The natural currents which it forms are employed as a
moving force, as also its property of  being compressed.
 and of being dilated  by heat.
  Air Dephlogistic.  The same as Oxygen.
  Air Fixed.   Carbonic Acid.
  Air Inflammable.  See Hydrogen.
  Air Vitiated.  A name given by ancient chemists to
nitrogen.
  Air Vital.   One  of the names of oxygen. 
ALB
87
   Albumen.  Is an  animal substance in the state of a
solid ;  it is white, insipid, inodorous, heavier than water ;
it is decomposed by heat, giving off the sub-carbonate of
ammonia, &c.   It also presents other characters similar
to fibrine,  but dissolves better  in potash  and  soda.
When brought  in contact with water which  contains a
little of  the deutoxide of hydrogen, it does not give off
oxygen like fibrine.  (Thenard, vol. iv. p. 359.)  If dried,
it becomes hard, yellow, semi-transparent; but if brought
in contact with water, it again assumes  its usual  form.
Solid albumen is obtained by heating water in which the
white of eggs has been diluted, and washing the coagu-
lum.   The albumen  of the eggs does not in its nature
experience alteration  by spontaneous evaporation, and
can preserve itself indefinitely.  Liquid  albumen is co-
agulated  by heat and by alcohol; it forms with all strong
acids, especially the nitric, compounds which  are white,
acid, and little soluble.   Fhosphoriu and  acetic acids do
not, however, affect it; chlorine and iodine act upon it,
and also tannin.  Potash and soda prevent its being co-
agulated  by fire.  With  the  exception  of the  alkaline
salts, almost all the salts in solution are  decomposed  by
albumen, which  forms a combination with their oxides,
and a small quantity of their acids, unless we except the
hydro-chloric  or hydriodic acids;  for in  this case the
precipitate would  only  be albumen with  the  metallic
chloride or oxide.
   Albumen on account of its power of effecting decom-
position  is frequently used  in  cases of poisoning with
metallic  salts.   It must not, however,  be used in too
great quantities, as an excess would  redissolve a part of
the precipitate which  should be formed.  According to
MM.  Gay-Lussac and Thenard, albumen is composed of
52-883 of carbon, 23-872 of oxygen, 7-540 of hydrogen,
and 15-705 of nitrogen, also a small quantity of sulphur.
 Albumen united to water and some salts, constitutes the 
88
A  L C
 white of the egg ; it is also found in all parts of animals.
 particularly in the liquid parts.  Its uses are various, the
 most common is that of clarifying different liquids.
   Alcahest.   An Arabic word  to express a universal
 dissolvent,  which was pretended by Paracelsus and some
 other alchymists to have been discovered.
   Alcaligen.   One of the ancient names for nitrogen,
 this being supposed to enter into the  composition of all
 the alkalies.
   Alchemy.   {Alchemia.)   That branch of chemistry
 which relates to the changing metals into gold ;  forming
 a panacea or universal remedy ;  an alcahest or universal
 solvent, and many other absurdities.
   Alcoates.    By these we understand such  definite
 compounds  as are formed by the solution of certain bo-
 dies in alcohol; this has been proved of the chlorides of
 calcium, manganese, and zinc, and of the nitrates of lime
 and  magnesia.   All  these  bodies were found  by  Mr.
 Graham to unite with alcohol in definite proportions, and
 yield crystalline compounds which are deliquescent and
 soluble both in water and alcohol.  Alcoates are formed
 by dissolving the substances in pure alcohol by means of
 heat, when  on cooling, a group of crystals more or less
 irregular is  deposited.  The salt and  alcohol employed
 for this purpose should be  free  from  water, as a small
 quantity of water prevents crystallization.
   Alcohol.  {Alcool.)  A colourless  liquor, very vola-
 tile,  of a strong and agreeable odour, a burning taste,
 boiling  at  174°, and  congealing  at 90°.   Its  density
 when pure is,  according  to  M. Gay-Lussac, 0-7923 at
60°.   According to the same chemist,  the density of its
vapour is 1-613.   A high temperature completely decom-
poses it;  it is easily inflamed on the approach of a burn-
ing body or by an electric spark.   Phosphorus, sulphur,
and iodine are little soluble in alcohol.  The vapour of
sulphur forms with it  a  peculiar compound.   Chlorine 
ALE
89
 produces with  it an  oily substance, accompanied with
 muriatic and carbonic acids.   This oily matter seems to
 be a combination of chlorine and of  per-carburetted hy-
 drogen.   When equal parts of alcohol and distilled water
 are mixed, the liquids expand and there is an elevation
 of temperature.   Potash, soda, ammonia,  and the vege-
 table alkalies are soluble in alcohol.  If a small fragment
 of barytes  is  put into anhydrous alcohol,  it will not dis-
 solve, but  on account of the little  wcter it co .tains  will
 expand.   {Thenard's  Treatise  on  Chemistry, vol. iv. p.
 133.)
   The action of the acids upon alcohol produces pecu-
 liar substances.  (See Ether.)   Alcohol in general dis-
 solves all  deliquescent  bodies; it dissolves  the deuto-
 chloride of mercury, camphor, the essential oils, sugar,
 manna, and castor oil.  It dissolves  the animal oils  but
 in a slight degree.   Alcohol is in weight, composed of
 carbon  51-98,  oxygen 34-32, hydrogen   13-70,  or in
volume of 1 of  bi-carburetted hydrogen, and 1 of vapour
 of water.   Alcohol exists not ready  formed in nature, it
 is formed during the fermentation of sugared substances;
 and as it is  very volatile,  it is  obtained  by submitting
 these substances to distillation.  It usually contains water,
 which cannot be abstracted  but by  rectifying it with sub-
 stances which  have a strong  affinity for water, as the
 ehloride of calcium, and the acetate of potash.   In the
 arts the preparation of alcohol is carried on by means of
 an apparatus too complicated to be described  here.   Al-
 cohol is  employed  in pharmacy,  in the preparation of
 spirituous liquors, in the making of varnish, &c.; it is of
great use in pharmacy or the preparation of medicine.
  Alembic.  {Alambic.)  A chemical utensil  made of
 glass, metal, or earthen ware, and  adapted  to  receive
 volatile products from retorts.   It consists of a body, to
 which is fitted  a conical head, and out of  this head de-
 scends laterally, a beak to be inserted into   the receiver.
                         8* 
90
A  L K
This part of a chemical apparatus, used for distilling or
separating volatile products, by first raising them by heat,
and then condensing them into a liquid slate by cold, is
of extensive use in a variety of operations.
  Alkali Fixed Mineral.  Soda.   See Oxide of So-
dium.
  Alkali Fixed Vegetable.  See Oxideof Potassium.
  Alkalies.   Under the name  of alkalies is included a
certain number of metallic oxides, which possess peculiar
properties, or rather, which present the character of ox-
ides in a more marked degree than others.   They unite
more readily to acids than the other oxides, they redden
the curcuma paper,  and restore to the tincture of litmus
the blue tint which had been changed to red by the acids.
They are more or less sapid, sometimes even caustic.
Such are the oxides of potassium, sodium, calcium, stron'
tium, barium, &c.   (See  these oxides.)
  Alkalies  Vegetable.  These are  the  immediate
principles of vegetables,  remarkable in this, that it is al-
most  always to them, that vegetables owe  their active
properties, since they can combine with acids, and form
peculiar salts, which  often have more action upon the
animal economy than the bases themselves ;  they always
contain a certain quantity of nitrogen.  These bodies
possess many properties similar to the resins ;  like  them
they are insoluble, or little soluble in water, while on the
contrary they are soluble in alcohol, which circumstance
has led many chemists to suppose that they were only
a combination of ammonia with a modified resinous mat-
ter which some have named sub-resin.  As this hypothe-
sis is not sufficiently supported we shall continue  with
MM. Pelletier and Caventon, to  regard them as a sepa-
rate class in the immediate principles  of vegetables.
Carbon is the predominant element in their composition. 
ALL
91
  Alloy or Allay.*  A  great number of metals can
combine with other  metals, and the result of this com-
bination is called an  alloy.   Such combinations  are
termed amalgams when mercury enters into their compo-
sitions, binary alloys  when they result from the union of
two metals, ternary, quarternary, &c, when they are com-
posed of three or four metals.   The affinity of metals for
each  other being feeble, it follows  that alloys are made
in various  proportions,  and that these properties  differ
little from those of the metals which compose them.   In
natural alloys however, the proportions appear constant;
also in  some  of those  which are  artificial,  and which
may be made to crystallize.   They are generally more
brittle than the metals,  and sometimes a  brittle alloy is
obtained from two  ductile metals ;  the reverse of this is
not often.   Their density  is  sometimes greater, some-
times less,  than  the  mean  density  of the constituents;
their  fusibility is  often increased.  Alloys are usually
prepared by heating  together the metals of which they
are composed ; it is thus that lead is separated from cop-
per ; this  process is called eliquation ; if the metal is vo-
latile, it may be driven  off by a strong heat.   Platina is
obtained by  the latter  mode.   There are few natural
alloys which  do not contain either arsenic, lead,  or anti-
mony.  Among the  alloys employed in  the arts with
amalgams, are those  of  tin ; this is employed in the man-
ufacture of looking glasses.  For this purpose, is spread
out upon a flat table, a leaf of tin, which is then covered
with mercury; the glass  being applied,  the amalgam
remains upon its surface.
  An amalgam of silver is  formed of 1 of silver and 8 of
mercury.   It is obtained by heating to redness, 1 part of
small pieces of silver, and throwing them into a sufficient
quantity of mercury, (for  example  16 parts)  which has
* French term, Alttagts; 
02
ALU
 been previously heated ;  the amalgam should be shaken,
 then pressed in a chamois skin ; the mercury in excess
 passes out, and a soft amalgam is obtained ;  this is used
 for silvering. That of bismuth, formed of 1 of that metal,
 and 4 of mercury, is employed for silvering glass globes.
 Amalgam of gold is prepared like that of silver ;  it is used
 for gilding brass.  Among the binary alloys, is 1 of copper,
 with 9 of gold; this is used for  coin, vases  of  different
 kinds, and ornaments of gold. An alloy of 1 of copper, and
 9 of silver, is also employed in making coin and  other ar-
 ticles of silver.  That of  100 of copper, and  11  of tin, is
 used in making guns.  That  of 78 of copper and 22 of
 tin, is called brass; that  of 2 of copper, and about 1 of
 zinc, constitutes  yellow  copper, whose  uses  are well
 known.  That  of 1  of tin  and 2 of lead, is used under the
 name of plumber's solder.*  That  of 8 of tin  and 1 of
 iron, is employed  in tinning copper   An alloy of iron
 and  tin  constitutes what  is called  white  iron,  but the
 alloy takes  place only upon  the surface of the plates of
 iron.   An alloy of 20 of antimony, and 80 of lead, is used
 in the manufacture  of printing types.   Among the com-
 pound alloys, there are few which present any remarkable
 properties,  except that of 8  of bismuth, 5 of lead, und 3
 of tin ; this melts in boiling water—if a small quantity of
 mercury is  added, it becomes still more fusible ; it is often
 used for plugging the teeth.  A small  piece is introduced
 into the cavity of the tooth; this  is melted by applying to
 it a heated metal.   While in this soft heated state, it is
 pressed upon by the finger, covered  with a thimble of In-
dian rubber.  The different alloys are easily prepared ;
it is  only necessary to stir the mixture when it is fused^
that layers of different densities may not be formed.
  Aludels.  These are pots without bottoms, and which
may be so adjusted to each other as to form pipes.
' Webster says, equal parts of tin and lead. 
A  L U
93
   Alum.  Under this name is known a salt whose com-
 position  varies, but which has always for its base, the sul-
 phate of alumine, united to the sulphate of potash, or the
 sulphate of ammonia, and sometimes to both at the same
 time.  It is true that for the sulphate of alumine, might be
 substituted  sulphates, whose oxides like  the oxides of
 alumen,  should contain  3 atoms of oxygen for 1 of the
 metal, (such as the peroxide of iron, tritoxides of manga-
 nese and chrome,) but although the same laws of compo-
 sition would exist,  the compound could  not properly
 speaking be  called alum.  Alum is then a  double  or
 triple salt, without  colour, reddening the tincture of lit-
 mus, soluble in its own weight of boiling water, and in 15
 parts of  cold water.   If submitted to the action of fire, it
 melts in  its own water  of crystallization,  afterwards
swells, loses its water of crystallization, and forms a white
mass known by the name of calcined alum   Water has
little action upon it.  If  heated still more intensely, there
will remain only the alumine and the sulphate of potash,
 when the   alum is  not based upon ammonia.  Alum
 usually crystallizes in octohedrals, but when it contains a
 little excess of potash or alumine, it takes the cubic form.
 Heated with sugar or a vegetable substance containing an
 abundance of carbon, it forms a product called pyrophorus.
 (See this word.)  If into a solution of alum is introduced
 potash or soda until  the excess of the acid be saturated,
 the precipitate which is  formed is a double sub-sulphate.
  Alum based upon  potash  is formed of sulphate of alu-
mine 36-85, sulphate of potash 13-15, water 45-00.  That
based upon ammonia, is composed of sulphate of alumine
38-88, sulphate of ammonia 12-96, water 48-15.  Alum
is  employed in medicine, and often in  the  arts.  In
washing clothes it is  used for purifying the water ;  tallow-
 chandlers use it to give solidity to the tallow, &c.  Alum
 is not common in nature, but the elements of which it is
 imposed are often found.  It  is not  unusually  pre. 
9i                    A M B
 pared by a direct process.   When  it is already formed.
 as at Solfaterra, near Naples, it is sufficient to lixiviate
 the earths which contain it, and to crystallize the liquor.
 In the  neighbourhood  of  Vesuvius, it  is in the state
 of an  impure  sub-sulphate of potash  and  alumine;
 it is  roasted, exposed to the air, and alum is  then ob-
 tained from it, as in the process already described.  In
 France  almost  all the alum  is obtained from  natural
 mixtures, which form with argillite ;  these mixtures form
 extensive beds, in man)' departments, particularly in the
north.   It is  sufficient to expose these substances to the
 air, and to keep them  moist  during a certain time ;  the
 proto-sulphate of iron, and the  sulphate of alumine  are
soon formed;  these are lixiviated, evaporated, and  crys-
tals of the sulphate of  iron  are   formed; the  mother
waters are treated by the sulphate of potash and alum is
obtained : this is purified by a new crystallization.
   Alum  {Alum) Calcined.   Common alum which  has
been fused and deprived  of its water of crystallization.
   Alumine.   See Oxide of Aluminum.
   Aluminum.  This metal has never been procured in a
state of purity.  It appears to have been obtained only in
small quantities, alloyed with iron and steel, but it has never
been separated from them.   In combination with oxygen,
under  the form of alumine, it is  extensively diffused
through nature, though seldom pure.
   Amalgams.   These are combinations of mercury with
the metals.   See Alloys.
   Amberine.   A  brilliant brown  substance, insipid, al-
most inodorous,  fusible at 86°, volatilizes, and partly  de-
composes at  a temperature a little  above that of boiling
water. Nitric  acid transforms it into amberic {ambreique)
acid.   (See this word.)  Water does not dissolve it; this
is not the case with ether and alcohol, for it was obtained
by Pelletier and Caventon, by treating ambergris with the
last named liquid. 
•V M M
93
   Vmer.*   By this  name is  designated  a yellow sub-
stance which is obtained by treating muscular flesh with
nitric acid.
   Amidon.   See Starch.
   AMiDiNE.f   A peculiar substance, spontaneously pro.
duced from the  jelly of starch.   According to M.  de
Saussure, it is distinguished from inulin, in  being like
starch  coloured  blue  by  iodine,  little soluble  in cold
water, not forming jelly with boiling water, but a viscous
solution with potash ;  it differs from artificial gum, in not
being soluble in all proportions in cold water, in colouring
blue the aqueous solution of iodine, and in  forming with
water a solution which is congealed by the sub-acetate of
lead.
   Ammonia gaseous.  Ammoniacal gas is colourless, of
a very pungent odour ; its specific gravity, compared to
that of the air, is 0-5912.  It gives a deep green colour
to the tincture of violets, extinguishes combustion, and
liquefies when exposed to a low heat.   A small quantity
only is decomposed, when exposed to  an elevated tem-
perature ; but if at this temperature it is brought in con-
tact with metallic wire, particularly that of iron or cop-
per,  it is entirely decomposed, and changed into hydro-
gen and nitrogen.  As these metallic wires experience no
alteration, the effect of ammoniacal gas  has  been attri-
buted to the multiplying of the points of contact, increas-
ing of course the temperature, and thus  favouring the
decomposition of the gas.  The same phenomena may be
produced by substituting for  the  metallic  wires,  sand,
fragments of glass, porcelain, &c.   Oxygen with heat de-
composes the ammoniacal gas, forming a small proportion
of nitric acid.   Iodine readily  combines  with this gas ;
the result is a liquid iodide of ammonia.   Chlorine also
decomposes a portion of ammoniacal gas; the result is

          *  A term in the French language, signifying bitter.
          ' From Amidon, starch. 
96
A  M  M
  a hydro-chlorate of ammonia,  and nitrogen is set free
  Water dissolves near 780 times its  volume at the  ordi-
  nary temperature and pressure ; it is then known under
  the name of liquid ammonia.  Owing to this great affinity,
  a piece of ice introduced into a j ar of ammoniacal gas, soon
  becomes liquid.
    Ammonia LiauiD.  It  was formerly known under the
  name of volatile alkali, or spirit of hartshorn. It presents
  similar characters to the  gas ; if submitted to the tempe-
  rature of 212°, it gives off the greatest part or the whole
  of the gas which it contains.   It  precipitates yellowish
 green with the muriate of platina, does  not precipitate
 the nitrate of silver, forms in the solution of the sulphate
 of magnesia a white precipitate, which is an  ammoniaco-
 magnesian-sulphate,  and gives to the solution of the sul-
 phate of copper, when in excess, a beautiful blue colour.
 Ammonia dissolves zinc,  oxidating it, and  disengaging
 hydrogen, which proceeds from a small  quantity  of de-
 composed water.   It  dissolves  copper,  but  without any
 disengagement of gas ; the solution is colourless, but if
 exposed to the air, it absorbs oxygen, and takes a blue
 colour.  It also dissolves a number of oxides, particularly
 when they are hydrated ; these are the oxide  of silver,
 the deutoxide of arsenic, the deutoxides and the tritoxides
 of antimony,  the oxide  of cadmium, the protoxide of
 iron, the deutoxide of mercury, the protoxide of cobalt
 the protoxide  and deutoxide  of copper, the deutoxide
 of tin, the protoxide  of  nickel, the  deutoxides of gold
 and platina,  the oxides  of tellurium  and zinc.  These
 combinations  are  ammoniurets.   (See this word.)
   Ammonia possesses in a high degree the alkaline pro-
 perties of potash and soda, combining with all the acids,
and forming  salts which  may be decomposed by heat.
Ammonia is employed in medicine,  and in chemistry as
a re-agent.  In order  to obtain  it,  a mixture  of equal 
A  M  M
97
parts of muriate of ammonia and lime, moistened with a
small quantity of water is introduced into a retort, which is
fitted to several flasks of Woulfe's apparatus. The retort is
at first heated moderately ;  ammoniacal gas being disen-
gaged, it is washed in the water of the first flask, and is dis-
solved in the others which must be kept at a low tempera-
ture, that the water which they contain may be saturated.
The heating of the  tube which  connects the first two
flasks, owing to the disengaged vapour of water, indicates
that the operation is completed. It sometimes happens that
ammonia  contains pyro-empyreumatic oil, because that
the muriate of ammonia, being made from animal sub-
stances, often retains a small quantity of this oil.  Its ex-
istence in ammonia may be tested, by pouring into it sul-
phuric acid, which at first forms the sulphate of ammo-
nia, but which being in excess, chars the oil, and colours
the liquor.  Ammonia may be impure, from its retaining
a little muriatic acid.   This may easily be known, by sa-
turating the liquid with nitric acid, and then pouring into
it the nitrate of silver, which, in case of the presence of
muriatic  (hydro-chloric) acid, forms an insoluble  com-
pound with the chlorine of that substance.
   Ammonium.  A  name  proposed by Davy and adopted
by Berzelius, in order to designate the metal, supposed to
be the radical of ammonia, of which  metal  oxygen and
hydrogen  may be considered as the oxides.
   Ammoniurets.  {Ammoniures.)  These are combina-
tions of metallic oxides, and in  some cases  perhaps  of
metals, of ammonia.   Those combinations were noticed
under the  article liquid ammonia, but all  have not been
obtained  in  a  solid state, for if the liquid ammonia  in
which the metallic oxides are dissolved, is evaporated, the
oxides are precipitated in proportion as the ammonia is
disengaged  in the  form of gas.   The  ammoniurets  of
mercury,  antimony,  platina,  silver,  arsenic, and cop-
per, have  however been obtained.  Except flee last twor
                          9 
98
A  N A
they are detonating, and appear to resemble in their pro-
perties the cyanates, or fulminates, which have been re-
cently investigated by Gay-Lussac and Liebig ; their pre-
paration requires great precaution, and should be attempt-
ed only in small quantities.
  Analysis.  {Analyse.)   It is the art of decomposing
bodies in order to learn the nature and proportions of their
constituents.  In order to treat  this subject extensively,
it would be necessary to examine a great variety of che-
mical compounds, and to cite many examples. Not being
able to go into a  detail of particular cases we shall con-
fine ourselves to those which are common to all species
of analysis;  referring those who would wish fully to in-
vestigate the subject, to the fifth volume of the Treatise
on Chemistry, by M.  Thenard.   Believing that no one
has developed the  principles of this science more clearly
and  methodically than this celebrated chemist, we  shall
borrow from him the short exposition of analysis which
our limits will permit us to give.
  When a solid body is submitted to analysis it must first
be minutely subdivided.   This operation should be per-
formed in mortars of porphyry, or by means of a file oi
a hardness greater than that of the substance to be divided,
without which precaution  the file itself would be operated
upon ; where this  happens to be the case, it is necessary
to determine by a preliminary experiment, the quantity of
matter taken from the  instrument, and to  keep a memo-
randum of  it.   After having properly  divided the sub-
stance to  be  analyzed,  a certain  quantity should  be
weighed, (say 14 grains,) in doing this the most delicate
scales should be used.   The substance being weighed, it
should be brought in contact with the agents which are to
effect  its total or  partial  solution;  after which, different
r.e-agents should be poured into the solution, in order to
precipitate  successively, as much as possible, the sub-
stances existing in it.  It  is always necessary to pour in 
ANA
99
 an excess of the precipitant, except it would dissolve the
 sensible qualities of the precipitates.   For example, in
 order  to extract the deutoxide of copper from the solu-
 tion of the  deuto-sulphate of this metal, we add more of
 the  solution of potash than is  necessary to  saturate the
 acid;  if it  were not thus, a part of the acid  would be
■united  to the oxide, and then  the precipitate, instead of
 being  a pure oxide, would be a sub-sulphate, or a mixture
 of the oxide and  sub-sulphate.  The precipitate, what-
 ever it may be,  should be washed until all impurities are
 taken away.  The washing should be made by decanting,
 or by means of  a syphon, or small tube, and sometimes
 by filtration.  In all these cases it may be known that the
 precipitate is cleansed when the waters of the  washing
 no longer contain any foreign  matter.   For example, if
 sulphuric acid be poured  into a solution of the nitrate of
barytes in order to separate this base, it is necessary to
 wash the insoluble sulphate  which is  formed, but at the
 time when the waters  of  the washing will no longer be
 affected by the  nitrate of barytes.   In all  cases, the
 different waters  of the washing must be united as long as
 there remain in solution any traces of the matter subjected
 to analysis.    The precipitate  being  washed,  the  next
 step is to dry it,  first by placing it over an alcohol lamp ;
 then when it is  brought  to a state of powder,  if it can
 resist a high temperature, to  heat it to redness in a cruci-
 ble ; after which it should be  weighed.   If, however, a
 high temperature would cause  its decomposition, the pre-
 cipitate should be submitted to the temperature of boiling
 water,  and  shaken occasionally, or placed in a vacuum
 upon hot sand, by the side of a capsule containing frag-
 ments  of the chloride of calcium.    The operations in
 analysis vary in different  circumstances.
   1st.  Suppose  that the precipitate has been separated
 by decantation,  and that it can be heated to redness with-
 out decomposition : it should be put immediately into the 
100
ANA
crucible where the calcination is to be made.  This cruci-
ble should be of platina or silver, and weighed before and
after  calcination, the difference of the weight will give
the quantity of the  precipitate.  But if the precipitate
cannot support so high a temperature without  a change
of state, and if, of course, it must be dried by some of the
other means described, it may be more convenient to put
it into a small capsule of porcelain, which must be (as in
ease of the crucible) weighed before and after drying the
precipitate.
  2d. Suppose the precipitate has been collected from a
filter, if the  substance can support a  red  heat, and the
materials of the filter would have no effect upon it, the
whole should be put into a  crucible ;  the filter will  be
consumed, leaving the precipitate.    In case the precipi-
tate cannot resist the action of red heat it must be dried
upon  the  filter itself, which  is extended  upon folds of
paper; deducting  from  the  whole  weight that  of the
filter ; this is done by taking a filter of the same size, dry-
ing it well, and weighing it.
  3d. When the precipitate would support a red heat, but
would be  affected by the principles  of the  filter,  this
should be spread upon folds of  paper, and the precipi-
tate be carefully removed from it to  the under fold of the
paper, by a horn or ivory knife ; or  rather after having
folded the  filter upon itself, the water of the upper  fold
may be  absorbed by applying to it two folds of bibulous
paper, which should be pressed upon it lightly ;  by this
means the matter upon  the  upper  fold will adhere so
closely to the lower fold, that the former may be removed
without  any of the  matter  adhering.    Afterwards with
the lower fold the same process may be gone  through as
with the filter, that is, to fold it, &c, as above described,
and the  precipitate will soon  be obtained in  a detached
mass.   It  should then be calcined to a red heat; with 
ANT
101
 regard to what remains on the filter, the quantity may be
 known by the method above described.
   It often happens in the  course of analysis, that it i?
 necessary to evaporate  certain  solutions  to  dryness.
 While  there is much of the liquid,  the evaporation is
 made without any loss of the  substance analyzed ; but
 when it  begins to thicken,  there is some danger if the
 heat is very great, that itVnay be thrown out of the vessel
 and scattered about in various directions.   This accident
 may be prevented by stirring the substance with a spatula,
 and gradually diminishing the heat.
   If the body to be analyzed is a liquid instead of a solid,
 the  same  operations will  be necessary, except the  first,
 or process of pulverizing.   In the analysis of the gases,
 there are  some points of resemblance to  the methods
 above described ;  but  there are parts in this operation pe-
 euliar to itself.   As in this kind  of analysis, the weight
 of substances is estimated by their volume, their specific
 gravity being  known, it  is necessary to  observe  the
 pressure to which they are submitted,  their temperature.
 and  even  when they are in contact  with  water, their
 liygrometrical state.
   Antimony.*  A metal of a bluish white colour, shining.
 gradually tarnishing by exposure to the air, of a lamellar
 texture, brittle, giving off an odour on being rubbed ; its
 density is  6-702.   It  melts  below red heat; and when
 suffered to cool slowly, it  often presents upon its surface
 marks of crystallization, which  have been  compared to
 fern leaves, and which are the indications of a cleavage
parallel to the faces of a regular octodron, which is the
primitive form of this metal.  It is not volatile, and has
no action upon air and oxygen.   It scarcely oxidizes in
humid gases ;  but  at  a certain  temperature it absorbs

  » Supposed to be derived from anli, against, and  monakos, a monk. The
injudicious use of it by Basil Valentine having, as  is said, occasioned the
 I'-athof manv of the fraternity of the monks.
                          9* 
102
A  N  T
oxygen, and, eliminating caloric and light, passes to the
state  of a  deutoxide.   It  combines  with  phosphorus.
iodine,  sulphur,  selenium,  and  chlorine.  When pul-
verized antimony is thrown into a flask containing chlo-
rine, the combination gives rise  to a  disengagement of
caloric and light.  With other metals  antimony forms a
great number of alloys.   Sulphuric acid does not oxidize
it without the  aid of heat.   Concentrated  nitric acid
oxidizes without dissolving it, eliminating the deutoxide of
nitrogen, and forming the nitrate of ammonia ; the metal
then passes  to  the second  degree of oxidation.  When
the nitric acid is weak, it only transforms the metal into
the protoxide, and dissolves it. Muriatic  acid  also dis-
solves it.  The weight of its atom is 5-625.
  Antimony is found in nature, in the  state of an oxide.
a sulphuret, and  a hydrated  sulphuret.   It is extracted
from the sulphuret, which is very  abundant in France.
As  this sulphuret is sufficiently fusible, the ore  is heated
in a large crucible, with  an aperture at the bottom ; this
crucible rests upon another, which is to receive the sul-
phuret as  it melts.  Sometimes  the ore  is heated in a
reverberatory furnace with  the bottom inclined;  and as
the metallic  matter separates from its dross, it runs into a
vessel prepared for  its  reception.   In some  cases the
sulphuret is slowly roasted, the oxidated matter resulting
from  this  process being mixed with the nitrate and the
acid tartrate of potash,  and  heated in  a crucible; the
metallic antimony takes the lowest  place.  The uses of
this substance in the arts are not numerous; it is more
frequently employed for preparations in pharmacy.
  Antimoniates.  Antimonites.   Berzelius  has thus
named the deutoxide and tritoxide of antimony with sali-
fiable bases,  combinations which are not  soluble  excepi
their bases are so.  Gay-Lussac considers these com-
pounds as simple  mixtures of oxide ;  and he  supposes
that the combustion which  takes  place among many o; 
A  P P
103
them when they are exposed to a high temperature, is
owing to the commencement of a combination, and not
to a very intimate combination, as the Swedish chemist
imagines. Most of the acids decompose these substances:
those which are soluble, that is, those of potash, soda, and
ammonia, are obtained directly, and the others by double
decomposition.
   Antimony Crude.  {Antimoine Cru.)   The sulphuret
of antimony.
   Antimony Diaphoretic.  It is a compound  of the
peroxide of antimony and potash, which  is  obtained by
throwing into a crucible heated to redness, in small quan-
tities, 1 part of pulverized antimony and 2 parts of the
nitrate of potash ;  a white mass  is obtained, containing an
excess of alkali; this is pulverized, and usually diluted in
water, which dissolves the potash that is in excess, and
which always takes with it a certain quantity of the oxide
of antimony.   The residuum is the diaphoretic antimony,
washed.  The waters of the washing, treated  by nitric
acid, deposite the white oxide of antimony, which the
ancients called pearlated matter of Kerkringine. The pro-
duct, which is  obtained by placing  in a vessel of cast
iron a mixture of 3 parts of the  nitrate of potash and 1
part of the sulphuret of antimony, and heating  it with
charcoal, is called the Rotrou's melting. It is a mixture of
potash, of the  sulphate of potash, and the oxide of anti-
mony.  These different preparations are employed  in
medicine.
   Apparatus.  {Appareil.)  A name given in chemistry
to a series  of vessels adapted to any particular operation.
There is of course a great variety in the kinds of appa-
ratus used ; and in treating of the preparations of a com-
pound, we  usually describe  the apparatus which  is best
adapted  for the purpose.   We shall here  only remark
upon  Woulfe's apparatus.   It consists of a series of 2, 3.
 1. and 5 bottles, which  communicate with each other by 
104
A  R S
tubes, either with or without a bulb ; but in the latter case.
care must  be taken to place at one of the tubulures  of
each flask a strait  tube of safety, to prevent absorption.
These bottles are usually adapted to a retort or matrass.
From the last bottle  proceeds a bent tube, the end  of
which is placed under water.   These bottles always con-
tain a liquid, and through this the gas which is not dis-
solved in the first passes on to the second, and so on
through the whole.
  Arcanum Corallinum.   A  name given by the an-
cients to the deutoxide of mercury upon which alcohol
bad been burned.
  Arcanum Duplicatum.   One  of the ancient names
for the sulphate of potash.
  Arseniates.  When submitted to the action of fire,
all, except  those of potash  and soda, are  decomposed ;
if the metal which it contains has little affinity for oxygen.
the arseniate is changed into the deutoxide of arsenic and
a metal; if the  metal can  pass  to  a higher  degree of
oxidation, the same phenomena appear, but the deutoxide
of arsenic volatilizes; as an example of the first  case,
we may notice the arseniate of silver ; of the second case.
flie arseniate of the  protoxide of iron  is  an instance.
Most  simple  bodies can  decompose the arseniates at a
temperature which varies in each of them.  Water dis-
solves  the  arseniates of potash,  soda, and  ammonia.
Sulphuric acid decomposes them  at  a moderate tempe-
rature ; but  at a high degree of temperature, arsenic
acid  decomposes the sulphate.
  Various precipitates are formed with the arseniates :
  1st.  The solutions of arseniates precipitate the salts ol
cobalt  rose-coloured;  the precipitate  formed of arsenic
acid  and the oxide of cobalt,  dissolving in an excess of
acid, should not be made in  a very acid solution of cobalt.
  2d. The arseniates  in solution are not precipitated by
muriatic acid : while the compounds of the white oxide of 
A  R S
105
 ■irsenic  and  an alkali  are  precipitated  white  by  this
 acid.
   3d. The  nitrate  of silver  produces in the solutions
 of arseniates a brick-red precipitate, composed of oxide
 of silver and arsenic acid.
   4th. The  salts of copper  precipitate a bluish white
 from the arseniate of copper.
   5th. It  is  sufficient to leave  the arseniates, during
 twelve or fifteen hours, in contact with sulphuric acid and
 some drops of another acid, in order to decompose them,
 and  to precipitate a yellow sulphuret of  arsenic.  {M.
 Orfila.   TraiU de Chimie, t. 1 p. 553.)
   In the neutral arseniates, the quantity of the oxygen of
 the oxide is to the quantity of the oxygen of the acid as 1
 to 7-204.  There are also sub-arseniates and acid arse-
 niates.   These  salts being almost useless, we will only
describe  that of potash, with which all the others may be
prepared by  double  decomposition.
   Arseniate of Potash.  ( With excess of acid.)  This
 salt may be crystallized  in four-sided prisms; it is very
 soluble in water;  with a high heat, it  first  melts, then
 becomes a neutral arseniate.   This, and  also the arse-
 niate of soda and ammonia, may be prepared  by a direct
 process ;  but it is better to heat to redness, in a crucible,
 a mixture of equal parts of nitrate of potash and of the
deutoxide of arsenic.  What  remains in the crucible is
then dissolved in water, and the arseniate is obtained by
 evaporating the liquor.
   Arsenic.   (Supposed to be  derived  from an Arabic
term Arsanek, signifying strong and deadly  qualities.)
Under this name is known the metal arsenic, and white
 arsenic, or the deutoxide  of arsenic, which  on account
of its solubility, and its corrosive action upon the animal
 economy, is rightly  considered  as a most deadly poison.
 We shall here describe only arsenic, properly so called,
 referring for the  consideration of white arsenic,  to  the 
100
A  R  S
 article oxide of arsenic {deuto.)   Arsenic is a metal of a
 steel  gray colour, and a shining fracture ;  its texture is
 granular and scaly ;  its hardness is not very great, and il
 is very fragile.   Its specific gravity is 8-308.  If exposed
 to  the action of heat in close vessels,  it  sublimes and
 crystallizes in tetrahedrons.  If exposed to the air, par-
 ticularly to damp air, it soon loses its brilliancy, and is
 covered with a blackish substance, which appears to be
 the protoxide of this metal.
   If small quantities of arsenic are thrown upon burning
 coals, it immediately absorbs the  oxygen of the  atmos-
 phere, volatilizes in the form of white vapours, having a
 strong smell of garlic ; this is the deutoxide  of arsenic.
 It unites to hydrogen, sulphur, chlorine, iodine, and sele-
 nium, and also forms a great number of alloys, to which
 it communicates its fragility.   Nitric acid with heat oxi-
 dizes it, and can even cause it to pass into the state of an
 acid;  although  when pulverized  in  the metallic state,
 arsenic acts upon a solution of the sulphate of copper,
 and forms a certain  quantity of insoluble arsenite of cop-
 per.   Arsenic is frequently  found in nature in the state
 of an alloy, sometimes sulphuretted, oxidated, and even
 in the state of  an arseniate.   Powdered arsenic is em-
 ployed for destroying rats.*   Arsenic  is  obtained  by
 roasting the ores of cobalt, which often contain it in con-
 siderable quantities ;  as  it  is very volatile,  it vaporizes
 and condenses in  receivers prepared  for that purpose.
 The greater part passes over in the state of a  deutoxide.
 but a certain quantity in a metallic state is also obtained
 by  sublimation;  in  order  to obtain it very  pure,  the
 metal is collected and sublimed in a cast iron retort.
  Arsenic, White.   See Oxide of Arsenic  {Deuto.)
  Arsenites.  These are combinations of the arsenious
 acid, or the deutoxide  of arsenic  with salifiable  bases j
these compounds  strongly  resemble  arseniates;  thev.
              * Hence it? common name, rats' bane 
ASP
10?
however, may be distinguished by precipitating the solu-
tion of the sulphate of copper green, while the arseniates
precipitate it a bluish white.   The arseniates, if exposed
to the action of fire in  close vessels, decompose; the
'trsenious acid volatilizes, or rather one part decompos-
ing, yields oxygen to the other, which passes to the state
of arsenic acid, and one portion of metallic arsenic vola-
tilizes.  This last circumstance does not take place ex-
cept when the base has a strong affinity for arsenic acid.
All the arsenites, except those of potash and soda, are
insoluble in water ; all are decomposed by a great num-
ber of acids.   Those which are soluble are obtained b\
a direct process ;  those which are  insoluble are prepared
by double  decomposition.   In  the neutral  arsenites the
quantity of the oxygen of the  oxide is to the quantity of
the oxygen of the  acid as 2 to 3.  The arsenite of cop-
per is employed in the arts as a green colour, and known
under  the  name  of Scheele's  green.  It is obtained  by
decomposing the  sulphate of copper by the arseniate of
potash.
  Arseniuretted  Hydrogen.  A colourless fluid, pos-
sessing the odour of garlic ; highly destructive to animal
life.   It is best prepared by digesting an alloy of tin and
arsenic in muriatic acid.   This gas was discovered  bv
Scheele.
   Ashes.  {Cendres.)  The fixed residue of combusti-
ble substances, which remains  after  they have  been
burned.  In  chemistry it is commonly used to denote the
residue of vegetable combustion.
  Asparagin.   A  vegetable  substance, colourless, of u
nauseous taste, capable of crystallization in  rhomboidal
prisms.  Submitted to the action of fire, it swells and
gives a charcoal  which can  burn without any  residue.
It is  slightly  soluble in water.   This solution does not
affect vegetable colours ;  is not changed by the infusion
of nutjralls. bv the acetate of lead, the oxalate of ammo- 
108
A  T O
 nia, the  muriate of barytes, or  the  hydro-sulphuret of
 potash.  It is insoluble in alcohol.   Its discovery is due
 to Vauquelin  and Robiquet.  These chemists obtained
 it by heating the juice of asparagus in order to coagulate
 the albumen, filtering and evaporating it; and then leav-
 ing the liquor to stand for fifteen or twenty days, during
 which time it forms  rhomboidal, hard, and brittle  crys-
 tals, which are  the  asparagin ; also acicular crystals,
 which appear to be mannite; these should  be carefully
 separated  from the  first, which  should be crystallized
 anew.
   Asphaltum.   See Bitumen and Coal Mineral.
   Assay or Essay.  This  operation consists in  deter-
 mining the quantity  of valuable  or precious  metal con-
 tained in any mineral or metallic mixture, by analyzing
 a small  part thereof.  The practical difference between
 the analysis and the assay of  an ore consists in  this:
 the analysis,  if properly  made,  determines the  nature
 and quantities of all the parts of the compound ; whereas
 the object of the assay consists in ascertaining how much
 of the particular metal in question  may be contained in
 a certain determinate quantity of the material under ex-
 amination.  Thus, in the assay  of gold or  silver, the
 baser  metals  are considered as  of no  value or  conse-
 quence ; and the problem to be resolved is simply, how
 much of each is contained in the ingot or piece of metal
 intended to be assayed.
  Astringent Principle.  The effect called astringency,
 considered as distinguishable by the  taste, is incapable
 of being  defined ; we can only refer to substances which
 by their taste  exhibit the  astringent principle, as the
 husks of walnuts, green tea, and particularly nutgalls.
(See Tannin.)
  Atmosphere.  See Air Atmosplieric.
  Atom  and Atomistic Systems.  It is  supposed that
bodies  are formed  of infinitely  small  particles  called 
A  T O                    109
Htoms.   Now it is known that all chemical combinations
are submitted to general laws for the proportions of the
elements which  constitute them,  and that  every  com-
pound results from the juxtaposition of a certain number
of atoms.   It appears, according to Berzelius and Dalton,
to whom more particularly we are indebted for a know-
ledge of these laws, that one atom of an  element can
unite with 1, 2, 3, or a greater  number of atoms of an-
other element.  In the inorganic kingdom it has not yet
been discovered  that one atom of a body combines with
more than 6 atoms of another body.   These unions of
elementary atoms give rise to compound  binary atoms,
which by their combination produce still  more compli-
cated results, but which can always be traced to general
laws.  The quantity of water which the compounds often
contain, renders their laws of combination still more com-
plex.   Thus, 2 atoms of a body  may combine with  3
atoms of another, or 3 may combine with 4, but the com-
binations of these compound atoms also follow a general
law.  When  two binary oxygenated  compounds unite,
which  often  happens in  chemical operations and in na-
tural combinations, they unite  in such proportions, that
the quantity of the oxygen of the one is always a multi-
ple by 1,2, 3, and more, of the quantity of the oxygen oi
the other.  For example, in any substance  whatever the
quantity of the oxygen of the oxide is to the quantity of
the oxygen of tiie acid in the following proportions.
   In  the  combination of compound atoms,  ternary or
quaternary,  it is found  that the  oxygen of one of the
oxides is a multiple or sub-multiple by a whole number
of the oxygen of each of the other oxides ;  this  is ob-
served  in  many  minerals.  Berzelius  thinks that one
atom cannot  combine with more than twelve atoms, be-
cause  that a  sphere  cannot  be touched by more than
iwelve spheres of the same size ; but as has already been
remarked, there  are  few compounds  whose atoms are
                         10 
110                   A  1 O
united in this proportion.  In the carburet of iron, how-
ever,  this number is much exceeded, and organic com-
pounds exhibit many anomalies.
  Berzelius takes  for unity,  the weight of  an atom of
oxygen, which he called 100 ; he then subtracts the rela-
tive weight of the atoms of different bodies, and expresses
them  with reference  to this unity.  In sulphur, for ex-
ample, he found the weight of its  atom, in the following
manner :  " When a  sulphurretted metal oxidizes and
forms a neutral salt, the sulphur, in order to compose the
sulphite, requires  twice as much, and for the sulphate
three  times  as much  oxygen as the metal to form the
oxide.   If then the metal takes one atom,  the sulphur
takes 2 or 3 to form the sulphite or the sulphate, and if
the metal in the oxide took as many particles  of oxygen
as it before contained  particles of sulphur, sulphuric acid
would be composed of 1 atom of sulphur and 3 atoms of
oxygen.   This, with a very few exceptions, is  found to be
the degree of sulphuration which takes place, compared
with the degree of oxidation which a metal is most apt to
form, giving the  same relation between the weights of
the sulphur and oxygen as that which results from the
analysis of sulphuric acid, if we regard it as  composed
of 1  atom  of sulphur, and  3  atoms  of oxygen.  For
example ; 100 parts of silver  combine  with 7-3986 of
oxygen,  and with  14-9 parts of sulphur ; but if these
were so many atoms,  the weight of the atom of sulphur
would be to that of the atom of oxygen, as 100 to 201-16.
100 parts of lead take 7-725 of oxygen and give 146-44
of the sulphate of lead, or the oxygen,  of the acid is the
triple of that of the oxide of lead ; it follows that the
sulphuric acid which is formed, is composed of 23-175 of
oxygen and 15-54 of sulphur ;  but if these parts of oxy-
gen contain 3 atoms, and those of  sulphur contain but 1
atom  of sulphur, it follows,  that23^™ : 15-54 :: 100 :
201-65.  The particle of sulphur then weighs 201-65 ; 
A  T T
111
Sulphuric acid is formed of 1 atom of  sulphur  and 3
atoms of oxygen, and  sulphurous acid is formed of 1
atom of sulphur and 2 atoms of oxygen."—{Berzelius.)
  Dalton  takes for  unity in the weight  of atoms, the
weight of hydrogen, because this substance has the least
specific gravity of all others known, and of course com-
bines in the smallest proportions.   Berzelius and  others
prefer oxygen, as being the  substance most  common  in
combinations.  Berzelius states  its atom as weighing
100;  others (which  in fact amounts to the same) state it
as weighing 1.  It is very easy to ascertain the weight of
the atom of any substance  relatively to  either of these
numbers.   It  is only necessary to divide or multiply this
weight by 100.
  Atropine.   A  name given by Brandt to a peculiar
substance which  he extracted from  the   Atropa  bella-
dona, and to which he  attributes alkaline  properties.   It
is obtained by saturating  the  infusion of the  plant with
magnesia, and heating the precipitate with alcohol.  On
cooling, the atropine is deposited in the form of brilliant
needles, translucent, insoluble in cold water, a little solu-
ble in warm  water, and  scarcely soluble in ether.   It
forms with acids crystallizable salts.   When these solu-
tions are evaporated, they diffuse through the air vapours
which cause a dilatation of  the pupil of the eye.
  Attraction.   This is  the basis of all physical pheno-
mena ; or it  is that action  which bodies at a  distance
exert upon each other, according  to  laws derived from
their  size and distance, and the peculiar  nature of their
substances.   It is also  the basis of all chemical phenomena,
or the action by which bodies placed in contact, act upon
each other by affinity.  In the first instance,  this force
has received the name of planetary attraction;  it  is this
which retains the  heavenly bodies in their orbits,  which
by  a combination  of forces, prevents  their  irregular
movement, and which, in a word, maintains the harmony 
112
A  T T
of the universe.   In the second instance, attraction doc^
not act at a distance, but only at the point of contact, or
when the molecules (see this word) touch each other, and
it then receives the name of molecular attraction.
  Since the molecular attraction is all that can take place
in the bodies which cover the surface of the earth, since
it is this which occasions all chemical combinations, it will
be  this  kind only that we  shall here consider.  When
the molecular attraction takes place between particles of
the same  nature, it is called cohesion.  Thus the force
which prevents  the  molecules of sulphur or iron from
flying off from their state of union with the other mole-
cules, is  called  cohesion ; but that force which unites
iron to  sulphur, or which  retains the molecules of sul-
phur in connection with those of iron, is  affinity, or that
tendency by which the molecules  of one substance com-
bine with those of  another substance.   These two forces
cohesion and affinity are often opposed to each other ;
thus, when two bodies are solid, they can seldom be made
to combine chemically ; if one is liquid, the cohesion oi
the other may present an obstacle to their combination ;
but if both are liquid, they will unite unless their affinity be
very feeble.  When the affinity is feeble, the compound
which results partakes of the properties of the two sub-
stances from which it is formed ; but if the affinity is
very  strong, the  new  substance  possesses  properties
which are  very  different from those of the constituent
principles.  The combination is also promoted by the co-
hesion which is produced.  As for example, if into a solu-
tion of the nitrate of barytes,  should  be poured some
drops of sulphuric acid, immediately will be formed an
insoluble  and very dense compound,  which  probably
would not have been formed so readily if the density had
been less.
   Affinity may be modified by different causes ;  the most
powerful of all is the electrical states of  substances ; i' 
ATT                    113
has even been maintained, that affinity is only a  modifi-
cation of electricity, and wholly the result of the  electri-
cal states of different bodies.  It is supposed that a body
positively  electrified, combines with  a body  negatively
electrified ;  and that «n every binary compound, there
exists an electro-positive element, and an  electro-negative
dement; that the electro-negative substance can become
electro-positive in relation to another body, and so reci-
procally.   It follows from this  hypothesis, that two sub-
stances will combine much more strongly, when they are
both strongly electrified, the  one positively, and the other
negatively.
   Caloric  is  also one of the forces which  modify affi-
nity, as it can interpose between the molecules of  bodies,
and keep them at different distances ; a great number of
combinations  are effected by its assistance, which, with-
out it, would  be  vainly attempted.  But  if between the
molecules of a substance, caloric  is  interposed in  such
a quantity that the molecules of this substance are found
a certain distance from each  other,  (this distance is called
their sphere of attraction,) it follows, that these molecules
separate, and the attraction of affinity is destroyed ; this
is the case in distillation, the roasting of minerals, die.
This caloric favours the  combination of solid, but  not vo-
latile substances ; on the contrary, it  is unfavourable to
the combination of gaseous substances, whose molecules
are already comparatively distant.   Pressure  has an op-
posite effect to that of caloric, since  its  tendency is to
bring together the molecules of bodies; it is injurious to
the combination of solid bodies, and favourable to that of
gases :  this is demonstrated by experience.
   The  relative quantity of the bodies which  are to be
combined has much influence upon affinity.   As bodies
combine ordinarily with each other in the relation of 1
of the one body with 1,  2, 3, or more of the other, if to
a given weight of a body represented by 1, is presented
                          10* 
114                   A Z O
 the weight of another body represented by 1, the combi-
 nation will be more easily effected  than if to this bodv
 was presented the weight of another body represented
 by 2, 3, or a greater number ; and if we should attempt to
 decompose a compound of 1 of the  one body, and  3 of
 the other, it  would be  seen that  this compound would
 easily leave 1 part of the substance which contains 3:
 less easily 1 part from the substance which contains 2,
 and with  difficulty would leave the  last portion  of the
 body which  combined with  it; thus  the affinity of one
 body for another, is in an inverse proportion to the quan.
 tity of the other body.   The density  of bodies, as has
 been already observed in remarking upon cohesion, pre-
 sents an obstacle to their union ; but this may be modified
 by caloric and pressure.  There  are few substances in
 which the chemist has not been able to overcome the re-
 sistance of affinity; the means of doing this are various,
 ajid often very complicated ;  many forces may be made to
 act upon  a  substance  which seldom effectually resists
 when the decomposing forces are judiciously employed.
 All the processes which may be resorted to in the treatment
 of different substances can only be known by a  knowledge
 of the action which bodies exercise upon each other, of the
phenomena which accompany this action, and of the com-
pounds which result from it; it is this knowledge which con-
 stitutes Chemistry.
   Aerate.   A name proposed by  Pelletier, for the com-
 binations of auric acid with alkalies.
   Aurum Musivum.   The proto-muriate of tin.
   Azote.  From the Greek a without, and zoe life, signf
 fying to deprive of life.   See Nitrogen.
   Azote Carbonated.   See Cyanogen.
   Azote Oxymuriated.  See Chloride of Nitrogen.
   Azotures.  A name  given to combinations of azote
 (nitrogen) with different combustible  bodies ;  these are
 described under the articles, Ammonia,  Chlorine, Cyano. 
B A L
115
»<:n, and Iodide of Nitrogen.  Gay-Lussac and Thenard
in their brilliant experiments upon  metals, obtained am-
moniaral azotures of potassium and sodium ;  they per-
ceived that by fusing these two metals in ammoniacal gas,
an  action took place, giving rise  to a very fusible olive
green substance, formed of potassium, or sodium, of azote
and ammonia, and one volume of hydrogen, exactly equal
to that which gives with water the quantity of potassium
employed.   If this green substance is exposed  to heat, it
first melts,  then  decomposes, and is converted  into an
azoture of potassium or sodium.   It  absorbs moisture
from the air,  changing itself into ammoniacal gas  and
potash, or soda ; it decomposes water instantly, with a dis-
engagement of light.   The acids decompose it, forming a
base of ammonia and potash or soda.   It decomposes in
alcohol, and may be preserved in the oil of naphtha. {Re-
cherches physico-chimiques de MM.  Gay-Lussac et The-
nard. )
  Azoture of Carron.  See  Cyanogen.
  Azoture of Chlorine.   See Chloride of Nitrogen.
  Azure.   A name given to glass,  coloured blue  by the
oxide of cobalt.   This glass in a melted state is  poured
into water,  and  afterwards pounded;  the powder is
mixed with water, and after a short time decanted.  The
iizure, which is last deposited, is the most brilliant.


                        B.

  Halance.   The beginning  and  end of every exact
chemical process consists in weighing.   With  imperfect
instruments this operation will be tedious and inaccurate ;
but with a good balance  the results will be satisfactory ;
and much time, which is so precious in experimental re-
searches, will  be saved. 
116
B  A L
   The balance is a lever, the axis of motion of which, is
 formed  with an edge, like that of a knife, and the two
 dishes at its extremities are hung upon edges of the same
 kind. These edges are first made sharp, and then rounded
 with a fine hone, or piece of buff leather.  The excel-
 lence of the instrument depends, in a great measure, on
 the regular form of this rounded part.   When the lever
 is  considered as a mere line, the two  outer  edges are
 called points of suspension,  and the inner the  fulcrum.
The points of suspension are supposed to be at equal dis-
tances  from the fulcrum, and  to be  pressed  with equal
 weights when loaded.
   Balloon.   {Ballon, or baton.)  A large glass receiver
 in the form of a hollow globe.  For  certain chemical
operations balloons are made with two necks, placed op-
posite to each other ; one to receive the neck of the re-
tort, and the other  to enter the neck of  a second balloon :
this apparatus is called enfiladed balloons.   Their use is
to increase the whole space of the  receiver, because any
 number of these may be adjusted to each other.    The
 only one of these  vessels  which is generally used, is a
 small oblong balloon with two necks, which is to be luted
to the retort,  and  to the receiver, or great balloon; it
 serves to remove this receiver from the body of the fur-
nace, and to hinder it from being too much heated.   The
term balloon is also applied to a spherical bag filled with
a gas of small specific gravity, by the buoyancy of which
it is raised into the  atmosphere.
   Balsam.  {Bourne.)  The term  balsam was anciently
 applied to any strong scented natural vegetable resin, in-
flammable, not miscible with water, and supposed to be
possessed of many medical virtues.  All the turpentines,
the Peruvian and copaiva balsam, &c, are examples  of
natural balsams.   Besides, many medicines compounded
of various  resins, or oils, obtained the name of balsam.
Chemists now restrict this term to vegetable juices, con- 
b  i; L
in
si.sting of a  substance of a resinous nature, capable of
affording benzoic acid.   They are insoluble in water, but
readily disssolve in alcohol and ether. The liquid balsams
are Copaiva, Opo-balsam, Peru, Styrax, Tolu ; the con-
crete are Benzoin, Dragon's blood, and Storax.
  Barhm.   This metal is hardly known.  In nature its
oxide is found  combined with sulphuric and carbonic
acids.  This is heavier than water, of a dark gray colour :
it readily attracts oxygen from the atmosphere, and passes
to the state of an oxide.   (See Calcium.)
  Barytes.   See oxide  of Barium.
  Bases Salifiable.  All such substances as uniting to
acids form salts :  as  ammonia, and the different metallic
oxides.
  Bases.   Vegetable Salifiable.   See Vegetable AJ
ladies.
  Bassorine.  This substance was first extracted from
the gum of Bassora.  Pelletier has since discovered it in
the assafcetida, and Braconnot in St. Ignatius' bean, and
some other substances.   It has some resemblance  in its
properties to gum  adraganth, particularly in  swelling in
either cold or boiling water.   It easily dissolves in water
containing a little nitric acid.   Treated with potash it
disengages ammonia. It is very easily obtained by treat-
ing gum Bassora with water, alcohol, and  ether.   As it
does not dissolve in any of these liquids the residue con-
tains  only some vegetable  remains, which  are  easily
separated by continued washings.  {Vauquelin.)
  Bell-Glass.   {Cloche.)   A hollow, cylindrical article
of glass or crystal, open  at its base, round and closed at
the top, which is terminated  by a stopper.   Some bell-
glasses, instead of the glass stopper, have a stop cock of
copper ; others,  one graduated into  a certain number of
equal degrees.  Bell-glasses  are  of great use in chemis.
iw, eith'M- to  collect  gas, to transfer, or to measure it. 
118
B  I  L
  Benzoates.   Combinations of benzoic acid with salifi-
able bases.   These salts are all  easily decomposable by
calorie ;  those of the metals of the first two sections* arc
soluble and crystallizable, those of zinc and iron the most
so.   The others are insoluble.  In  the  benzoates,  ac-
cording to Berzelius, the oxygen of  the  base is to the
acid as 1 to 15-098.  All these salts are without use, and
very little studied.
  Bezoard  Mineral.  It was  by this name that the
oxide of antimony was  formerly known, when  precipi-
tated from its solutions.
  Bi (From bis, twice.)  In composition it signifies twice
or double.
  Bi-Arseniates.  See  Arseniates.
  Bi-Phosphates.  See  Phosphates.
  Bi-Seleniates.  See Seleniates.
  Bi-Sulphatks.   Sec Acid Sulphates.
  Bile.   A bitter liquid,  more or less viscous, of a green-
ish yellow, heavier than  water, found in most animals.
Bile submitted  to distillation, gives a  volatile colourless
product, of a nauseous smell, precipitating by  the acetate
of lead.   The  dried residue forms nearly one eighth of
the bile which was employed :  it is slightly deliquescent,
and almost entirely soluble in water and alcohol, decom-
poses at a  high heat, gives the  same products as  all
animal substances; these  contain many salts, particu-
larly soda.  Eight hundred parts of the bile of the  ox.
according to Thenard, consists of water,       700
      Resinous matter,.......15
      Pioromel,.........69
      Of a yellow matter,......4
      Soda,     ..........4
      Phosphate of soda,......2
      Chlorides of sodium,and of potassium,     3-5
      Sulphate  of soda,.......0-8
      Phosphate of lime,......1-2
               * See Metals, Thenard's sections. 
B  I T
119
and  some  marks  of oxide  of  iron.  The  bile of man
differs little from  these  proportions,  but contains more
pioromel.
  Bismuth.   A metal of a yellowish white colour, very
brittle, of a lamellar structure, crystallizes in cubes ; its
specific gravity is  9-822, it fuses at 256°; it tarnishes in
damp air ; burns at  a very  high temperature, with a dis-
engagement of light.  It unites with most of the metals.
as phosphorus, sulphur,  selenium, chlorine, and iodine.
This metal seems not to have been known very anciently,
though Agricola, in  1520, pointed out the means of ob-
taining it;  it was  formerly  called glazed tin.   In nature
it is  found in the  state of an oxide, and combined with
sulphur and various  metals.   It is not common, is easily
extracted by introducing  the  mineral containing it  into
iron cylinders placed across a furnace ; one of the ex-
tremities is entirely closed; the other, through which  the
metal flows, is partly closed by  a luting of clay.  When
heated, the bismuth melts and flows into iron crucibles ; it
must then be submitted to a high heat, in order to exclude
the  arsenic.  Its  purity is ascertained by  treating it
with nitric acid ; it will dissolve entirely if pure, otherwise
the arseniate of bismuth is deposited.
  A preparation of bismuth  known by the name of pearl
powder,  or  pearl  white, is sometimes used as a cosmetic,
though its effect upon the skin is injurious ; it is liable to
be turned black  by sulphuretted hydrogen gas.
  Bitumen.  The bitumens are substances either solid
or liquid, emitting an odour more or less strong.   Thev
burn,  leaving a  residue,  which  is  easily incinerated.
Liquid bitumen, or naphtha,  is transparent, of a yellowish
white colour, almost without taste ; it burns like essences
upon the approach of an  ignited substance, with a bright
but sooty flame.   There are many varieties, which differ
both in their consistence and their  colour as more or less
deep.   Naphtha is  found on the borders of the Caspian 
120
B  L O
 sea, in Calabria, in Sicily, and various other parts of the
 world, and  is procured  by distillation from petroleum.
 It is sometimes used instead of candles.
   Bitumen Solid, or Asphaltum. It is black, shining,
 friable, insoluble in alcohol, acquires an odour by rubbing,
 and burns with facility.  It is usually found on the surface
 of lake  Asphaltites; this  has  given  rise to its name.
 According to historians,  it  was this bitumen, which was
 used as a cement for the  walls of Babylon.  Naphtha, or
 liquid bitumen,  is,  according  to  the experiments  of
 Saussure,  composed of hydrogen, 87-60, and carbon,
 12-78.   It is employed  to preserve  potassium, sodium.
 barium,  &c.
   Black Lead.  See Plumbago.
   Blanc De Baleine.   See Spermaceti.
   Bleu  D'Outre Mer.   See Ultramarine.
   Blood.   This liquid is very abundant in most animals.
 Its colour in the  arteries is a lively red, and a deep purple
 in the veins of  animals containing red  blood.   Its taste
 is slightly salt, its specific gravity as found in  man,  is
 10-527 at the temperature of 60°.  Blood on standing
 for a short  time separates into  two  portions;  the one
 solid, called crassamentum  and the other liquid, which is
 called serum.  If exposed to a temperature  of 100°, it
 coagulates on account of the  albumen which  enters into
 its composition ;  alcohol also coagulates it; the different
 salts form with  it a precipitate  which results  from the
 union of albumen with the oxide of the metal; the pre-
 cipitate does not of course take place, when the oxide
 can form with the albumen a soluble combination.  This
is  the case with the  salts of potash,  soda, and some
others.   Blood is also coagulated by chlorine,  by sulphu-
rous and muriatic acid gases.  Venous blood in contact
with oxygen, becomes red,  as when it meets with air in
the lungs.  Potash and soda can also form soluble com-
pounds with fibrine ; they prevent blood from coagulating. 
B  L D
121
 According to Berzelius, blood  is composed of a great
quantity of water, of albumen, fibrine, a coloured  ani-
mal substance, a little oily matter, chloride of potassium
and sodium, the sulphate of lime, sub-carbonates of lime,
soda, and magnesia, of oxide of iron,  and acetate of soda.
This last substance has not been found by other chemists
in the  analysis  of  blood.  The  solid matter which  is
formed from blood, or the crassamentum, is composed of
fibrine, colouring matter, an oily substance, and a certain
quantity of water.   The serum  contains  the rest of the
water, with most of the salts and the  albumen.
   Blow Pipe.  {Chalumeau.)   A simple instrument, in-
vented for the purpose of directing the flame of a lamp
lor the analysis of minerals  and for  other chemical  pur-
poses.  It consists  of a tube of silver, copper, or glass,
about one eighth of an inch in diameter at one end,  and
the other  tapering to a much less size, with a very small
perforation.   A blow pipe has been  constructed by  Pro-
fessor Hare  of  Philadelphia, by which a stream of  oxy-
gen and hydrogen gas is conducted upon the ignited  sub
 stance ; this is called the oxy-hydrogen blow pipe.
   Blue of Cobalt, or Thenard's Blue. {Bleu de The.
nard, ou de Cobalt.)  A substance of a beautiful blue, which
 is substituted for ultramarine  in  oil  painting.  This co-
lour  is prepared as  follows: The  ore  of Swedish co-
bait  is  first  roasted in order to drive  off the arsenic  as
 much as  possible ;  it is dissolved in diluted nitric acid ;
the solution is then evaporated almost to dryness, the re-
sidue heated with distilled water, and the liquor filtered
in order to separate the arseniate of iron which is depo-
sited ; into the liquor is poured a solution of the sub-phos-
phate of soda, which forms a violet precipitate of the  sub.
phosphate of cobalt; this precipitate being washed,  one
part of it,  in  the form of a jelly,  is mixed  with 8 parts of
alumine,  also in a jelly.  This mixture is  dried upon
plates by  a stove ; when brittle, it is gradually heated to
                          11 
122
B  L 0
redness in a crucible ; this temperature is  continued lor
half an hour ;  it is then left to cool.   A result analogous
to this is obtained by employing one half part of arseniate
of cobalt,  and  8 of alumine, or the same  quantity of the
nitrate of cobalt with alumine, or alum based upon am-
monia.  The arts are indebted for the discovery of this
brilliant colour, to the learned Professor Thenard ; he
considers  it as composed of the sub-phosphate of cobalt
mixed with alumine.
  Blue Prussian.   A substance of a deep blue,  much
heavier than water, retaining it with tenacity.   It expe-
riences no alteration  at a temperature of 135°.   If sub-
mitted to  distillation  in a retort,  at a very high heat, it
gives off the hydro-cyanate of ammonia and the carbo-
nate of the same base.   Prussian  blue burns easily, leav-
ing a considerable residue of the oxide of iron.   Chlorine
changes it to green, but deoxygenating substances restore
to it its primitive  colour.  Water and alcohol  have no
action upon it.  Potash, soda, ammonia, barytes, strontian,
chlorine, and magnesia, decompose it, forming a cyanite
and a precipitate.  The peroxide of iron and the deutox-
ide  of mercury have the same effect.  Weaker  acids
affect it but little.  Many concentrated acids act upon it.
According to  M.  Robiquet,  sulphuric acid changes  it
white, without disengaging  any gas, or becoming charged
with any of its principles ;  if the acid is diluted with wa-
ter, the colour re-appears.
  The discovery of prussian blue  is due to a colour-ma-
ker, named Diesbach,  who prepared lake  from cochi-
neal, by mixing the decoction of this substance with alum
and a little of the sulphate of iron, and then precipitating
it by  an alkali.  Being at  a  certain time in want of pot.
ash, he borrowed  from Dippel, in whose laboratory  he
was at work,  some of the salts of tartar which had been
used  by that  chemist  in the distillation of animal oil.
The lake  precipitated by this alkali, instead of being red. 
B  L U
123
was of most beautiful blue.  Dippel, to whom the pheno-
menon was made known, perceived that it was the  effect
of the salt of tartar, and endeavoured to produce the same
effect  by the  agency of other alkalies,  and the  know-
ledge of the existence of prussian blue was thus com-
pletely established.  The manner of preparing it was for
a long time  kept secret.  In  1724,  Woodward,  in his
" Transactions Philosophiques," described it.   Many che-
mists,  particularly Macquer,  attempted to ascertain  the
nature of the substance ;  but it was reserved  for Scheele
to discover the  acid which  Bergman and Guyton  had
suspected.   It was  afterwards  studied by Proust, Ber-
thollet, Vauquelin, Robiquet, and Berzelius.
  The following is the process  made use of in the  arts
for obtaining Prussian blue :  A mixture of  equal parts
of dried  blood or horns, and  the potash of commerce, is
heated in a large ircn crucible, until it becomes clammy ;
when cold, it  is  thrown  into  fifteen  times its weight of
water, u.ud  uccasiuimlly stirred; at  tlie end  of" an hour,
the liquor which contains the hydro-carbonate of potash,
sub-carbonate of potash, and some other salts, is filtered.
To this liquor is added 4 parts of alum, and 1 part of the
sulpha1 e  of  iron ; this forms a very abundant precipitate,
composed of  alumine, the  hydro-ferro-cyanite of iron,
and a small quantity of the sulphate of iron.   When the
liquor  ceases to be coloured by adding these  salts, the
operation is completed.  The precipitate is washed with
many waters, which are renewed once in 12 hours.  It
is at first brown, then greenish brown, next bluish brown,
and from this shade  it  passes, by contact with the air, to
a deeper hue.  It  is left to drain, and  dried upon  the
strainers.  The  rationale of the phenomena presented
by this operation, is thus given by M. Thenard:  The
animal matter is decomposed by calcination, disengaging
water, carbonic acid, ammonia, oxide  of carbon, oil, car-
buretted  hydrogen  gas ;  in  a word, all the  products of 
124
BON
animal  matter.   The  residue is composed  of carbon.
potash  more or  less  carbonated,  cyanide {cyanure)  of"
potassium, sulphuret and chloride of potassium.   When
the residue is  thrown into water, the carbonated  potash,
the cyanide, sulphuret, and the chloride  of potassium,
dissolve;  the first remains inactive, and the three others
decompose the water;  from thence is formed the hydro-
cyanate, instead of the cyanide, the hydro-sulphate, &c.
Potash decomposes alum, uniting with its acid, and preci-
pitating its base; it is the same  with the sub-carbonate,
and the sulphate of  potash; the last two disengage car-
bonic acid, and sulphuretted hydrogen; the hydro-cya-
nate of potash forms with the proto-sulphate of iron, a
white insoluble precipitate of hydro-ferro-cyanate of the
protoxide of iron ; this also contains the hydro-ferro-cya-
nate of potash.  With the same sulphate of iron, the
hydro-sulphate of potash forms a black precipitate of sul-
phuretted  hydrogen, and protoxide  of iron.   The wash-
ings serve to dissolve tne soiuoie salts wnich arc foreign-
to the prussian blue, such as the sulphate of potash, &c.
and particularly to bring  the  oxide of  iron to the maxi-
mum  {the highest degree)  of oxidation,  by  means  of the
air contained in the water.   Prussian blue is then a hy-
dro-ferro-cyanate  of potash and of iron, mixed  with
alumine ;  or, as may be expressed, a mixture of the cya-
nide of potash and iron with water  and  alumine.
   Bone.  {Os.) Bones are solid, tasteless,  without odour,
 white, very hard and brittle in old  people, more  flexible
in children.   When submitted to distillation, they  give
all the products of animal matter :  heated in the air they
form  bone black ;  if burned  they  become  black ;  if
the heat is continued they become white, light, and fria-
ble ; if left to  themselves they  exfoliate, and in a few
days fall to powder.   If boiled, all the gelatine dissolves.
and nothing but the earthy part remains.   When bones
are digested  in weak  chloric acid all the  salts dissolve. 
BON
125
they are then flexible, elastic,  and are composed wholly
of animal matter.   This substance washed in  boiling
water may be considered as pure gelatine.  Bones vary
greatly  in their composition according to the age of the
individuals,  and the species of animals.  Fourcroy and
Vrauquelin who analyzed human bones, found them com-
posed of a large  quantity of the phosphate of lime, a
little of the phosphate of magnesia, phosphate of ammo-
nia, oxides of iron and manganese, some  traces of alu-
mine  and silex, gelatine, and  water.   MM. Proust and
Hatchett have also ascertained  the presence of the car-
bonate  of lime.   Berzelius thought he discovered fluoric
acid, but this has been confirmed by no other chemist.
  The following are the proportions of bone as given by
Berzelius : gelatine 32-17, blood vessels  1-13, fluate of
lime 2-00, phosphate of lime 11-30, phosphate of magnesia
1-10, water 1-20.  Vogel, who analyzed  the bones of a
cemetery which had been closed for  nearly 1100 years,
found that they contained no more gelatine, but a much
greater   proportion of  carbonate  of  lime than  fresh
bones.   The bones .of herbivorous animals, according
to Fourcroy and Vauquelin, contain the same principles
as human bones.  Berzelius found  the  fluate of  lime,
and Mr. John the  sulphate of lime in  those of the ox.
M.  Chevreul who  analyzed the bones of fossil marine
animals, found in them the sulphate of lime united to a
little animal matter 1|, water 10i,  phosphate of lime
iron and  manganese  6-7, albumen  1,  carbonate  of
lime 4, and some traces of the fluate of lime.  M. Bouil-
lon Lagrange found in analyzing the turquoise that it was
composed of phosphate of lime 80, carbonate of lime 8, phos-
phate of iron 2, phosphate of magnesia 2,  albumen 1l,
water and clay 6i.  The bones of fishes appear to be
formed  of a mucus similar to that  of the  nails and hair.
Thenard has made a  series of interesting  experiments
upon different parts susceptible of ossification (changing
                         11* 
126
BOK
to bone).  Teeth, in their composition, differ very httk
from bones.  Berzelius and Morrichini assert that they
contain some fluate of lime, but Fourcroy and Vauquelin.
and several other chemists, assert that they have  not
been able to discover in teeth any traces of it.  M. Las-
saigne has made the following analyses of human teeth :
		animal	phosphate	carbonati
		matter.	oflime.	oflime.
	["Teeth of a man aged 81	33	66	1
■n	" middle aged person -	29	61	10
	" '' child of 6 years	28-5	GO	11-5
a.'	" child aged 2 years	17-5	65	17-5
o	' infant aged 1 day	35	51	14
'-,	'• mummy of Egypt	29	55	15-5
	. * Enamel of human teeth	20	7-2	8
   Fourcroy and Vauquelin consider ivory  as formed of
the same principles  as bones.  Gay-Lussac and Mor-
richini  have discovered in it some fluate of lime.  It is
with ivory calcined to a certain degree, thus the beauti
ful velvet-like colour called ivory black is prepared.
   Borates Neutral.  {Borates Neutres. Combinations
of boracic acid with bases in which the salts are neither
acid nor much alkaline.  These salts are  little known  ;
Berzelius, however, has given the proportions of borate
of barytes ; according to him it  is formed of twice as
much acid as the sub-borate of the same base.
   Borates Sub.   {Borates Sous.)  Combinations of bo-
racic acid with an excess of the base ; these salts are
mostly  insoluble,  but those  of ammonia, potash, and
soda are soluble and crystallizable;  all the sub-borates
of the first four sections are undecomposable by fire,  on
account of the permanence of their acid ; but where'the
metals have not  a strong affinity for oxygen, they may
be decomposed;  the boracic acid being set free, the
metal is reduced  and oxygen disengaged.  The sub-bo-

0f*theUsrurhLan<1,VaUtlUeli'1 haVe f°Und in ,he e"aniel 0f human ,e«U " Uttlc 
BOB
12'
rate of ammonia whose base is volatile is easily decom-
posed, the ammonia set free, and the  acid remains insu-
lated.   The sub-borates are decomposed by all soluble
salts, which can  form with boracic acid, insoluble salts,
such as the chlorate of lime, the nitrates of  strontian, of
barytes, &c.  Nature presents us the sub-borate of soda
(borax) and the  sub-borate of magnesia ; the others are
the products of  art.  In the sub-borates the quantity ot
the oxygen and of the  oxide, is  to  the quantity of the
acid, as 1 to 2-696.
  Borate (Sub) of Ammonia.   {Borate sous  d'Ammo-
niaque.)  This salt is the  product of art;  it is obtained
by dissolving boracic  acid in an excess of ammonia; the
salt crystallizes  on cooling.   It greens the infusion of
violets, and  is decomposed by a red heat, giving off all
its ammonia.
  Borate  (Sub) of  Potash.   {Borate sous de Potasse.)
This  salt is  prepared  directly by combining potash and
boracic acid ;  it is little known.
  Borate  (Sub) of  Soda, or Borax.  {Borate sous dc
Sonde.)  This salt deeply greens the infusion of violets ;
it has an alkaline taste, dissolves in  twice its weight of
boiling water ; but much more cold water is necessary to
effect its solution.  It crystallizes in hexahedral prisms
with compressed summits ; it has an opaline colour and a
glassy fracture :  exposed  to fire,  it  loses its water ot
crystallization and is  transformed into  a substance called
glass of borax, which  soon tarnishes by attracting humi-
dity from the atmosphere.   M.  Dobereiner {"Annates dt
 Chimie  et Physique") thinks that it is decomposed  by
charcoal at a high temperature.  This salt is  known in
commerce by the name of borax, is found abundantly in
 nature, particularly in Tartary and China,  Ceylon, and
other places of  Asia  ; and also exists in Peru, where  it
 is found at the bottom of salt lakes.   Much of the borax
 of commerce  needs to be divested of an oily matter which 
128
B  O K
 <eems to be united to the excess of the soda; this is called
 tinckal, or impure borax ; that which comes from China is
 much more pure and easy to be refined.  Robiquet  and
 Marchand have published the process which they use in
 purifying it.  They first put the impure borax into a  tub.
 with water sufficient  to cover it; after letting it stand
 half a day, they add one  part of slaked  lime to 400 of
 borax ;  the liquor remaining until the next day, a sort of
 calcareous soap  is formed with the  oily matter which is
 deposited.  The  salt is afterwards separated  by means
 of sieves with large meshes ; it is redissolved by heat, in
 twice and a half its  weight of water ; 1 part of the hydro-
 chlorate {oxymuriate) of lime is then added for 50 of the
 borax.  The  liquor, filtered  and  concentrated to 20° of
 the aerometer, is turned into leaden cones, because  this
 form is favourable to crystallization ;  it should cool slowly
 to obtain such crystals as are valuable in commerce.
   This substance is also  extensively manufactured by
 combining directly boracic acid from  the  lakes of Italy
 with the sub-carbonate of soda.  It  is sufficient to heal
 the acid with the soda, and concentrate the solution as
 above described.   The  borax  thus obtained, though
 whiter than the  other, is less valued.   Borax is  often
 used in the arts.   It facilitates  the vitrification of many
 oxides, and forms with them glass differently coloured.
   Borax.   See Borate {sub) of Soda.
   Boron.   {Bore.)   A combustible substance, not me-
 tallic, pulverulent, of a greenish colour, insipid, inodorous.
 insoluble, infusible, without  action upon oxygen at  the
 ordinary temperature, absorbing it at an elevated tempe-
 rature with an elimination of light;  decomposing nitric
 acid,  and passing to the state of boracic acid.   This
 new substance is  found in nature but in a state of combi-
nation with  oxygen.   Gay-Lussac and Thenard disco-
vered  it by treating  boracic  acid with potassium and
sodium.  In order to obtain it, equal parts of the acid and 
B  R E
129
metal  are  introduced into a porcelain  or copper tube
hermetically sealed at one of the extremities.  It is then
heated  to redness ; one part of the acid is decomposed,
giving off its  oxygen to  the potassium  or sodium; the
other part of the oxygen not decomposed combines with
the oxide, and the  result of the operation is the sub-borate
of soda or potash,  and boron.   This salt is then dissolved
in water, and the boron precipitated.  This- substance has
been little studied.
   Borides or Borurets.   {Borures.) Combinations of
boron with  combustible bodies; but  little is known of
these compounds except that they  are brilliant and inso-
luble.   They  are  made  by  applying a  high heat to a
mixture of  boracic acid,  charcoal, oil, and iron  filings.
or a mixture of the acid and plaiina.   The masses which
result from  these  combinations have a  metalloidal ap-
pearance, and are  very fragile.
   Br ask.   {Brasque.)  Dust of pounded charcoal, with
which crucibles are  lined when  treating bodies which
have a strong  affinity for oxygen.
   Brandy.   See Alcohol.
   Brass.   See Alloys.
   Bread.   {Panis.)  Farinaceous vegetables  are con-
verted into meal by trituration, or grinding in a mill; and
when the husk or bran has been separated by sifting or
bolting, the  powder is called flower.  This is composed
of a small  quantity of mucilaginous  saccharine  matter,
soluble  in  cold water;  starch, which is scarcely soluble
in cold water, but  combines with that fluid by heat; and
an adhesive gray substance, insoluble in water, alcohol,
oil, or ether, and  in  many of its properties  resembling
animal substances.  When flour is heated with water, it
forms  a tough paste, containing these  principles verv
little altered,  and  not easily  digested by the stomach.
The action  of heat produces a considerable change  in
the ;gluten, and   probably in  the starch, rendering it 
130
BRO
more easy to be masticated as well as to be digested,
Hence, the first approach  to the making of bread con-
sisted  in parching  the  corn, either for immediate use as
food, or previous to its trituration  into  meal ; or else in
baking the flour into  unleavened bread, or boiling it into
masses more or less consistent; processes  sufficiently
indicated in the histories of the earlier nations, as well as
in the  various practices of the moderns.   It appears like-
wise from  the scripiures, that  the  practice  of  making
leavened bread is of very considerable antiquity; but the
addition of yeast, or the vinous ferment now so generally
used, seems to be of modern  dale.   Wheat  contains
much more gluten than rye  and other grain ; and this is
the reason  of the superior lightness of wheaten  bread ;
for during the fermentation or rising  of bread, much car-
bonic acid gas  is evolved, which would escape from a
mass of little cohesion ;  but  the  paste of wheat  flour,
being rendered cohesive  and elastic by the gluten, retains
the gas, which, in its endeavours to extricate itself, awellsr
the mass, and renders it  light and spongy, forming  bub-
bles or cavities in the interior of the  loaf.  And here it
may be proper to anticipate what would naturally  come
under  the  head of Fermentation.   If the  rising or fer-
mentation of bread be continued  too long, especially if
the air have access, the  acetous  fermentation will  take
place,  and vinegar will be produced.   This is the cause
of the  sourness of bread.  To remedy this, a solution of
the carbonate of potassa (pearlash) is sometimes kneaded
into the bread ;  the effect of  this alkali being  to  unite
with and neutralize the acid, forming an acetate of potash,
while the carbonic acid of the carbonate of potash, being
liberated from its base, renders the bread still more light,
in its efforts to escape.
   Bromic Acid.   Has little odour, an acid taste, reddens
powerfully litmus paper ;  it  resembles  iodic, chloric, an<* 
BRU
131
nitric acids ; that is, it consists of one proportion of bro-
mine, united with five of oxygen.
   Bromide.  This term is applied to certain salts which
result from the union of bromine with metals and some
other substances.  Bromine combines with them  in dif-
ferent proportions, forming proto and per bromides, as is
the case with iron.   Many of the  salts thus formed ap-
pear  in crystals, and  some are soluble in water and alco-
hol.  Their peculiar natures, however, have not been
fully  ascertained.  It will be sufficient  to mention the
existence of bromides of antimony, arsenic, barium, bis-
muth, calcium, carbon, glucinum, gold, lead, magnesium,
mercury, phosphorus, platinum, potassium, silver, sodium,
sulphur, tin,  and yttrium.*
   Bromine.   {Brome.)   From  bromos, fcetor, so  called
on account of its strong and unpleasant odour which re-
sembles that of chlorine.   It is highly destructive of ani-
mal life, and has been recently discovered by M.  Ballard,
a chemist of Montpelier, (France,) in the mother waters
of salt works, and in the  lixivia of the ashes of marine
plants.   It is a  liquid of a  deep red brown colour, very
volatile, and its vapour resembles in  appearance that of
nitric acid.   It boils  at 117° ; its density compared with
water is about 3.  It has extensive  chemical affinities,
forming acids  and salts, as well as  direct combinations
with metals.   Like oxygen, iodine, and chlorine, bromine
is attracted to the positive pole,  and  is therefore said to
be electro-negative.  It was at first  suspected that bro-
mine  might  contain  iodine ;  but experiments made by
Professor De La Rive prove the contrary.
  Brucine,  or  Brucia.   An alkaline substance of  a
pearly  white, similar to boracic acid; sometimes in  a
spongy mass, little soluble in water, insoluble in ether
;md fixed oil, but soluble in hot  and cold alcohol; sub-

  * For a more detailed account of these salts we refer to Prof. Green's excel
lent " Text-book of Chemical Philosophy.'" 
132
B  V  T
mitted to the action of fire, brucine is decomposed, giving
ammoniacal products.  It forms  with acids, acid  salts
and neutral combinations.   The sulphate, hydro-chlorate,
(muriate,) and oxalate of this base, crystallize in the neu-
tral state : the nitrate and the phosphate crystallize also,
but the acid must be in excess: the acetate is uncrystal-
lizable.  Brucine is very  bitter, notwithstanding its little
solubility.   It was discovered by Pelletie rand Caventon,
in the bark of  the Brucea anti-dysenterica;  it is there
united to  gallic acid.  It has  been  discovered in the
Strychnos ignatia, (bean of St. Ignatius,) and  the Strych.
nos nux vomica, (vomica nut.)   It is more easily obtained
from the brucea, this being the only alkali contained  by
the plant.  The process for obtaining brucine is  as fol-
lows :  a  strong  decoction of the plant is made with wa-
ter ; oxalic acid is added to this which takes the brucine
from the gallic acid ; the liquor is evaporated to an extract-
ive consistence ; the residue  is treated with cold alcohol,
which dissolves  all the matter except the oxalate of bru-
cine.   This salt is boiled with  an equal part of magne-
sia to decompose it.  The free  brucine is redissolved  in
alcohol, filtered in  order to separate the oxalate of mag-
nesia ; by a slow evaporation, the  alcohol deposites mi-
nute regular crystals.   This substance is very poisonous.
but less so than strychnine.   It is distinguished by a
property of becoming  of  a blood-red  when a few drops
of concentrated nitric acid are poured upon it.
   Butter.   {Beurre.)   A substance  usually lemon co-
loured, sometimes  whitish,  of  a soft consistence, and
agreeable taste, slightly aromatic, lighter than water and
very easily melted.  It soon  becomes rancid when ex-
posed to contact with  the air,  particularly in  summer.
When salted it  may be preserved for months.  It has
been  found only in  milk, from which it is easily extract.
ed.   The milk being left to stand a few hours, the cream
rises  and is taken  off with a skimmer.   By agitation in 
BUT                   133
u vessel called a churn the particles of butter unite, and
the cream is transformed into butter and buttermilk;  the
last  is serum  holding  in  suspension  some  butter and
caseous  or  cheeselike  substance.  The  butter is then
washed in a large quantity of water and put up in firkins
when designed  for  commerce.  Butter always retains
some caseous matter, which can be disengaged bv melt-
ing it; according to Chevreul, it is composed of stearine,
elaine, butyric acid, butyrine, and a  small  quantity of
colouring matter.   Very fine soap may  be  made with
butter.
   Butter of Antimony.   A name  formerly given to
the proto-chloride of antimony.  (See Antimony.)
   Butter of Arsknic.   See Deuto-Chloride of Arsenic.
   Butter of Bismuth.  See Chloride of Bismuth.
   Butter of Tin.   See Deuto-Chlorate of Tin.
   Butter of Zinc.   See Chloride of Zinc.
   Butyrine.  A substance very fluid at 68°, congealing
at 32° ; its odour is like that of melted butter ;  it is either
yellow or whitish, according to the kind  of butter from
which it is obtained.   Its density  is 0-908.   Chevreul
discovered this substance in butter, united to stearine,
elaine,  and butyric acid.   In order to obtain it, butter
which has been purified by fusion is for several uays ex-
posed to a heat of 67°.   The greater part of the stearine
is deposited  in  little crystalline grains.  The oily com-
pound is carefully  filtered,  then mixed  with an equal
part  of  rectified alcohol; this mixture is exposed to a
temperature of 67°, care being taken to shake it from
time to time; the alcohol is then decanted;  it is then
distilled, and the residue is an  oil rich in butyrine, which
is disengaged by the carbonate of magnesia.   The buty-
 rate formed is dissolved in water, alcohol is again brought
to act upon the remaining oily matter;  after evaporatinp
this solvent, nothing remains but pure butyrine.
                           12 
131
C A I
                         c.

   Cadmium.  A metal of a whiteness resembling  tin.
having  neither taste  nor  odour, more fusible than zinc.
easy to volatilize.   Oxygen has no effect upon  it at  the
ordinary temperature, but  if submitted to the action of
caloric, it burns  with  flame, and forms an  oxide of an
orange yellow colour ; it unites with most of the metals.
Among the combustible bodies not metallic, chlorine,
phosphorus, iodine, and sulphur are the only ones with
which it has been combined.  Cadmium has never  yet
been discovered  in a native state; it has been  found in
mines of zinc in the  state of a sulphuret  and an oxide,
but in very small quantities.  MM. Stromeyer and Her-
mann discovered this metal in 1818.   It is extracted by
dissolving with heat  Calamine in weak sulphuric acid,
saturating this solution by a  current of sulphuretted  hy-
drogen;  the sulphuret of cadmium, a little of the sulphu-
ret of zinc,  and sometimes sulphuret of  copper,  are
formed.   The different sulphurets are re-dissolved in
hydro-chloric  acid.   Sulphuretted  hydrogen is  disen-
gaged, and the chlorides of cadmium and zinc are formed;
these are evaporated to dryness.   The whole is dissolved
in water, an excess <tf the carbonate  of ammonia is  ad-
ded, the hydro-chlorate  of ammonia is formed, and  the
carbonates of zinc  and cadmium are  precipitated ;  the
carbonate of zinc is dissolved by the excess  of  the car-
bonate of ammonia, and that of cadmium  remains insu-
lated ;  the substances  are filtered, the precipitate washed
and dried ; this  with a mixture of lamp-black is heated
to redness in an  earthen retort.  The cadmium sublimes
in the  neck of the retort.   Its specific gravity is 8-64 ■
on account of its scarcity it is of no use in the arts.
   Cafpein.  {Cafeine.)  This substance has  by che-
mists  been regarded  as a salifiable base,  but it has  not 
C  A L
135
yet been sufficiently studied  to pronounce with certainty
upon its nature.  It is soluble in water, and is extremely
volatile.  It crystallizes in long needles of a beautiful
white.  This substance is extracted from coffee.
   Calamine.   A name given to  an ore of zinc,which
according  to Berzelius is a hydrated  selenite  of zinc,
mixed with the carbonate of the same base.
   Calcination.   Oxidation.   The  fixed residues of
such matters as  have undergone combustion, are called
cinders in common  language ; and  calces, or now more
commonly oxides, by chemists; and the operation, when
considered with regard to these residues, is termed calci-
nation.  In this general way it has likewise been applied
to bodies not really combustible, but  only deprived ot
some of their principles by heat.  Thus we hear of the
calcination of chalk, to convert it into  lime, by drawing
off its carbonic acid and water; of gypsum or plaster of
paris,  of  alum,  of borax, and  other saline bodies, by
which they are deprived of their water of crystallization ;
of bones, which lose their volatile parts by this treatment,
and of various other bodies.
   Calcium.  The metallic base of lime. The properties
of this metal are little understood ; it is however known
to take oxygen from almost  all substances, is destroyed
by contact  with the air,  has a specific gravity  greater
than water, and is brilliant like potassium.   This metal
is obtained by making a paste with the  sulphate of lime,
or any other calcareous salt, and placing this  paste  in a
vessel with  mercury upon a  metallic plate.  The nega-
tive wire of the pile is brought in contact with the mer-
cury, and the positive wire with the plate.  The sulphuric
acid  and oxygen go to the positive pole, and the calcium
to the negative,  where it finds the  mercury with which it
amalgamates.  This operation must be  long continued in
order to obtain  an amalgam which contains a little cal-
cium ; this  amalgam is introduced into a very small re 
136
C  A L
tort, with  some of the oil of naphtha, a small receiver
being fitted to the retort, the distillation is commenced.
The oil in vaporizing driving the air from the retort, part
of the mercury volatilizes,  leaving a small  quantity of
calcium retaining still a little mercury.
  Calculus. (A diminutive, from calx, lime stone.)  This
is a name  given to all hard concretions, not bony,  formed
in the bodies of animals.
  Calomel.  {Calomelas.   From kalos, good, and melas
black ; from its virtues and colour.)  Name for the Proto-
chloride of mercury.   (See this word.)
  Caloric.  (From color,  heat.)  It  is  an  invisible,
subtle, elastic fluid, which is  capable  of moving in the
form of rays.  It  is known in  three states :  specific, ra-
diated, and latent caloric.   Specific caloric is that which
different bodies  absorb, in  order to  rise  to  a  certain
number of degrees,  under a  given weight and a common
pressure.   Several  chemists have proved  that this ab-
sorption was relative to the bodies ; for example, that 1
pound  of  mercury at 32°, and 1 of water at 93-2°, gave
a mixture  at 91-4° ; then the quantity of heat which can
elevate the water 1-8°, can elevate the mercury to 91-4°.
  Radiated caloric is that which emanates from all  parts of
a heated  body, in  rays which traverse the air with the
greatest velocity.   If these rays fall upon a polished sur-
face, most of them are  reflected; upon a rough surface,
they are absorbed in  a much  greater degree, and the sub-
stance becomes sensibly  heated.   If two vessels  with
very smooth surfaces are exposed to the same degree of
heat, they remain at the same temperature : if the sur-
face of  one of them is made rough, it  will heat  by the
caloric radiated from the other.  If two concave mirrors
be arranged at the  distance of a  few feet  from  each
other, and  an ignited substance  placed in the focus of one
of these mirrors, the  heat  reflected from the opposite
mirror, will  be  sufficiently great to set fire to  tinder or 
C  A L
137
 sulphur, which being less  polished than the surface of
 the mirror, will absorb the calorific rays.
   Latent caloric  is that which forms a constituent part of
 bodies, and which does not affect the  thermometer; the
 fusion of metals, the resolution of ice into water,  prove
 the existence of latent heat.   If we take two pounds of
 pounded ice, or snow at  32°, and pour  upon  this sub-
 stance  2 pounds of water  at  167°,  we  shall  obtain  4
 pounds of water at  the temperature 32°.   The ice has
 then  rendered latent all  the caloric  of  the water em-
 ployed.  An essential property of caloric is its  tendency
 to maintain an equilibrium.   Every one knows that when
 two bodies of different temperature are brought in con-
 tact, the cold one gains  caloric at  the expense of the
 other, until the equilibrium is established ;  from thence
 result the two sensations known under the name of heat
 and cold.  Our organs may become habituated to these
 sensations until they cease to feel them ; bodies which at
 first seemed very hot or very cold, may cease to produce
 this effect.   Thus in caves where the temperature during
 the whole  year  is   at 50°,  it  seems  much warmer in
 winter, and colder in summer.
   Caloric moves through solid bodies with facility ; if the
 end of a rod of metal be put into the fire,  the other end
 will be almost immediately  heated.  If for the  metal be
 substituted wax, wood, or coal, the end distant from the
 fire will scarcely change its temperature, while  the other
 will be in a state of fusion ;  this fact proves that all bodies
 are not equally good conductors of caloric,  and that this
 property seems to diminish with density ;  for liquids are
 very bad conductors, and gases  seem to  have no power
 of conducting this fluid.   Wrhen boiling water is poured
 into  a vessel  containing  mercury, the  surface of the
 liquid will  be  very hot, while the bottom of the vessels
containing  the metal, will heat very slowly.  This ex.
plains why the water of seas and lakes is usually hotter
                         12* 
138
CAM
upon  the surface than some feet below.  Yet when a
liquid is placed in a vessel over a fire, it soon boils ;  the
particles of the liquid,  near the bottom and sides of the
vessel becoming heated, are lighter  than the other  par-
ticles, and rise to the upper part of the vessel; the other
particles becoming in their  turn  heated, rise  and  take
their place  in the same manner, and thus there is an as-
cending and descending current at the same time.
  Caloric by interposing between the molecules of bodies,
increases their volume, changes  those which were solid
to liquids, and those which were liquid to  gases ; but if
caloric is taken from these  molecules, they resume their
former state ; those which were driven apart, return to a
closer contact, and the caloric escapes on all sides.  (See
"La Physique de M. Biot," and " Les Memoires de MM.
Gay-Lussac et Dulong.")
  Calorimeter.  An  instrument invented by De  La
Place and Lavoisier, to ascertain  the specific  caloric of
bodies.  It consists of three concentric vessels of copper
or tin,  the interior one of net work of iron wire ;  the
whole is covered with two  concave perforated valves.
The internal vessel is to contain the body to be examined ;
the  intermediate and outer one to be filled with pounded
ice.   The exterior  one serves only to secure the  other
irom the action of the surrounding air ; according to the
quantity of water found in the middle vessel, is known the
quantity of caloric which the body has furnished in order
to bring the ice to a liquid state.   The water is  conveyed
off  by means  of a stop-cock, with which  the  two  outer
vessels are supplied.
  Calx. {Calx, calcis, from the Arabian kalaji to burn.)
Chalk.  Limestone.  From this term is derived the word
calcareous, which signifies containing  lime.
  Camelion Mineral.  A combination  of potash with
the  per-oxide of manganese.  This composition is due to
Scheele, who discovered it  by calcining the nitrate  of 
CAM                   139
potash with the per-oxide of manganese.   Having dis-
solved in water the compound which he obtained, he saw
that the solution which was at  first given, took different
shades ;  it became blue, then changed to violet, and then
to red, and at length became colourless; acids changed
the green  to rose-coloured,  while  alkalies  changed the
green to red ;  on account of these changes of colour, this
substance  received the name of camelion.   This com-
pound is obtained by calcining a mixture of equal parts of
the oxide of manganese and potash, when it is wished to
form a camelion which would at once colour water green :
but in order to colour  red or purple, more of manganese
must be added.  The latter camelion dissolved in water, is
permanent, and may be crystallized in  needles of a dark
purple.   These acicular crystals have  a sweetish taste ;
they are unalterable  by the air, and possess  in a high
degree  colouring  properties.  Nitric  acid  decomposss
their solution ; mixed with sulphur,  phosphorus, and ar-
senic, they inflame spontaneously.   According to MM.
Chevillot and  Edwards,-(A/ra. de Chim. et de Phys.) the
camelion appears  to be  a manganesiate of potash;  for
there  is  evidently an  absorption of oxygen  during its
formation.
   Camphor is a peculiar vegetable substance, of a trans-
parent white when purified,  breaking easily, of a strong
but agreeable  odour; its taste is acrid and pungent; it*
specific gravity 0-9887.  Camphor is not decomposed by
the air ; yet in time it wholly disappears.  This is owing
to its vaporization, and not to decomposition.   It is easily
dissolved in alcohol; is soluble in ether, the fixed and vo-
latile oils, acetic and nitric acids ; it burns like  the essen-
tial oils, producing  an abundant black smoke.   It is, for
commerce, extracted  from the Laurus camphora, a tree
which grows  in  Japan and  the East  Indies.   For this
purpose the wood  is cut into small pieces, and distilled 
110
CAN
 with water, in large iron cucurbits, with  earthen  heads
 filled with  rice straw.  The camphor carried upward by
 the vapour of the water settles upon the straw,  in the
 form of greenish, pulverulent  masses.  It is transported
 in this state to Europe, where, in order to refine and pu-
 rify it, it is pulverized and  mixed with quick lime.  M.
 Proust obtained a crystalline product from many labiate
 flowers, which he  supposes differs  little  from camphor.
 According  to Saussure, camphor is composed of 74-38 of
 carbon, 10-67 of hydrogen, 14-61  of oxygen, and 0-34
 of  nitrogen.   Thompson  has  given a  very  different
 analysis.
  Camphor, Artificial.  A white crystalline substance,
 having  some analogy to camphor  in smell and also in
 dissolving in  ether and alcohol ; it is lighter than water,
 burning without any residue, not reddening litmus.  This
 product was discovered by Kind, by saturating  the es-
sence of turpentine with one third of its weight of hydro-
chloric (muriatic) acid gas.
  Camphorates.  Combinations of camphoric acid with
salifiable bases ;  these salts are little known ; only those
of ammonia, soda, potash, barytes, and lime, have been
obtained; they are all decomposable  by fire ; and  ac-
cording to  M.  Bouillon-Lagrange  the  acid  volatilizes
without alteration, yet Bucholz, in decomposing the cam-
phorate of lime, obtained acetic acid and oil.  The cam-
phorates are the products of art, and are prepared by a
direct process.
  Cantharides.   Musca Hispanica.  Commonly called
 Spanish flies;  Lytta  Vesicatoria, or the  blistering fly.
These flies  have a green, shining, gold body; they are
common in Spain, Italy, and other parts of the south of
Europe.  The cantharides  have  been the  object of the
researches  of many  chemists,  the  most  successful of
whom in this investigation are  MM. Beaupoil and  Robi. 
CAR
141
 quet.  The last has succeeded in extracting the pure blis-
 tering substance ; he also obtained a green oil, a yellow-
 ish and a black substance, acetic  acid, nitric  acid, and
 some  phosphate of  magnesia; the active substance  of
 these insects has been called cantharadin.
   Caoutchouc.  Indian Rubber.   Elastic Gum.  A solid
 substance, white when pure, without taste or smell, soft,
 flexible, very tenaceous  and elastic.  It melts easily,
 produces on distillation a little ammonia ;  burns readily,
 leaving very little residue ; it  is unalterable  by the air,
 and insoluble in water, alcohol, the alkalies and  acids.
 M. Pelletier has found, that ether will dissolve it in  small
 proportions.   The volatile oils are  the true solvents of
 this substance. It is extracted  from the Jatropha elastica,
 Urceola elastica, and other trees of hot countries.*
   Caphopicrite. * A name given  by M.  Henry to the
 colouring matter of rhubarb.
   Capsule.   Segment of a hollow sphere,  principally
 used  for  the  concentration and vaporization of liquids.
 The bottom is sometimes round, sometimes flat; capsules
 are made of platina, silver, lead, porcelain, and glass:
 the last are  little used.
   Caput Mortuum, or Terra Damnala, a name  given
 by the ancient chemists to the fixed residues which re-
 mained in the retort after disuuation; being, as they sup-
 posed, absolutely worthless.
   Carbo.   (From Charbah, a Hebrew word signifying
 burnt or dried.)  Coal.
   Carbo-Muriates.   (See Chloro-Carbonates.)
   Carbon.    {Carbone.)   Is a simple substance which
enters into the composition of  all vegetable and animal
matter; it is  one of the  most extensively diffused sub-

 * A similar substance is said also to have been obtained from the juice of an
 \merican species of Jlsclepias, or milk weed. (See " Familiar Lectures on Bo
iany," page 70.) 
14^
CAR
 stances in nature.  Pure  carbon is solid, inodorous,  in-
 sipid, and insoluble.  That which  is derived from the
 combusdon of wood is black, porous, and easily reduced
 to powder;  but  in this state  it  is mixed with metallic
 oxides,  salts, &c. ;  in the  anthracite  coal it is much more
 pure.   It is sometimes found crystallized, in which state
 it constitutes the diamond, a substance so hard as to cut
 all others, while  itself can  be cut by none. Diamonds are
 usually  limpid, sometimes without colour, sometimes rose
 coloured, brown, blue, yellow, or green. The most intense
 action of fire has no effect upon carbon, but it burns in
 oxygen gas  at a very high  temperature ; it is necessary
 that the intenseness of the heat should be greater in pro-
 portion  to the density of the carbon.   Carbon combines
 but  with  few combustible bodies.  One  of  its  most re-
 markable properties is the avidity with which it absorbs
 different gases.  The purest inflammable part of char-
 coal is what is usually called carbon ; this united  to oxy-
 gen  forms carbonic acid.  (See the word.)  For the me-
 thod of obtaining charcoal, see the article Wood.
  Carbonates,  Dotjrle.   The carbonate of lime unites
 with the carbonates of iron and magnesia, forming dou-
 ble carbonates;  that  of lime and magnesia  is known  by
 mineralogists under the name of dolomite.
  Carbonates,  Neutral.  These salts  differ  from the
 sub-carbonate in containing double the quantity of car-
bonic acid;  they easily crystallize, giving a green tinge
to blue vegetable colours ; they have little taste ;  that of
ammonia, according to Berthollet, is without  smell.  Ex-
posed to the action  of fire they disengage a  part of their
acid, and become  sub-carbonates.   The air does not
affect them.   They effervesce  with  acids, and precipi-
tate most  of the soluble salts in the state of sub-carbon-
ates, disengaging a part of the carbonic acid.
  The following is the process for obtaining the neutral
 carbonates of soda,  potash, and ammonia; carbonic acid 
CAR
143
is slowly added to a solution of their sub-carbonates, and
gradually as  saturation takes place,  the  salt becoming
less soluble, crystallizes.  It is then  easy to separate it
by decantation from the sub-carbonate which is not satu-
rated ;  this preparation requires  much  time in order to
obtain a small quantity.  According to Thenard the neu-
tral  carbonates are composed as follows  : that of potash,
100 of the acid and 106-686 of the base,  that of soda, 100
of the acid  and 70-693 of the base.
   Carbonates (Sub.)  All these salts, except those of
potash, soda,  barytes,  and  perhaps lithia, are more or
less easily decomposed by fire ;  the  acid becoming en->
tirely disengaged, the residue is the oxide of the metal,
or the metal itself, if it is of the  series of those which
have little affinity for oxygen.  Only the sub-carbonates
of soda, lithia, and  ammonia are soluble in water ;  many
others dissolve in an excess of acid, such  as  lime, mag-
nesia, &c.   All the acids  except the  hydro-selenic, the
hydro-sulphuric,* and the hydro-cyanic, decompose the
subcarbonates, uniting to their  bases and disengaging
their acids ; all the subcarbonates, except those of pot-
ash, soda, and lithia,  which are soluble,  are prepared by-
double decomposition ;  many are found in nature.
   Carbonate (Sub)  of  Ammonia.   A  white caustic
salt; it greens the infusion  of violets,  vaporizes   gra-
dually in the air, is soluble  in cold water, and  gasifies
when dissolved in boiling water.   It is obtained  by put-
ting  equal  parts of the sub-carbonate of lime and the
hydro-chlorate (oxymuriate) of ammonia into a stone re-
tort ; the two  salts decompose each other, forming the
chloride of calcium and the carbonate of ammonia;  the
latter being volatile passes into a large receiver attached

  ' Hydro-sulphuric aoid is used by the French chemists to designate sulphu-
retted hydrogen. 
144
CAR
 to the apparatus, and which is  kept  cool by cloths wet
 with cold  water.   The  sub-carbonate  of ammonia ap-
 pears to be formed of 100 of ammoniacal gas in volume,
 and 50 of carbonic acid.   It has  been called English
 Volatile Salt.
   Carbonate (Sub) of  Baryta.   It is found in nature,
 principally in  England.  It is insoluble in water, and
 dissolves in nitric acid without effervescence.   Accord-
 ing to Clement, it is composed of 78 of baryta and 22 of
 carbonic acid.
   Carbonate  (Sub)  of Lime.  {Carbonate {Sous)  de
 Chaux.)  This salt is of all others in nature,  the most
 abundant;  forming in various parts of  the earth, exten-
 sive  ranges of mountains.  Marble, alabaster, stalac-
 tites, stalagmites,  most  kinds of building stones,  litho-
 graphic  stones, &c. &c, are only carbonates of lime in
 different states; it is sometimes found  crystallized, and
 in this state presents various forms of the obtuse rhom-
 boid, of  which the great angle at the summit is  105°.  It
 is decomposable by fire,  and by most of the  acids, and is
 found in nature so pure,  as  to render its preparation by
 an artificial process unnecessary.
   Carbonate of Copper.   {Carbonate de Cuivre.) This
 salt naturally forms upon the surfaces of copper vessels
 exposed to  contact with the air.  In nature it is found in
 different states; sometimes brown, composed of 78 of the
 oxide of copper and 22 of carbonic acid ; it contains no
 water, and is therefore  called  anhydrous; sometimes it
 is green, compact, or earthy, crystallizing although rarely
 in rhomboidal prisms, and containing in 100  parts,  72 of
 the oxide of copper, 20 of carbonic acid, and 8 of water.
 This  is known by the  name of malachite.  There is
another carbonate of copper, which  is of  a beautiful
blue, frequently crystallized in oblique rhomboidal prisms.
and containing in 100 parts, 69 of the oxide of copper, 26 of 
C  A R
145
carbonic acid, and 5 of water.  These different carbon-
ates are by the mineralogist considered as distinct species.
   Carbonate (Sub) of Iron.  {Carbonate Sous de Fer.)
It exists in nature, in masses and in veins.   It  varies
from a yellowish white to a brownish colour, and is some-
times found  regularly  crystallized.   In  the  arts it  is
prepared by decomposing the sulphate  of iron, by a solu-
tion of the sub-carbonate of potash or soda.  In order to
obtain a sub-proto-carbonate or sub-deuto, &c, it is ne-
cessary to employ a salt  of iron which is at the first or
second degree of oxidation, according to the salt desired :
the precipitate must  be washed, dried, and preserved in
bottles well corked, that it may not pass to the last degree
of oxidation, by absorbing oxygen from the atmosphere.
   Carbonate (SuB)of Lead.  {CarbonateSousdePlomb.)
It  is found in beautiful acicular  crystals, transparent, of
a brownish yellow ; it is very  rare in nature.  The sub-
carbonate is of frequent use in the arts, where it is known
under the name of ceruse, whitelead, <Sfc.  It is procured
for use in commerce by introducing a current of carbonic
acid gas  into a solution  of the sub-acetate of lead ; the
sub-carbonate of lead which is thus formed  is precipita-
ted.   Another very  ancient process is to put  plates of
lead rolled  spirally into  earthen pots containing vine-
gar ; these pots  are placed under the ground; at the close
of two  months,  being   uncovered,  the  plates of lead
are found almost entirely  converted into sub-carbonate of
lead and a  small quantity of the acetate;  the  latter is
separated by washing ; all  the acetate of lead dissolves,
and the sub-carbonate is precipitated.
   Carbonate (Sub) of Lithia.  This salt is white, pul-
verulent, little soluble in water,  strongly alkaline, unde-
composable by fire, and unalterable  by the air ; it is the
oroduct  of art, and  obtained  in  the following manner :
 Vcetateof barvtes is poured  upon a solution of sulphate
                          13 
146                    C A R
of lithia, the sulphate of barytes is precipitated, and the
acetate of lithia remains dissolved.  The liquor is evapo-
rated to dryness, and the acetate of lithia is decomposed
in a silver crucible ;  a formation of the  sub-carbonate of
lithia and of carbon ensues ; it is only necessary to lixi-
viate and to evaporate it in order to obtain the  pure sub-
carbonate.
  Carbonate  (Sub) of Manganese.    It is sometimes
of a pearly whiteness, sometimes rose coloured, is found
in nature combined with  the sub-carbonate of lime or
iron  ; it is obtained in the same manner as the sub-car-
bonate of copper, iron, &c.
  Carbonate (Sub) of  Magnesia.  This substance ex-
ists in nature, but not pure, being mixed with lime, silex,
&c.   It  is frequently prepared in the arts, and is  then
very white, light, pulverulent, and  greens the infusion of
violets.   It is decomposable by fire.  In order to prepare
it, a  solution of  the sulphate of magnesia should  be
poured  upon the sub-carbonate of potash ;  an  abundanl
precipitate  is  formed, which is  separated by  filtration:
this is  carefully washed to separate it from the sulphate
of potash, and then left some days to drain.   When  it
begins to acquire some degree of consistence it is put into
little square boxes, where the drying is completed.  It is
prepared in such a manner as to be as light as possible.
  Carbonate (Sub) of Potash.   A very  soluble salt,
deliquescent, giving  a strong green tinge to  vegetable
blues, of an acrid, caustic taste, not decomposable except
by the strongest heat.  It is not found in nature.   By
incinerating vegetables, and lixiviating their ashes, all the
potash of commerce is obtained ; it is always mixed with
a little of the sulphate of potash, and the chloride  of
potassium ;  besides these substances, it  contains a little
of silex, the  oxides  of  iron and manganese ; the latter
often gives it a green colour, forming a  sort of  camelion.
In countries where wood is abundant, as in Russia, some 
C  A l;
141
parts of America, &c, in order to obtain this carbonate,
vcgiiahles  are  burnt  upon  the  ground, the ashes are
formed of the sulphate of potash, chloride of potassium,
(all  soluble salts,) alumine, silex? oxide  of iron,  manga-
nese, iime, and  the sub-phosphate  of lime  ; a little car-'
bon  escapes from the combustion, and a  great quantity of
the sub-carbonate of potash ;  these ashes are evaporated
to dryness, and the residue  called saline is  placed in re-
berberatory furnaces, where  it is  strongly  calcined,  in
order  to  incinerate the little  carbon which can have
escaped combustion; after Ix>ug left to  cool it is put up
in close  barrels ; this  substance is  used in commerce
under the name of potash.   This is  impure, and as it is
difficult to  purify it completely, the sub-carbonate is ob-
tained by decomposing at  a red heat a mixture of the
nitrate of poiash (saltpetre) and the tartrate of potash,
lixiviating  the product and evaporating it  to  dryness.
According to  VI.  Guibourt, this salt often  contains the
cyanuret (cyanide) of potassium ; this is the case  when
the heat has been raised too high.
   For  use in the arts,  are burned the dried  lees of wine,
which contain much of the tartrate of potash ; the  alkaline
residue is called cendres gravelfes.  If the sub-carbonate
of potash is left  exposed to  the  air, it attracts moisture,
and  soon becomes a  liquid of an oily  consistence, for-
merly  called Vhuile de tartare par defalliance.   M. Stru-
boni {Ann.  de Chim. et de Phys.) has succeeded  in crys-
tallizing  the sub-carbonate  of potash in sharp acicular
crystals.   M.  Vauquelin,   having  analyzed the  sap  of
many vegetables, and never  having  found  the  sub-car-
bonate of potash, concluded that this is  obtained only by
the  decomposition of  the acetate,  malate,  tartrate, oxa-
late, and nitrate of potash, which are frequently found in
vegetable substances.
   Carbonate (Sub) of Soda. {Carbonate sous de Sonde.)
 This salt, existing in beautiful quadrangular prisms, con- 
148
CAR
 tains 62-69 for 100 of the water  of crystallization; it i>
 efflorescent, sharp, caustic, alkaline, more  soluble in hot
 than cold water.   Fire at first produces the watery,  then
 the ignited fusion, which, like the preceding, it  supports
 without  undergoing any decomposition.   The  sub-car-
 bonate of soda exists in many places, either in solution in
 the waters of  certain  lakes, or upon the  surface of the
 earth, as in Egypt, Hungary, and America ; but is never
 found pure.   It is called, in this impure  state, natron.
 Some plants which grow upon the borders  of the  Medi-
 terranean furnish  soda,  such as the mlieornia, statica,
 atriplex,  &c.   These  plants when in the highest state of
 perfection  are burned;  the product of the combustion,
 which is in greenish  masses, contains many heteroge-
 neous substances, and is sold in commerce  under differ-
 ent names, according to the countries from whence it is
 brought.  The sodas of Alicant, Carthagena, Narbonne,
 and Normandy, are the  most known.   They contain in
 this  state sub-carbonate of soda, sulphate  of soda, sul-
 phuret of sodium, muriate of soda, sub-carbonate  of lime,
 alumine, silex, oxide  of iron, charcoal, and sometimes
 the iodide of sodium.
  In order to prepare a more pure sub-carbonate of soda,
 a mixture is made of 180 parts of dry sulphate  of soda.
 180 of powdered chalk, and 110 of the dust of charcoal:
 this mixture is put into a reverberatory $irnace of an ellip-
 tical form, the temperature of which is  above that of red
 heat; in a quarter  of  an hour the  substance  becomes
 clammy ; it is then put in kettles, and cold  water poured
 upon it;  all the carbonate of lime formed by the decom-
 position of the  chalk dissolves, while tho sulphuret being
insoluble when cold is not affected; the different waters
 of the lixiviations are  united, evaporated to dryness, and
exposed to the air, in order that the soda, yet very caus-
 tic, may  pass to the state of a sub-carbonate ; at the end
of fifteen or twenty days, if the salt effloresces, it is  lixi. 
                       CAR                   14g

 viatcd anew ;  after suitable evaporation, the liquor is left
 to crystallize  by cooling.   This salt was formerly called
 salt of soda, or crystals of soda.
   Carbonate (Sub) of Strontian.  This salt being of
 no use  is never  prepared in  the  arts, but is  found in
 nature ;  it possesses  properties very similar to the  car-
 bonate of barytes.
   Carbonate (Sub) of Zinc  It is found with calamine
 in  zinc  mines, in  the form of  little crystals or in small
 lamellar masses.   It can be artificially obtained like the
 sub-carbonates of  lead and iron.
   Carbonates  (Sub) with double excess  of base.
 These combinations contain twice as much of the bases,
 or a less quantity of the acid, than  the sub-carbonates  ;
 such as the malachite,  and the mortar of old buildings.
  Carbonic Acid.   See Acid Carbonic.
  Carbonic Oxide.   See Oxide of Carbon.
  Carbo-Sulphuret.  A term applied by Berzelius to
the compounds formed by the union of the bisulphurets of
carbon with the alkalies.
  Carburets.   {Carbures.)    Combinations of  carbon
 with simple bodies.
  Carburet of Chlorine.   See Chloride of Carbon.
  Carburetted Hydrogen (Deuto.) {Hydrogtne Car-
bone.)   A gas of a  bituminous odour, colourless and insi-
pid ; it docs not support combustion.  Its density (taking
a medium from the analyses of  many chemists) is -9816.
This gas exposed to different degrees of heat loses most
of its carbon, increasing gradually in volume  according
to the  intensity of the caloric ;  submitted to the highest
temperature, it is increased 3 times in volume.   Oxygen
o-as and atmospheric  air have  at  the  ordinary tempe-
 rature  no action upon it; but if the temperature is  ele-
 vated,  and the oxygen in excess, combustion takes place,
 producing water and carbonic acid.
                        13* 
150
CAR
   If a mixture of carburetted hydrogen  and oxygen in
 suitable  proportions is inflamed under a glass vessel, a
 detonation takes place, more violent than can be produced
 by hydrogen alone.  Carburetted  hydrogen gas may be
 decomposed by a series  of electric  sparks, and all  the
 carbon will be deposited on the sides of the  vessel.   It is
 little soluble in water.  Chlorine produces various effects
 upon this gas :  when a mixture of the gases is inflamed,
 either by the solar rays or otherwise, it  suddenly deto-
 nates, is  transformed into hydro-chloric acid, and carbon
 is deposited; but  if this mixture remains  exposed to a
 diffuse light and at the ordinary temperature, it forms an
 oleaginous compound, called  hydro-carburet of chlorine
 {hydro-carbure de chlore.)  Iodine  forms  a combination
 known as the hydriodide of carbon, {hydrwdure de carbone.)
   Carburetted hydrogen gas is never found  in nature • it
 is procured by submitting in a retort, at a mild heat, 1 part
 of alcohol and 4 parts of sulphuric acid ; a tube fitted  to
 the retort is placed  under bell-glasses filled with water-
 the alcohol soon decomposes, and  hydrogen, which is the
 result of this decomposition, is disengaged ;  a small quan-
 tity of sulphurous  and carbonic   acids i,  formed, and a
 little  carbon deposited; the gas is purified  by shaking it
 with a little potash-water.  It is composed of 2 volumes
 of hydrogen and 2 volumes of  the  vapour of carbon.
 This substance  which was discovered by the chemists of
 Holland, was by them called olefiont gas.  For purposes
 of illumination, a gas resembling  it  but containing more

 ^urelted'h f" *"?" ^"^ th&n this"  *>«*>-
 carburetted  hydrogen is  obtained by distilling at a hiffh
temperature oils, oily seeds, and  especially coal.  Sfe
Thonw, Chemigtry> for the     cuiarg  y         e
ject.
caXuretted ZT    *   g 1™ beHeved that th* deuto.
carburetted hydrogen was that compound  of hydro**,, 
CAR
15J
and carbon which contained this latter combustible in the
greatest  proportion;  but  it has been  ascertained that
when these two bodies are found in favourable circum-
stances, they combine so as to form a gas which contains
1 times as much carbon as the proto-carburetted hydro-
gen, and of course twice as much as the deuto-carburet-
ted : this takes place when oleaginous seeds are decom-
posed at a temperature not too elevated ; for as the deuto-
carburetted hydrogen decomposes at a high temperature.
much  more does  the per-carburetted, which  contains
more carbon, decompose at the same temperature.  It is
easy to imagine its  properties after understanding those of
the deuto-carburet.  On account of the  intensity of its
flame, which is owing to its great quantity of carbon, it is
very successful^ used for  lighting streets, houses, &c.
   Carburetted Hydrogen.  (Photo.)   Insipid, of a
disagreeable  odour similar to the preceding ; its density
is  0.9716 ;  mixed with oxygen or atmospheric  air, it  de-
tonates like the preceding gases; it burns with a pale
yellow flame ; chlorine  decomposes it at a  red heat,  but
has no action upon it at the ordinary temperature.   This
gas exists in marshes, and at the bottom of stagnant wa-
ters, rising up in the form of bubbles ;  it  is produced by
the gradual  decomposition of vegetables.   It is common
in the galleries of coal  mines, and, before the discovery
of Davy's safety lamp, rendered the working of them very
dangerous.   This gas gives rise to the meteors which  are
observed upon  the declivities of the Apenines in Italy,
and which are often seen in  marshy places in damp and
warm weather.  It may be obtained  by inverting vessels
filled  with  water  over the  mud  of stagnant  pools  or
ditches ; on stirring the mud, the  gas rises into the ves-
sels.
   Carburet of Chlorine-   {Carbure de Chlore.)   Sec
 Chloride of Carbon. 
152
C  A R
  Carburet of Iron (per.)  {Carburede Fer.) {lilaci,
Lead.)  Plumbago.  A shining substance of a dark gra\
colour, unctuous  to the touch, leaving stains  upon sub-
stances against which it has been rubbed.   It is  easily
cut with a knife, and by rubbing acquires a metallic bril-
liancy. It is found in nature in primitve countries. Plum-
bago  appears to be  formed of 92 ot carbon, and 8 of
iron.
  Carburet of Iron (Proto.)   See Steel.
  Carburet of Sulphur.   Sulphuret of Carbon.  Alco-
hol of Sulphur.  A liquid colourless compound, of a livels
and penetrating odour, and a caustic taste.  Exposed to
the air, it  vaporizes wi-hout decomposition,  inflames at
the approach of a burning substance, giving rise to sulphu-
rous and carbonic acids, and a light  deposite of sulphur.
Water has  no action upon the carburet of sulphur ;*it is
dissolved by  alcohol, ether, and the fixed and  volatile
oils.  The carburet of sulphur is prepared as follows :
Thoroughly calcined charcoal is to be put into a porce-
lain tube, that traverses a furnace at a slight  angle  of in-
clination ;  to  the higher end of the tube, a retort  of glas:-
containing sulphur, is luted;  and to the lower end  is at-
tached an  adopter  tube, which enters into a bottle with
two tubulures, half full of water, and surrounded with
cold water or ice.   From the other  aperture of  the bot-
tle, a bent tube  proceeds into  the  pneumatic  cistern.
Heat  being applied, the sulphur fuses, and is reduced to
vapour; this, meeting  with the charcoal, combines with
it, and forms a carburet of sulphur  which condenses in
the porcelain tube.   This compound was discovered by
Lampadius ; according to M. Vauquelin 100 parts of the
carburet of sulphur are formed of 14.15 of carbon, and
from 85 to  86 of sulphur.
  Carmine.   A lively red substance, granular, crystal-
line, unalterable by the air.  Fusible at 122",  destructi-
ble  by iodine  and chlorine ; decomposable by concern 
CAR
153
 irateil sulphuric, nitric, and hydro-chloric acids ;  veryso-
 ble in water, and little soluble in alcohol, insoluble in the
 fixed  and volatile oils, and  in  ether.'  The  acetate of
 lead, hydro-chlorate  (oxymuriate) of tin,  and nitrates of
 mercury disturb this solution.   Pelletier  and Caventon,
 in analyzing  cochineal, thus obtained this substance :
 After macerating pounded cochineal in ether, and het-a
 ing to the boiling point, they continued to renew the ether
 until all the oily matter was removed.   This cochineal is
 afterwards, with  some  alcohol, put into Chevreul's  di-
 gester; the digestions are repeated, and the liquid is left
 to spontaneous  evaporation.   The carmine thus obtained
 still  contains oily matter, which is separated by treating it
 with highly rectified  alcohol;  this dissolves only the car-
 mine and the oily matter  without attacking the  animal
 matter. Ether is then added, the mixture is disturbed, and
 the carmine deposited in the form of little briliant grains,
 while all the oily matter remains in  alcoholic ethe r.
  Carthamine.  The properties of this  substance are
little  known;  it is of a very  deep  red  colour, insoluble
in water  and alcohol;  acids render  the colour more
lively, and potash  and soda dissolve it, giving it a yellow
tinge.   It is  extracted  from  the Carthamus tinctorius.
 (Rouge is prepared from the Carthamus.)
  Cathartine.  A  substance which has been obtained
from senna, and which is  said to contain  the cathartic
principle of this plant.
  Cartilage.  An elastic, semi transparent,  animal so-
lid, which affords one third the weight of the bones, when
the calcareous salts are  removed by digestion in  dilute-
muriatic acid.    It resembles coagulated albumen.   Nitric
acid  converts  it into gelatine.   With alkalies it forms an
animal soap.  Cartilage is the primitive paste, in  which
the calcareous salts are  deposited in the young  animal.
 In the disease rickets, the earthy matter is withdrawn b\
morbid absorption, and  the bones  return into the  state 
154
C  E R
nearly of flexible cartilage.  Hence arise the distortions
characteristic of this disease.
   Caseum.   A white  substance  almost  without  taste ;
inodorous, heavier than water, without action upon vege-
table  blue colours.  This substance is decomposed by
fire, and furnishes much ammonia and carbon difficult to
incinerate.   It  decomposes by exposure to the air, a re-
action among the principles takes place, and it undergoes
a sort of putrefaction.   The caseous matter is insoluble
in water; but alkaline  solutions, particularly ammonia.
easily dissolve it.   Most acids produce the  same effect.
In order to obtain pure  caseum, milk  should  stand until
coagulated ;  the cream should then be taken off, and the
residue washed with a large quantity of water.
   Caustic   Lunar.   Fused  nitrate  of silver.    See
nitrate of silver.
   Causticity.  All substances which have so strong a
tendency  to  combine with  the  principles of organized
substances, as to destroy their texture, are said to be caus-
tic.   The chief of these are the concentrated acids, pure
alkalies, and  the metallic salts.
   Cement.   Whatever is employed to unite things of the
same  or different kinds, may be called a cement.  In this
sense it includes lutes, glues, and solders of every kind;
but it  is more commonly employed to purify those whose
bases are an earth or earthy salt.
   Cerasin.  The name  given  by theyPrussian chemist
Dr. John, to those gummy substances which swell in cold
water, but do not  readily dissolve in it.  Cerasin is solu-
ble in boiling water, but  separates in a jelly when  the
water  cools.   Water acidulated  with sulphuric, nitric.
or muriatic acid, by the aid of a gentle heat, forms  a per-
manent solution of cerasin.   Gum tragacanth is the best
example of this species  of vegetable product.
   Cerin.   {Cerine.)  An oily substance  analogous to
wax extracted by Chevreul from wax; this substance \>
Mttle known. 
C  11 A
155
  Cerium.  A solid metal, brittle, lamellar, of/ a green-
ish white, very difficult to melt, volatilizing at a high tern-
perature.   This metal was in 1804 discovered by Berze-
lius and  Hisinger, and afterwards investigated by Vau-
quelin and  Klaproth.  It is very rare, and  only found
'•ombined with silex, the oxide of iron, or with lime, alu-
mine, lluoric acid and yttria.  It is extracted by treating
in a crucible its purified  oxide with  charcoal, at a hio-h
temperature.
  Cerulin.   A name given  by Mr.  Crum to indigo
when rendered soluble  in water by exposure to strong
sulphuric acid.
   Ceruse.   A name given in commerce  to the  sub-car-
bonate of lead or white lead.
  Ceruse of Antimony.   Some ancient chemist  gave
this  name to  the pearly  matter which is separated  by
washing the diaphoretic antimony
  Cetine.  A name  given by Chevreul to a white sub-
stance soft to  the touch, brittle,  insipid, very fusible, and
volatile in a vacuum.  It is extracted from spermaceti, of
which it constitutes the greater  part; in order to obtain
it, spermaceti  is heated with boiling alcohol; on cooling
the mixture, cetine is deposited in the form of very light,
lamellar crystals.   Cetine vaporizes without forming glv-
cerinc ; the products of the saponification are composed
of ether,  margaritic, and oleic acids.
   Chaleur.  See Caloric.
   Ciialumeau.  See Iiloir Pipe.
   Champignons.   See Mushroons.
   Chalk.  See Carbonate of Lime.
   Charcoal  Animal.    {Charbon Animal.)  A black,
carbonated, and very friable  substance, is obtained  by
burning  animal substances, particularly bones,  in close
vessels.   It is purified by washing in hydro-chloric  (mu-
riatic) acid, in order to take away a portion of the lime,
which is  formed by the  decomposition of the carbonate 
15(5
CHI,
 of lime contained in the bones.  It possesses a high
 power of discolouring substances, and  is much  used in
 refining sugar.
   MM.  Bussy and Payen have, (in  a  memoir proposed
 for a prize  subject by the school of pharmacy,) proved
 that the discolouring  property was  inherent in charcoal,
 und that it was greater in proportion as the charcoal  by-
 its minute subdivision offered more surface;  that animal
 charcoal was better  for this  use, only because the ani-
 mal matter  isolated every molecule, and being destroyed
 by carbonization, prevented their union.
   Charcoal of Wood.   See Wood and Carbon.
   Charcoal Mineral.   See Coal.
   Chaux.  {Lime.)  See Oxide of Calcium.
   Chyazates.  See  Hydro-Ferro-Cyanates, and Ferru-
 retted Cyanides.
   Cheese.   Milk consists of butter, cheese,  a saccha-
 rine matter  called sugar of milk, and a small quantity of
 common gait, together with much water.
   Chemistry.   {Chimie.)  The  name  given to that
 science which has for its object a knowledge  of the ac
 tion molecular and reciprocal, which bodies exercise upon
 each other.  Chemistry  is of  ancient  origin, but it is
 only at the present day, that it  has  merited the name of
 science.   It has  risen from  the ruins of  alchymy; the
 alchymists having in their efforts to  arrive at their grand
 discovery, {grand ceuvre,) developed the first principles of
 chemistry.
   Chlorates.*   Combinations of chloric  acid with sali-
 fiable bases.   All the  salts which result from this combi-
nation, are decomposed by fire;  those of the  first sec-
tion are  transformed into oxygen and chlorine, and the
oxide of  the metal; all the others, except the chlorate of
ammonia, into a chloride  and oxygen, and according to
* Formerly called hyper-ozygcnated muriates. 
CHL
157
Vanquelin, a small quantity of  chlorine.  All the chlo-
rates, except that of mercury, are soluble, and not acted
upon by solutions of silver.   All the strong acids decom-
pose them, exhibiting  various phenomena, according  to
the degree of heat employed.
   Sometimes oxygen and chlorine are disengaged, some-
times the oxide of chlorine and oxygen.   This species of
salts was discovered by Berthollet;  they are all the pro-
ducts of art.
   Chlorate of Ammonia. Hyper-oxymuriate of Ammonia.
According to Vauquelin  it is obtained by pouring a solu-
tion of  sub-carbonate of ammonia into chloric acid, and
slowly  evaporating  the  liquor.   It  crystallizes in little
elongated  needles of  a  very sharp  taste.   Fire decom-
poses it rapidly; the product is the hydro-chlorate of am-
monia,  nitrogen,  the  oxide of nitrogen, chlorine, and
water.  According to  Gay-Lussac,  the acid in volume is
to the base as 1 to 2.
   Chlorate of Barytes. Hyper-oxymuriate of Barytes.
V very rare salt crystallizing in prisms, insoluble in alco-
hol.   This substance, according to  Wheeler, is obtained
by dissolving with heat  the chlorate of  potash, and pre-
cipitating the potash by silicated fluoric acid.   The mix-
ture is heated, and all  the potash forms a gelatinous mass
with the silicated fluoric  acid, whilst  the chloric acid, and
a little of the fluoric remain in solution ;  the  liquor is
filtered and saturated by the carbonate of barytes ;  it is a
second time  filtered, in order to  separate the fluoride of
barium, then evaporated and crystallized.
   Chlorate of Copper.  Huper-oxymuriate of Copper,
A  bluish salt, almost  uncrystallizable, deliquescent, red-
dening blue  vegetable colours. It is obtained by combin-
ing directly the deutoxide of copper with chloric acid.
   Chlorate of Lead.   Hyper-oxymuriate of Lead.   A
white, insoluble salt, of  a taste analogous to the salt of
                          14 
158
CHL
 Saturn.   It is obtained in a similar manner to the deuto-
 chlorate of mercury.
   Chlorate  of Lime.  Hyper.oxymuriate of Lime. This
 salt is little known ;  it is sharp, bitter, and deliquescent.
 It is obtained  by direct combination.
   Chlorate  of Potash.  Hyper-oxymuriate of Potash.
 A white salt, in  scales like boracic acid, of a sharp and
 cool taste, fusible at a low temperatuie ; decomposable at
 red heat into oxygen and the chloride of potassium.  The
 chlorate of potash is obtained bypassing chlorine through
 a solution of potash ; as it is little  soluble without heat,
 it is deposited at the bottom of  the vessel under a lamel-
 lar form.  In  this operation one part  of the potash is  de-
 oxidized, and  the  reduced metal uniting  to the chlorine
 forms the chloride of potassium which remains dissolved;
 the oxygen of the potash unites to another portion  of the
 chlorine, and produces chloric acid, which combines with
 the part of the potash not decomposed. {Dulong.)  It is
 formed of 61-23 of chloric acid and 38-77 of potash.
   Chlorate of Silver.  Hyper-oxymuriate of Silver.  It
 is prepared  by pouring  chloric acid  upon the  oxide of
 silver, newly  precipitated and  still moist {Chenevix and
 Vauquelin.)   This salt crystallizes in  prisms, and is, like
 all the chlorates, decomposable.
  Chlorate  of Soda.  Hyper-oxymuriate of Soda.   It
 possesses most of the properties of the chlorate of potash,
 having its taste and form, but it is much more soluble; it
 exhibits  the same appearance when submitted to the ac-
 tion of fire.    It is obtained by saturating the sub-carbo-
 nate of soda with  chloric acid and evaporating it to a
 sirupous  consistence.
  Chlorate of Strontian.  Hyper-oxymuriate of Stron-
tian.  It  is obtained  in the same manner as the chlorate
of lime, of which it possesses most of the properties; it
is easily  distinguished by its power of communicating a
purple colour to flame. 
C  H  L
159
  Chlorate of Zinc. Hyper-oxymuriate of Zinc. Crys-
tallizes in  octoedrons, fuses upon ignited charcoal, pro-
ducing a yellow light.  It is prepared by treating the car-
bonate of zinc with chloric acid.
  Chlorates Oxygenated.   Combinations  of  oxyge-
nated chloric acid with bases. The salts which  result from
this  union have been so little  studied, that  oxygenated
chlorate of potash is almost  the  only one of  which any
thing is known.   This  is without colour, without action
upon litmus, unalterable by the  air,  little soluble in cold,
but much more so in boiling water.    It is decomposed in
the same manner as the chlorate of potash, with a disen-
gagement  of oxygen, and is converted into a chloride.
These salts  were  discovered by Count Stadion.   The
oxygenated chlorate of potash is obtained by mixing one
part of dry pulverized chlorate  of potash, with two parts
of concentrated sulphuric  acid ; this mixture  must be
often shaken, and  the  vessel  containing it exposed to
heat in a sand bath, until the odour  and colour have dis-
appeared.  This mixture is diluted with water, the saline
residue which remains upon the filter is  washed, redis-
solyed in boiling water, and the oxygenated chlorate crys-
tallizes by cooling.
  Chlorine.  (From kloros, green, because it  is of a
green colour.)  Oxygenated muriatic, or oxymuriatic Acid.
A simple  combustible body, not metallic.   It  is  a gas of
a yellowish green, of a taste and odour very disagreeable,
and so strongly  characterized as not to be mistaken for
any other. Its gravity is  2-4216.  It is a supporter of com-
bustion, a wax taper burns in it with a dull reddish flame.
Dry chlorine has never been solidified, or even liquefied,
at the lowest temperature.    If it  is humid, it congeals
below 32°.   The  highest temperature  has produced no
appearance of decomposition ;  like oxygen, it  goes to the
positive pole  of the voltaic pile.  Oxygen  has no action
upon it, unless  the two gases are in contact, when chlo- 
160
C  H  L
rine is in a nascent state, (or evolving from its combina
tion with other substances)  in this case, four different
combinations may take place.  Hydrogen in the dark has
no effect upon it, but if a mixture of the two gases is ex-
posed  to a  diffuse light, they  gradually combine, the
greenish colour of chlorine disappears, and the result  is
a volume of hydro-chloric acid, equal to the two gases.
If instead of exposing the mixture  to diffuse  light, it  is
exposed to strongly luminous rays, there will  be a pow-
erful detonation, and  a very rapid combination will take
place.   The same phenomena may be observed if the
mouth of a  flask filled with this  mixture be exposed  to
the flame of  a taper, or if an ignited substance be intro-
duced into the mixture.
  Hydrogen and  oxygen are not the  only bodies which
combine with  chlorine ;  iodine, nitrogen, sulphur, phos-
phorus, and all the metals possess this  property.   Water
dissolves once and a half its volume of chlorine.   Chlo-
rine is not found in nature except in a  state of combina-
tion.  Its discovery is due to Scheele, a pharmacian,  of
Lincoping, who named it marine dephlogistic acid, it was
afterwards called oxygenated  muriatic acid, or oxymuriatic
acid gas. Berthollet, and Chenevix have paid much atten-
tion to the properties of  this substance ;  the  first made
many important applications of it  to bleaching.   Gay.
Lussac  and  Thenard have  submitted it  to such experi-
ments as to establish a conclusion which throws light upon
the study of its combinations, viz.  that  chlorine can  be
considered in  no  other light than that of a simple sub-
stance.   Davy for a time  opposed this  theory,  but   at
length giving up all his objections adopted it in full.*

  * The French here assume as a fact what is denied by English chemists.  Dr:
Ure says: " So far from the chloridic theory originating in France as has been
more than insinuated, it was only the researches on iodine, so admirably con-
ducted by M. Oay-I.ussac, that by their auxiliary attack of the oxygen hypo-
thesis, eventually opened the minds of its adherents, to the evidence long ago
advanced by Sir.  H. Davy." 
C  H L
161
   Chlorine is thus obtained : six parts of hydro-chloric
(muriatic) acid are poured into a matrass containing one
part of the peroxide of manganese ;  to the neck of the
matrass is fitted a bent tube which is placed under water
in the pneumatic  cistern ; heat being now applied  to the
matrass, chlorine is disengaged ; it is  collected, like most
other gases, in receivers filled with water, which are in-
verted upon perforated shelves  over the cistern.   In this
operation all the hydro-chloric acid decomposes, its hydro-
gen unites with the oxygen of the peroxide of manganese.
and one portion of the liberated chlorine combines with
the manganese, while the other  portion  is disengaged ;
there is then in this process a formation of water,  of the
chloride of manganese, and a disengagement of chlorine.
  Chlorine may be obtained also from a mixture of com-
mon salt (chloride of sodium) and  thp peroxide  of man-
ganese, in the proportion of 44 parts of the former and 1
part of the latter.   Upon this mixture are poured 2 parts
of sulphuric acid, diluted  with its  weight of water ; the
process for obtaining the chlorine is then conducted as in
the case above described.   The phenomena of this ope-
ration are  explained  in several methods; the  following
seems the most  correct :  the sulphuric acid, by its ac-
tion upon the mixture, drives off the chlorine which was
united to the sodium, (forming the salt,) and at  the same
time deoxidizes the  manganese, reducing it to the state
of a protoxide ; the oxygen unites to the sodium, forming
a protoxide of sodium;  at the bottom  of the retort re-
mains a mixture of the proto-sulphates of manganese and
sodium.   {Voy. Traite de Chimie de M.  Thenard.)
  Chlorite.   A mineral of a greenish colour.
   Chlorides. {Chlorures Metalliques.) Combinations of
chlorine with different metals.  The chlorides are com-
pounds so much resembling salts, that they have hitherto
been known  as  such; for example,  the chloride  of so-
                            14* 
162
C  H  L
dium,* (common salt,) which  from remote  antiquity has
borne the name of salt, is not at present, in chemistry, ac
knowledged  as such.   The chlorides are mostly brittle,
solid, and inodorous;  (those  of tin  and  arsenic are li-
quid;) crystallizing regularly; all the chlorides of the
first five sections (See Thenard's divisions of metals) are
undecomposable by fire ;  only one part  of those of the
last section are thus decomposable, as those of gold and
platina. Water dissolves all the chlorides, except those of
silver and the proto-chloride of mercury.  Many chemists
suppose that  as soon as a chloride is dissolved, the water
is  decomposed, forming  a hydro-chlorate ; they found
this theory upon  the great affinity of chlorine for hydro-
gen, and that  of oxygen for the metals ; others think, with
Dulong,  that the solution is effected without any decom-
position, because that  chlorine has  a  great affinity for
the metals, and that  during their  solution, none of the
phenomena are produced which appear during their for-
mation.  What renders it difficult to decide upon either
of these two hypotheses, is the circumstance that in the
hydro-chlorates, the hydrogen and oxygen are exactly in
proportions to form water.  All the metals can unite with
chlorine, and form  chlorides  corresponding to oxides;
from thence the proto-chlorides,  deuto-chlorides, &c.
   The quantity of chlorine, in the chlorides, is to the  oxy-
gen of the oxide of the metal, as 4-388 is to  1 ; thus when
a metal requires 1 of oxygen to become an oxide, it takes
4-888 of chlorine to become a chloride.
   Chlorides Non-Metallic.   Combinations  of chlo-
rine with combustible bodies not metallic.
   Chloride   of  Antimony (Proto.)   {Proto-Chlorure
d'Antimoine.)   A  very caustic compound,  white, deli-
quescent, decomposing water in the same  manner as the

 * The chemical name for common salt was muriate of soda, until the disco-
very of chlorine changed the name to that of chloride of sodium. The sub-
stances described as chlorides will be found in many chemical books treated of
as muriates. 
CHL
163
nitrate of bismuth ; it is very volatile, and may be sepa-
rated by many processes ;  the first consists in making an
intimate mixture of an imony and the  deuto-chloride of
mercury, introducing this mixture into a retort furnished
with an adopter and a balloon, and then moderately heat-
ing the retort; the proto-chloride of antimony being very
volatile, gasifies and condenses in the balloons. It is also
obtained by treating the sulphuret of antimony with hydro-
chloric acid ; the hydrogen of the acid unites to  the sul-
phur of the sulphuret, and the  chlorine  being set  free
combines with  the metal;  the chloride is evaporated to
dryness, and  then sublimed in order to separate  the im-
purities.  M. Robiquet proposes another process, which
produces a very  beautiful chloride ;  it consists in dis-
solving 1 part of antimony in a mixture of 1 part of nitric
acid,  and 4  parts  of hydro-chloric acid ;  the chloride
which results is to be dried in close vessels, and submit-
ted to the process of sublimation.
   Chloride  of  Antimony (Deuto.)   {Deuto-Chlorure
d'Antimoine.)  It is obtained by treating antimony with
an excess  of  hydro-chloro-nitric (nitro-muriatic)  acid;
it  is uncrystallizable, and partly decomposes if submitted
to the action of  fire.   Water acts upon  this deuto-chlo-
ride as upon  the nitrate of bismuth.
   Chloridf. of  Arsenic   {Chlorure  d'Arsenic.)  A
colourless  liquid, very caustic,  poisonous, and volatile ;
it  diffuses in  the  air thick vapours.   It is obtained, like
the proto-chlorides of antimony, by distilling a mixture of
metallic arsenic and  corrosive sublimate.  Arsenic pos-
sessing the property of inflaming when thrown into a flask
of chlorine gas,  this chloride  may  also be  obtained by
passing a current of dry chlorine into a tube containing
fragments of arsenic.   (Thenard.)
   Chloride of  Aluminum.   Deliquescent, colourless,
and styptic ;  it is obtained  by treating  a jelly of alumine
with hydro-chloric acid. 
164
C  H  L
   Chloride of Azote.  See Chloride of Nitrogen.
   Chloride of Barium.   {Chlorure de Barium.)   Very
sharp, poisonous, crystallizes in large  four-sided prisms,
and  liquifies by heat without being decomposed.   The
chloride of barium is obtained  by heating  for  an hour a
mixture  of equal parts  of the chloride  of calcium and
sulphate of barytes ; these two substances in fusing, mu-
tually decompose each other;  the  residue, composed of
the sulphate of lime and the chloride of barium, is diluted
in a  sufficient  quantity of water, filtered  and slowly
evaporated ;  the chloride of barium crystallizes on cool-
ing.   The presence of this chloride is tested by sulphuric
acid, or a soluble sulphate, which instantly forms a white
pulverulent precipuate of sulphate  of barytes, insoluble
in nitric  acid.  The presence of the chlorine which was
united to the barium is also ascertained by a silver  wire,
which forms  a precipitate wholly s >luble in ammonia.
   Chloride of Bismuth.   Colourless,  caustic, of an
unctuous appearance ; it  has  formerly been known  in
commerce under the name of butter of bismuth.   It is,
like the chloride of arsenic, obtained by a mixture of the
metal  with corrosive sublimate ; it distils at a tempera.
ture a little above  red heat.
   Chloride of Calcium.   Bitter,  deliquescent, very
soluble in water, crystallizes, but with difficulty, in six-
sided prisms.  If submitted to the action of fire it loses its
water  of crystallization.   When a solution  of sub-car-
bonate of potash  is poured into the  liquid  chloride  of
calcium, it immediately forms a solid mass,  which the
ancient chemists called miraculum chimicum.   The chlo-
ride  of calcium exists in saltpetre beds, in the waters of
the sea, and  in many springs.  It is easily obtained by
saturating hydro-chloric acid with the carbonate of lime.
In order to obtain it solid, we  must eyaporate the liquid
to a pellicle and crystallize it;  but for common use it  is 
C  H  L
165
 sufficient to evaporate it to dryness, and to preserve it in
 close vessels.
   Chloride of Carbon.  {Chlorure de Carbone.)  Chlo-
 rine  combines  with  carbon  in  two proportions.   The
proto-chloride is liquid, colourless, vaporizes at 165°, is
 not entirely decomposed but at a very high temperature.
 It is insoluble in water, but very soluble in alcohol, ether,
 and the oils ;  most combustible bodies decompose  it, but
 at different temperatures.  Chlorine changes it  into a
 per-chloride.   It is obtained  by  decomposing the deuto-
 chloride by heat.
   The proto-chloride of carbon is formed of 100 parts of
chlorine and 17-39 of carbon, or  in volume of equal parts
of chlorine and the vapour of carbon.  The deuto-chlo-
ride  is  solid,  crystalline,  colourless ; of an  odour like
camphor and  resembling  it a little in appearance.  It
melts at 255°, and vaporizes at 311°.  At a higher tem-
perature it decomposes, forming a proto-chloride.   It is
insoluble in water, ether, the fixed  and volatile oils.
  It is obtained by treating with chlorine the hydro-car-
bonate of chlorine,* and exposing the mixture to the sun.
The  hydro.chloric acid which is  formed,  is  by  water
separated from the deuto-chloride which precipitates ; this
deuto-chloride is formed of 100 of  chlorine and 11-59 of
carbon ; or of two volumes of the  vapour of carbon and
three volumes of chlorine ; neither of the two chlorides
exist in nature.
  Chloride of Cerium (Proto.)   This chloride  which
is little known, is obtained by the action of hydro-chloric
acid  upon the deutoxide of cerium,  at the ordinary tem-
perature ; the  boiling point is sufficient heat for its decom-
 position.
   Chloride of Chrome.   Green, very soluble in wa,
tcr.   It is obtained by treating the hydrated protoxide of

  * This is the olefiant gas, termed by Uraude the hydro-chloride of carbon,
The French term is hydro-earbone de chlorc. 
166                   C H L
chrome with hydro-chloric  acid, as the acid is entirely
without action  upon the dry protoxide ; it may also  be
obtained by  pouring chromic  acid  into  hydro-chloric
acid ; the chloride of chrome and some water are formed.
  Chloride of Cobalt.  Bluish,  deliquescent, astrin-
gent, scarcely crystallizable, very soluble in water.   Its
concentrated solution is blue when warm, but if diluted
with water, it is at all temperatures of a rose colour; this
explains the  phenomena presented by sympathetic ink.
It is prepared in  the same manner as the nitrate of co-
balt.   (See Blue of Thenard, or of Cobalt.)
  Chloride  of Columbium.   Almost unknown; it is
prepared by  treating columbic. acid with hydro-chloric
acid.
  Chloride  of Copper (Proto.)   {Proto-Chlorure de
Cuivre.)  A  white compound, by  contact with the atmos-
phere passing to a green colour more  or  less dark.   In
order to obtain it, equal parts of minutely subdivided cop-
per, and the deutoxide of copper are mixed ; the mixture
is introduced into a  flask containing hydro-chloric acid,
and afterwards carefully evaporated.
  Chloride  of Copper  (Deuto.)   Bluish, of a styptic
taste, crystallizing in needles.   Exposed to the  action of
fire, it disengages water and chlorine, and passes to  the
state of a proto-chloride ; it is deliquescent.   This sub-
stance is usually  prepared  by treating the deutoxide of
copper with hydro-chloric acid ; it oftpm assumes a grass
green colour.
  Chloride  of Gold  (Deuto.)  {Deuto-Chlorure d'Or,)
Muriate of gold.  Of a pale yellow colour, of a metallic
and  disagreeable taste* crystallizing  in  quadrangular
prisms.  According  to M.  Vogel,  when dried in a va-
cuum it becomes green.  Exposed  to heat, it is first
changed to a proto-chloride, and  at  length all  its chlo-
rine is  disengaged.   Tt is  very  soluble  in  water, and
when dissolved is of gold yellow;  it colours all vegeta- 
C  H  L
16'
ble and animal substances a reddish purple.  Almost all
the metals of the first five sections (see Metals, division of)
effect its  decomposition, also hydrogen, ether, the oils,
sulphurous  and phosphorous acids, &c.  Many salts re-
duce the chloride of gold ;  the proto-sulphate of iron pos-
sesses this property in a peculiar degree.
   The proto-chloride of tin reduces it also, precipitating
it of a beautiful purple colour, known under the name of
purple precipitate of cassius.   Alkalies poured into a so-
lution of the chloride of gold precipitate the gold  in the
state of an oxide ;  but  if the solution is acid, it forms a
triple chloride.   If, instead  of potash or soda, ammonia
is  poured  into the solution, it forms a reddish  yellow
flocculent precipitate ;  these flakes well washed  consti-
tute fulminating gold.  The chloride of gold is obtained
by  treating gold  leaf with aqua  regia  (nitro-muriatic
acid); or dissolving gold leaf in a solution of chlorine, and
suitably evaporating the solution.
  Chloride of Gluuinum.  Colourless,  crystallizable,
very soluble, and of a sweet taste.  It  is obtained  by
treating the carbonate of glucina with hydro-chloric acid.
   Chloride  of Iodine.   {Chlorure d'lode.)   A deli-
quescent compound, of which one part is a bright yellow
and the other an orange red.  It  is  decomposed by wa-
ter, which changes it into  hydro-chloric acid and iodic
acid,  if the compound is  yellow ;   but if it is red,  it
is  changed into  the ioduretted iodic acid.  Iodine rea-
dily combines  with chlorine, disengaging  heat.   {Gay-
 Lussac.)
   Chloride of Iridium.   This substance is not known
in a state  of purity ;  it is  always united to the hydro-
chlorate of ammonia, or to the chloride of potassium; in
order  to  combine  it with  the chloride of potassium, it
is necessary to calcine in a platina crucible iridium with
twice its weight of the nitrate of potash.   This product
is   afterward lixiviated, and the residue dissolved in hy- 
168
C  H  I,
 dro-chloric  acid.   This double  chloride presents many
 phenomena which are little known.  When dissolved it
 is at first blue, but if boiled with an  acid, it passes  sue-
 cessively to green, violet,  and red.  (Voyez. le Memoire
 de M. Vauquelin.)
   Chloride  of Iron.   {Chlorure de Fer.)   Greenish,
 styptic,  veiy  soluble, crystallizes easily.   When dried,
 and exposed to the action of  fire in a stone retort, it sub-
 limes in little white spangles.   The  atmosphere  acts
 upon the chloride  of iron much the same as upon the sul-
 phate.  This  chloride can be obtained by putting  iron
 filings into a gun barrel, to one end of which is fitted an
 adopter ; when the gun barrel is heated  to redness, a
 current of dry chlorine is introduced into it, and the chlo-
 ride of iron is formed  in the  adopter.   If the hydro-
 chlorate  of ammonia is mixed with chloride  of iron, the
 result is a yellow volatile  compound, which was formerly
 called martial flowers ;  this is only an intimate mixture of
 the  hydro-chlorate (muriate) of the same base and the
 chloride  of ammonia.
   Chloride of Lead.   {Chlorure de Plomb.)  White,
 sugared, astringent, more soluble by heat than cold ;
 crystallizes in hexahedral satin prisms.  Submitted to the
 action of fire, it melts in a grayish mass, formerly called
 horned lead (plomb come.)  At a red heat it volatilizes in
 thick vapours.   All the soluble  sulphates  decompose it.
 It is sufficient, in order to obtain this chloride, to treat
 litharge (deutoxide of lead) with boiling  hydro-chloric
 acid diluted  with five or six times its weight of  water.
   Chloride of Lime.   (Chlorure de Chaux.)   It is the
 combination of chlorine with the protoxide of calcium.
It is frequently employed in the arts.  It  possesses the
bleaching property of chlorine, and the power of  pre-
serving animal substances from  putrefaction.   It is  pre-
pared by introducing chlorine gas into a kind  of cham-
ber furnished  with little shelves, which are covered  with 
C  H  L
169
pieces  of lime.  Clement  advises to employ in its pre-
paration  the hydro-chloric  acid which is disengaged in
the manufacture  of artificial soda.   It would be neces-
sary to collect it when  it is obtained from the muriate of
soda, by  sulphuric  acid,  and to cause it to pass  over a
chemical  cascade* containing fragments  of the peroxide
of manganese ; the acid  then would be decomposed, and
arrive in the state of chlorine to the place containing the
lime.
   Chloride of Lithium.   Uncrystallizable and  deli-
quescent.  It is obtained  by treating the sub-carbonate of
lithia with hydro-chloric  acid.
   Chloride  of  Magnesium.    Uncrystallizable, bitter,
very soluble.   It is obtained like  the preceding.   This
chloride is usually decomposed by fire.  Gay-Lussac has
published a method for  obtaining it in such a state as not
to be affected by the most intense heat.  This method
consists in introducing  magnesia into a porcelain tube,
and passing  through it a current of dry chlorine ;  all the
oxygen is set free, and  combination immediately takes
place.
   C.iloride of Manganese.   White, styptic, very solu-
ble, deliquescent, crystallizes by spontaneous evaporation.
It is obtained by treating the peroxide of manganese with
an excess of hydro-chloric (muriatic) acid.
   Chloride of Mercury (Proto.)   {Proto-Chlorure de
Mcrcure.)  Calomel.  White,  insipid,  volatile;  it crys-
tallizes in tetrahedral prisms terminated by 4-sided pyra-
mids.   Exposed to  the air for a certain time, it becomes
vellow, and  then  black.  It is wholly insoluble in water

  * Clement  gives the name of cascade chimique to a hollow cylinder, whose
breadth and length vary according to circumstances.  This cylinder is filled
with fragments of some kind of substance, which usually has no action upon
the substance that is to pass over, but which may sometimes affect it, as in the
rase of peroxide  of manganese,  and muriatic acid. These fragments in the
cylinder serve to increase the surface of the liquid or gas which passes through.
                          15 
170                   C H L
 and hydro-chloric acid.   Chlorine dissolves it, changm-
 it into a  deuto-chloride.   If ammonia or  a solution of
 soda or potash is poured upon the proto-chloride of mer-
 cury, it immediately becomes black.   This compound is
 not decomposable by fire; but the simultaneous action of
 water  and charcoal  changes it  into  metallic mercury,
 while hydro-chloric acid, produced by the decomposition
 of water,  is disengaged.   There  are various methods for
 obtaining the  proto-chloride  of mercury; the most  ap-
 proved are the following :
   1st.  Pour a concentrated  solution of the chloride of
 sodium (common salt) into a similar solution of the proto-
 nitrate of mercury ;  a precipitate of the proto-chloride of
 mercury is formed ;  this is sometimes called white preci-
pitate.
  2d.  Form, by saturation, an intimate mixture of 1 part
 of corrosive sublimate slightly moistened with 1  part of
 metallic mercury, and submit this mixture to sublimation.
  3d. Prepare a mixture of the  proto-sulphate of mer-
 cury and the chloride of  sodium,  as for corrosive subli-
 mate ;  then proceed to the sublimation in  a flat-bottomed
matrass ;  this last process is most  approved.
  The proto-chloride obtained by these methods always
 contains  a little  corrosive sublimate,  which is  formed
 during the operation ; it  is divested of .this by washing.
 This compound has  been called  mercure doux, mercure
 sublime doux, panacee mercv.rklle, calomel, calomelas, draco
 mitigatus, &c.
  Chloride  of  Mercury (Deuto.)*    Oxymuriate  of
 Mercury.   Corrosive Sublimate.   White,  crystallizable,
 soluble, of a styptic and disagreeable taste ; treated with
 phosphorus, it  decomposes, forming the chloride of phos-
 phorus, and restoring the mercury.  Charcoal produces
 no effect upon it, even at a high  temperature.   Alcohol
* This is also called the pcr-chloridc. 
C  H L
171
and ether easily dissolve it, at the ordinary temperature.
It dissolves in  three  times its weight of boiling water;
and on cooling, crystallizes in fine satin needles ; ammo-
nia produces in its solution a white precipitate ; potash,
soda, and lime, produce  a brick-coloured precipitate,
which afterwards becomes yellow, if the alkali is in ex-
cess.   Equal  parts  of the hydro-chlorate  (muriate) of
ammonia and  the deuto-chloride  of mercury, sublimed
together in a phial, give a compound which easily sub-
limes ; the residue of this  sublimation is very difficult to
vaporize.
   These two compounds differ from each other but by
their principal  constituents  ; the most volatile,  an ammo-
niacal deuto-chloride, was  known  to the ancients under
'he name of sal alembroth,  salt  of wisdom,  &c.; both of
these compounds are more soluble in water  than  cor-
rosive sublimate.  The most common process  for pre-
paring this deuto-chloride is as  follows :  5 parts of sul-
phuric acid, aided by heat, are  made to act upon 4 parts
of mercury ; heat is continued until the whole is reduced
to 5 parts; then this  acid deuto-sulphate is mixed with 4
parts of pulverized chloride of sodium and  1 part of the
peroxide of manganese ; after a few days, the  mixture is
introduced into little flat-bottomed  matrasses, surrounded
to the neck with sand ; the  mouth is covered with a small
glass capsule.  On being heated, sublimation takes place;
there is a re-action upon the peroxide of manganese and
the chloride of sodium, by  the sulphate of  mercury.   A
heavy white mass is formed upon the sides of the vessel;
this operation continues from 15 to 18 hours;  towards
the close, the bottom^of the sand-bath  must be  brought
to a red heat, in order to give to the sublimation greater
density by commencing its  fusion.
  Chloride  of Molybdenum.   Is obtained in the  same
manner as the  chloride of columbium. 
172
C  H  I
    Chloride  of Nickel.   When  hydrated, it  is grass-
  green ; in a dry state, yellowish green ;  it is very solu-
  ble and sugared.  According to M. Lassaigne, this chlo-
  ride, heated in a retort to a high temperature, sublimes in
  part to the state of an insoluble deutoxide of a  gold-yel-
  low ; and the fixed residue  is a sub-chlorate; it is  pre-
  pared in the same manner as the nitrate of nickel.
    Chloride of Nitrogen.   (Chloride of Azote.) Very
  volatile, vaporizes in the atmosphere, diffusing  a suffo-
  cating odour;  it detonates powerfully at 86°, especially if
  a small piece  of phosphorus is placed in contact with it;
  copper decomposes  it, disengaging  the  nitrogen ;  it is
  preserved in flasks under distilled water.   The prepara-
  tion of this chloride is attended with some danger; it is
 necessary that the nitrogen should be in a nascent state,
 or come in contact with chlorine at the moment when the
 former gas is escaping, otherwise no combination will
 take place ; for this purpose an  ammoniacal  salt is dis-
 solved in water,  and  a  current of chlorine is carefull}
 introduced into the solution.   The chloride of nitrogen,
 being  heavier than water, is  found at the  bottom of  the
 vessel ; but the greatest precaution  is  necessary to pre-
 vent  accident  from  explosion.  It  was  discovered  bv
 Dulong, in 1811 ; this learned chemist was twice wounded
 in studying this singular compound.
   Chloride of  Palladium.  Colour  brownish  ;  crys.
 tallizing with difficulty.  This compound forms with pot-
 ash and soda, triple chlorides which  possess the property
 of crystallizing.  The proto-sulphate of iron instantly re-
 duces the chloride of palladium.   It  is obtained  by dis-
solving palladium in aqua regia.  Tjns chloride has been
particularly investigated by Vauquelin and Wollaston.
  Chloride of Platina. Of an orange yellow, a  styptb-
taste, soluble in water, and affecting iron  like the chin.
ride of gold. 
C  H  L                  173
   Chloride of Phosphorus (Proto.)  {Proto-Chlorure
de Pliosphore.)  Liquid, volatile, colourless, transparent,
heavier  than water,  and very  caustic;  reddening the
cincture  of litmus, but having  no action upon dry litmns
paper.   In contact with  water,  this substance decom-
poses rapidly, and is transformed into hydro-chloric (mu-
riatic) and phosphorous acids.  A process, proposed by
Davy for obtaining this chloride, is to add 1 part of phos-
phorus to 7 of the deuto-chloride.  The proto-chloride of
phosphorus was discovered by Gay-Lussac and Thenard;
according to them, it  is composed of 100 of phosphorus
and 327-6 of chlorine.
   Chloride of Phosphorus (Deuto.)   Solid, very vo-
latile, colours litmus paper red, and crystallizes in trans-
parent prisms.  Oxygen, hydrogen,  and the metals, de-
compose it at red  heat.   It decomposes water very ra-
pidly, changing it into phosphoric and hydro-chloric  (mu-
riatic) acids.   It is obtained by introducing chlorine into
a small matrass containing dry phosphorus, and continu-
ing this operation until all the phosphorus is transformed
into a  white  pulverulent matter.  Some chemists  have
regarded the  chlorides of phosphorus as acids ;  and have
given them the name  of chloro-pJiosphorous for the proto-
chloride,  and chloro-phosphoric  for  the deuto-chloride.
Whatever names be given them, the latter forms with am-
monia  a triple compound,  fixed, insoluble, and undecom-
posable by the alkalies, which may be considered a chloro-
phosphate.   The deuto-chloride of phosphorus was dis-
covered by Davy.
  Chloride  of Potassium.   Colourless, bitter, sharp,  a
little deliquescent,  crystallizes in 4-sided prisms, and de-
crepitates with fire.  It is found in some waters, in vege-
table and animal fluids.   It is obtained directly from hy.
dro-chloric acid and the sub-carbonate of potash.  It was
formerly known under the name offebrifuge salt of Syl-
vius. 
174
C  H  L
   Chloride of Rhodium.   This  compound is hardU
known.  It is easily obtained by treating one of the ox-
ides of rhodium with hydro-chloric acid.
   Chloride of Silver.  (Chlorure d'Argent.)  White,
without taste, fusible at a low heat, it takes a  massive
form in cooling ; it then has a grayish appearance, and is
easily  cut with a  knife.  It  was formerly called horned
silver,  (argent come,) on account of its appearance. The
acids are mostly without action upon this chloride ; boil-
ing  sulphuric acid  decomposes it;  ammonia  entirely
dissolves it.  It is  found, though seldom, in nature.  By
treating metallic silver with  hydro-chloric  acid, or even
by decomposing a salt of silver by the chloride of sodium.
a precipitate is obtained which is the chloride of silver.
   Chloride of Sodium.  (Chlorure de  Sodium.)   Mu-
riate of soda, common salt,  sea salt, mineral salt, &c.
Crystallizes in cubes, transparent.   Its taste is agreeable
to most animals.    Submitted  to the action of fire, it loses
its water of interposition, and at a temperature above red
heat experiences the igneous  fusion without any decom-
position.   Salt is one of the most common substances in
nature.  It is found in a liquid state or in solution, as the
waters  of the sea,  salt lakes,  and springs, and in a solid
state (sel gemme) in mines.
  Mineral salt, (sel gemme,) often called rock  salt.   This
is found in many places, particularly in  Poland, Molda-
via at the foot of mount Krapack, where  a mine of it ex-
tends more  than 150 leagues.  Asia, Africa, and  Ame-
rica contain inexhaustible mines of salt.   Only one mine
(recently  discovered,  near  Vic in  the  department of
Meurthe) is known in France; this is so rich, as  to be
sufficient for the supply of all Europe, for thousands of
years.   Salt is usually found in connection with argillite ;
sometimes a mine extends to a great depth, as in Poland
where  they have already penetrated three  hundred feet
below  the  level  of the sea; it is sometimes found  in 
C  H  L
175
mountains at the most elevated heights, as in the Cordil-
leras, but most commonly it is situated  at the  base of
high mountains.   Mineral salt is transparent, sometimes
blue, yellowish, or violaceous ;  in order to purify it, we
must dissolve and evaporate it.
   Sea salt (sel marin.)  A great part of the salt used in
commerce is obtained from salt water.  Many processes
are employed for its preparation.  When  the waters con-
tain a large proportion of salt, it is extracted by  concen-
trating these waters by fire in large iron caldrons.  During
evaporation, a substance composed of the double sulphate
of lime and  soda, which the manufacturers call schlot, is
precipitated ;  the salt is evaporated almost to dryness ; it
is then drained and dried.  In warm  countries the heat
of the sun is sufficient for the evaporation of  salt water.
For this purpose clay basins are dug near the sea coast,
which are called brine pits ;  the first of these basins is a
vast reservoir which receives the water from a canal pro-
vided with a sluice ;  from this, by means of a slight de-
scent, it is distributed into other smaller  and more shal-
low basins,  which communicate with each other in such
a manner that the  water before it enters them makes a
great circuit.  As soon as the water appears diminished the
basins are replenished.  When about to crystallize, the salt
assumes a reddish  hue, it is then left to deposite the crys-
tals. From time to time the salt  is drawn out and left upon
the banks to dry.  This operation  is usually commenced
in April and completed in September. Other methods are
employed, particularly in evaporating the waters of salt
 springs.*   In all these operations the salt obtained is not
pure, as it  contains chlorides of calcium and magnesia.
of which it maybe divested by crystallization.
   Chloride of  Strontium.   Colourless, sharp and irri-
tating to the taste, soluble in once and half its weight of

   * These operations, upon a very large scale, may be vTitnessed at Salina.
 N. Y. 
t76
C  H  L
 cold water; it crystallizes in long needles, which like the
 wire of strontian, produce with combustible bodies a purple
 flame.   It is obtained in the same manner as the chloride
 of barium.
   Chloride of Sulphur.   Liquid, reddish brown, very
 volatile  at the ordinary temperature, of  a sharp disa-
 greeable smell, strongly reddening the tincture of litmus.
 When in contact  with the atmosphere,  it diffuses thick
 vapours; agitated with  water, a lively  ebullition  takes
 place, caloric is disengaged, a  little  sulphur deposited,
 and a solution of sulphuric, sulphurous and hydro-chloric
 acids is obtained.   The  same phenomena are produced
 with  it by ether and alcohol.  The chloride of sulphur
 poured upon mercury, tarnishes the surface of the metal,
 and forms upon it a grayish  pulverulent  crust of the sul-
 phuret and the chloride of mercury.   The chloride of sul-
 phur  is  obtained by  introducing dry chlorine upon the
 flowers of sulphur placed at  the  bottom  of an eprouvettc.
 the chlorine passing in by means of a bent tube.   This
 operation must proceed slowly, and terminates where all
 the sulphur has disappeared.   The knowledge of this sub-
 stance is due to Thompson.
   Chloride of  Tellurium.  Colourless and uncrystal-
 lizable :  its  solution with water,  deposites a white pre-
 cipitate.   It is obtained by treating  tellurium with aqua
 regia.
   Chloride of Tin  (Proto.) {Proto-chlorure d'Etain.)
 White, very astringent, more soluble at a high than  a low
 temperature, crystallizing in little needles; it takes oxygen
 from many compounds. In contact with the atmosphere, its
 solution is disturbed, and the  deuto-chloride and the  deut-
 oxide of tin are formed.  Molybdic, chromic, and arsenic
 acids  are precipitated in the  state of oxides by the  same
solution.  It precipitates in the metallic state the chlorides
of gold and mercury, and passes  itself to the state of a
deuto-chloride.  The proto-chloride of tin is obtained by 
C  II  L
177
 treating fragments of tin with liquid  hydro-chloric acid:
 hydrogen  is disengaged, and the chlorine unites to  the
 metal.   The solution is  evaporated, and crystallizes in
 cooling.   This compound  is poisonous, and  little em-
 ployed in  the arts.
   Chloride  of Tin   (Deuto.)  Liquid,   transparent
 limpid, volatile, and of an insupportable odour.   Exposed
 to  the atmosphere, it absorbs water and diffuses a thick
 vapour.  In contact with water, it rapidly absorbs it, and
 crystallizes in little white styptic  needles.  It is obtained
 by passing an  excess of chlorine into a solution of the
 proto-chloride,  and concentrating the  liquor by  evapo-
 ration ; or  by amalgamating 1 part  of mercury,  and 3
 parts of tin, pulverizing the amalgam, and mixing it inti-
 mately  with its  weight of corrosive sublimate, afterwards
 introducing this mixture into a retort, furnished with a re-
 ceiver, surrounded with wet cloths. As it is very volatile,
 it needs but a low heat  for  its distillation.   The deuto-
 chloride of tin was discovered by Libavius, from whence
 it received the name of liqueur fumanle de Libavius.  This
 compound  has  been successively studied by  Pelletier,
 Cadet, Proust, and Davy.
   Chloride of Titanium.   Yellowish  white,  and un-
 crystallizable.   It is obtained by calcining the oxide  of
titanium with the  sub-carbonate of potash, and carefully
lixivating the mass in  order to separate the  alkali, and
heating the remainder with  concentrated hydro-chloric
 acid.
  Chloride of Thorim m.   Uncrystallizable;  when
evaporated, it becomes insoluble, and like a white ena-
mel.   It is obtained by dissolving the carbonate of tho-
rinum in hydro-chloric acid.
  Chloride of Tuxgsten.  (Deuto.)  Crystallizes  in
 fine red  needles,  and is produced by burning metallic
 tungsten in chlorine gas.  By water this salt is changed
 into hydro-chloric acid  and oxide of tungsten.   If this 
178
C  II  L
oxide  is  now  heated in chlorine,  the per-chloride  of
tungsten  is generated in the form of white crystalline
scales.   Wohler mentions another  chloride, existing in
transparent red crystals; its  composition,  however, has
not yet been accurately  determined.
   Chloride of Uranium.   Yellowish  green,  deliques
cent, crystallizing  with  difficulty.   It  is  obtained  by
treating the oxide of uranium with hydro-chloric acid.
   Chloride of Yttrium.  Colourless,  deliquescent,  su-
gared, almost  uncrystallizable.   It becomes a jelly by
evaporation.  It is  obtained by treating  the carbonate of
yttria with hydro-chloric acid.
   Chloride of Zinc.  White, styptic, emetic,  deliques-
cent, volatile, of an oily appearance.  It is obtained  by
dissolving the metal in hydro-chloric acid, evaporating it
to dryness, and submitting the residue to sublimation.  It
was formerly called butter of zinc (beurre de zinc.)
   Chloride of Zirconium.    Colourless,  styptic, very
soluble,  crystallizes in little  needles.   It is obtained by
treating the jelly of zirconium with hydro-chloric acid.
   Chlorophylle.    A name  given  by Pelletier and Ca-
venton to the green substance which colours plants.   It
was formerly called the green fecula of plants.   Its  co-
lour is of a deep green, its appearance resinous; when
pure, it has neither odour nor taste ; it  is  undecomposa-
ble by atmospheric air; insoluble in alcohol, ether, and
the oils.*  Sulphuric acid dissolves this substance with-
out decomposing it;  and it may probably be precipitated
without  decomposition,  by saturating the  acid with  an
alkali; the alkalies  exhibit with it similar phenomena.
Chlorine and iodine change  its  colour, the former  to
a green, and the latter  to a  yellow.   It is obtained  by
coagulating the green juice of plants with heat, and puri-
fying the coagulum  with water and alcohol.   (Voyez le
Memoire de MM. Pelletier et Caventon.)
* Dr. Ure says it is soluble in these substances 
C  H  R
179
  (molester axes.  Combinations of  cholesteric acid
with bases.   All the salts which result are coloured either
yellow or orange.  The  cholesterates  of  soda,  potash.
and ammonia, are soluble and deliquescent; all the others
are insoluble.   All the mineral acids except carbonic
acid,  and most of the vegetable acids, decompose the
cholesterates.
  Ciiolesterine.  A name given by  M.  Chevreul to
• lie crystalline substance of the human biliary  calculi.
It exists in brilliant white scales, is insipid, melts at 246°,
and crystallizes on cooling.   Boiling alcohol dissolves it.
Distilled by fire, it gives neither acid nor ammonia; nitric
acid converts it into cholesteric acid.   This substance is
obtained by submitting the biliary calculi to the action of
boiling alcohol;  by filtration and cooling, the cholesterine
separates in beautiful micaceous scales, which are puri-
fied by new solutions.
  Chromates.   Combinations  of  chromic acid with
bases.  The salts which result from this union are all co-
loured.  Most of the chroniates of the  first section, (see
metals, Thenard's sections,) and  those  of the last four,
are decomposed at a high  temperature.   Few  of them
are soluble.   Sulphuric, nitric, and  hydro-chloric acids
appear to decompose them all at the ordinary tempera-
ture.   The  most common chromates are the following:
  Chromate of Ammonia.  Is  obtained by treating, at
the ordinarv temperature, the chromate of lead by a so-
lution of  the sub-carbonate of  ammonia, filtrating the
liquor, and submitting it to evaporation.
  Chromate of Barytes.   Insoluble,  of a pale yellow.
It is  like the preceding, obtained by  decomposing the
chromate  of potash with the nitrate of silver.
  Chromate of Lead.   {Chromate de Plomb.)  Of a
brilliant  yellow  in  the neutral state, and a beautiful
orange in the state of a sub-salt.  It is obtained  by pour-
ino- a solution of the chromate of potash into the neutral 
180                    C  II  R
 acetate of lead, if a  yellow colour is desired;  or it' an
 orange, into the sub-acetate of lead.
   Chromate of Lime.  (Chromate de Chaux.)   Yellow,
 soluble, and crystallizable.  It  is  prepared by  treating
 the  hydrate of lime with the chromate of lead.
   Chromate  of  Mercury.   (Chromate  de Mercure.)
 Red, and insoluble.  It is obtained like the chromate of
 silver.
   Chromate of Potash.   A salt in  rhomboidal prisms,
 of a lemon yellow, a bitter and disagreeable taste.  Sub-
 mitted to a high temperature, a  little  of the acid decom-
 poses ;  it  takes a green  hue on liquefying.  This  sub-
 stance is very soluble in water,  and  little so in  alcohol.
 Potash can combine with an excess of chromic acid ;  and
 the  salt is then, instead of being yellow, of an  intense
 orange colour.  It crystallizes in large rectalinear tables,
 is unalterable by the air, and much less soluble than the
 neutral  chroma.e.  In  order  to  obtain these two chro-
 mates of potash, one part of pulverized ore of chromium,
 and  one part of saltpetre, are put  into a  crucible, and
 strongly heated for two hours in the reverberatory fur-
 nace.   The  nitrate  of potash, (saltpetre,) is   decom-
 posed ;  disengaging the deutoxide of nitrogen, and form-
 ing chromate of potash mixed with the oxide of iron and
 other substances, which made part of  the mineral.  The
 yellow porous substance which remains in  the crucible
 is treated with water, and boiled for  a quarter of an hour ;
 it is  then filtered,  and the  liquor partly evaporated : ni-
 tric  acid is then  added;  this changes  the  liquor to  an
 orange colour, and at the same time  precipitates the silex
 and  alumine  which had been dissolved by  some of the
 alkali.   The  new liquor being  filtered a second time,
 alkali is added until it becomes yellow;  after which it is
 concentrated, and  all  the  nitrate of potash successively
crystallized.  It is concentrated anew, and the chromate
of potash is in turn crystallized.   (Thenard.) 
C  H Y
181
   Chromate of Silver.  {Chromate  d'Argent.)  Of a
 >ieep purple, insoluble.  It is obtained by decomposing
 the chromate of potash by the nitrate of silver.
   Chromate of Soda.  {Chromate de Sonde.)   Yellow,
 very soluble,  crystallizes  easily; it is obtained in  the
 same manner as the chromate of potash, except that the
 nitrate  of soda is employed instead  of  the nitrate of
 potash.
   Chromate  of Strontian.   Resembles  the chromate
 of lime, and is obtained in the same manner.
   Chromium.   {Chrome.)   (From chroma, a  colour.)
 \ solid brittle metal, of a grayish white.  As it is almost
 infusible, it has been obtained only in a porous mass.  Its
 specific gravity is unknown.   Chromium  is  unalterable
 by  the  air, but in a red heat  it absorbs  oxygen.  Its
 cohesion is so great as  not to be overcome by any acid.
 Sulphur, phosphorus, and chlorine, are  the only combus-
 tible non-metallic substances which have been combined
 with chromium.   The discovery of this substance was
made by Vauquelin in analyzing the  chromate of lead
 from  Siberia.   Chromium exists in nature only in  the
 state of a chromate or an oxide.   It is extracted from the
 >xide by calcining  it with charcoal at a high temperature.
 M. Laugier first observed chromium in native iron and in
 the areolithes.
   Chrysocolle.  A name from the  Greek, given to
 borax  on account of its being  used  to solder  gold  and
 other metals.
   Chyle.  An animal liquor, of a milky colour, a sweet-
 ish and saline  taste, heavier than water, greening  the
 infusion of violets;  left to itself, chyle coagulates like
 blood, and is changed into two parts,  a solid and a liquid :
 a little  oil also collects upon  its surface.   The  liquid
 resembles the serum of blood ;  it holds in suspension an
 oily substance, soluble in  alcohol and insoluble in  the
 alkalies.   The solid part,  or curd, is  a mixture of oily
                         16 
182
C  I  N
  matter, fibrine, and serum.   For farther details, see  the
  Memoirs of M. Vauquelin and the labours of Dr. Marcet.
    Chyme.  Is a pulpy matter, of an odour common to
  the animals whose stomachs furnish it.  This substance
  appears to dissolve in acetic acid ;  it does  not contain
  gelatine, but a certain quantity of albumen.  The ana-
  lysis of human  chyme  has not  yet been made.   Dr.
  Marcet has analyzed  that in the  stomach of the turkey.
    Cinchonine.   A vegetable alkaline substance, white,
 translucid,  crystalline, little  soluble in warm water, and
 almost, wholly so  in cold water, of a slightly bitter taste,
 but decidedly bitter when  dissolved in an acid.   Fire
 decomposes one  part, and volatilizes the other.   Cincho-
 nine restores its  blue  colour to litmus which has been
 reddened by an acid, and forms with acids perfectly neu-
 tral combinations.   Mr.  Duncan  of  Edinburgh  first
 obtained a  crystalline substance  from the quinquinas.-
 Gomez described  this  substance under the  name cincho-
 nin; Laubert afterwards undertook to investigate the same
 substance, which he obtained tolerably pure ; but it wa-
 reserved  for  Labillardiere,  Pelletier, and  Caventon  to
 establish its alkaline property and its analogy to morphine.
 The last two chemists undertook the  study of the quin-
 quinas,  and discovered them to possess two salifiable
 organic bases, which they named cinchonine and quinine
 They exist together in all  the plants of the genus quin'
 quina;  the red kind contains equal quantities of  the two
 above-mentioned  bases ; the gray  is mostly composed  of
the cinchonine ; and the yellow of the  quinine
  In order  to obtain cinchonine, the  gray quinquina
reduced to powder is boiled in diluted muriatic add   the
liquor filtered, and again  boiled;  an excess of lime  i«
added ;  it is filtered anew; the deposite is well washed^

  * Cinchona, or Peruvian bark, is obtained from several soeties of  <i,» „.«
Cmchona;  the French include them all under the ^^^^T^ 
C  O A
183
and treated with boiling alcohol, which dissolves all  the
cinchonine ;  it is then evaporated and crystallized.  The
salt is then purified by animal charcoal, and the base is
extracted fron the new salt.
   Cinnabar.   A name formerly given to the Sulphuret
of Mercury.   (See that word.)
   Cistern Pneumatic   (Cuve Pneumatique.)   Pneu-
matic trough.   A  vessel containing water,  used  for  the
purpose of collecting and transferring gases ;  it is some-
times called the hydro-pneumatic cistern. Another, called
the  hydrargiro-pneumatic*  cistern, contains mercury in-
stead of water ; this is used for collecting and transferring
such gases as are soluble in water.
   Citrates.   Combinations of citric acid with salifiable
bases.  All the citrates are  decomposed  by  fire, in  the
same manner as the tartrates.  Among the known citrates,
those of potash, soda, magnesia, strontian,  ammonia, and
iron, are soluble.  The  others are either wholly or almost
insoluble, but dissolve perfectly in an  excess of acid : they
are all products of art. Those which are soluble are obtained
directly ; the others, by double decomposition.  Accord-
ing to Berzelius, in the  citrates, the  oxygen of the oxide
is to the quantity of the acid as 1 to  7-277.  These salts
are  little used, except  the citrate  of lime, from  which
is extracted citric acid.
   Coal.   See Charcoal, Animal, also Wood.
   Coals  Mineral.  Though bitumens, on  account of
their origin,  are  with  more  propriety classed  among
mineral substances, yet in chemical properties, they  are
more closely allied to the products of the vegetable king-
dom.  Like vegetable  substances in general, they burn
in the open  air, and with a degree of brightness  that
surpasses even that of the resins.   By  distillation per se,
Oiey yield a weak acetic acid, an empyreumatic oil, some
t From hydrargyrus, a name for mercury
» 
184
C  O A
ammonia, and  a  considerable quantity of carburetted
hydrogen gas, with occasionally a small proportion of
carbonic acid and sulphuretted  hydrogen.   They are
neither  soluble in water nor in alcohol, and  in the latter
respect they differ from resin.   There can be little doubt
that they have been formed originally by the decomposi-
tion of vegetables.
  The bitumens have been divided into liquid  and solid.
Formerly it was  supposed that  the liquid bitumens  ha<!
been derived, by a sort of natural  distillation, from the
solid; but Mr. Hatchett has rendered  it more probable
that the solid bitumens result from the consolidation of the
fluid ones.
  The bituminous substances are  Naphtha, Petroleum,
Mineral  Tar, Mineral  Pitch, Asphaltum, Jet, Pit-Coal,
Bituminous Wood, Turf,  and  Peat.  To  these  some
writers have added Amber and the Honey-Stone.
  Naphtha is a  pungent,  odoriferous, oily liquid, either
colourless or of a pale brown tint, found upon the borders
of the Caspian sea and in certain springs in Italy.  It is
considerably  lighter  than water,  volatile,  and  highly
inflammable.   When pure, it appears to contain no oxy-
gen, and hence is employed for the preservation of potas-
sium and the other highly oxidable metals.   It consists.
according to Saussure, of
        Carbon     .......87-21
        Hydrogen.......12-79
This would indicate
    6 atoms of carbon   ...   36
    5   "     hydrogen    .   .    5

                                 41          100 H.
  Petroleum has most of the properties of naphtha, but
is less fluM, and darker coloured. In the countries wherf
it abounds, it is employed for burning in lamps.
  100

.   .   .   88
.   .   .   12 
C  0 A
185
   Mineral Tar  appears to be petroleum further inspis-
 sated.  It is more viscid, and of a deeper colour.
   Maltha, or Mineral Pitch,  is a soft inflammable sub-
 stance, heavier than water, and may be  considered as
 derived from the exsiccation of mineral tar.
   Asphaltum is found abundantly on  the  shores of  the
 Dead sea, in Albania, and in the island of Trinidad.  Its
 colour is brown or black  ; it is heavier than water, and
 readily soluble in naphtha.
   Elastic Bitumen, or Mineral  Caoutchouc, is found in
 (lie vicinity of Castleton,  Eng.  and at Southbury in the
 state of Connecticut.   It is fusible and inflammable.
   Mineral Adipocere, is a fatty matter found in the argil-
 laceous iron  ore of Merthyr;  it is fusible at about  160°.
 and  inodorous when cold,  but  of a slight bitumous odour
 when heated, or after fusion.
   The above substances are insoluble in water, and diffi-
cultly soluble in alcohol, with the exception  of naphtha
and petroleum, which are soluble in highly rectified alco-
hol.
   Retinasphaltum  is  a substance which accompanies  the
 Bovey Coal of Devonshire.  It was  first analyzed h}
 Mr.  Hatchett, who found it to  consist of
              55 Resin,
              41 Asphaltum,
               4 Earthy  matter and loss.
   Pit coal.   There are three chemical varieties of this
important substance.  The first, or brown coal, retains
some remains of the vegetables from  which it has origi-
nated.   When heated, it  exhales a  bituminous odour.
and burns with a clear flame.   It is generally of a tough
consistency,  and yields, according to Mr. Hatchett, a por-
tion of unaltered vegetable extract, and resin.
   The second variety, or black  coal, is the ordinary fuel
of Great  Britain.   It exhibits  no traces  of vegetable
origin, and consists principally of bitumen and charcoal,
                          16* 
186
COB
in variable proportions.   When exposed to heat, it swetl>.
softens, and burns with  a bright flame,  leaving a small
quantity of ashes.  Many varieties,  however, abound in
earthy matter, and  these produce copious  cinders, and
burn with a less intense heat.  The  products  of the
destructive distillation of this kind of coal give a residue
of a hard  sonorous charcoal termed coke.  Tlie third va-
riety, glance coal or anthracite, consists almost entirely of
charcoal and earthy matter.
  It usually burns with little flame, and  when submitted
to  distillation  yields no tar, but a sort of carburetted
hydrogen  gas.
  Peat and  Turf consist principally of the remains of
vegetables, having undergone comparatively little change.
They also contain bituminous wood,  branches and trunks
of trees.
  Mellite, or Honey.Stone, is  a rare substance, formed in
the brown coal of Thuringia and in Switzerland.  It is of
a honey  yellow colour,  crystallized  in octoedra,  and
when analyzed by Klaproth, was found to consist of alu-
mina 'combined with a peculiar body which  has been
called  the mellitic acid .*
  Coal Gas.  See  Carburetted Hydrogen.
  Cobalt.   A solid metal, hard, brittle, magnetic, ductile
with heat, closely grained ;  its colour is less shining than
that of tin ;  its density appears to be 8-5384 ;  it fuses at
about 130° of Wedgwood's pyrometer.   It has no action
upon oxygen gas, except at a very elevated temperature,
when it combines with this gas, and produces an oxide.
Among the combustibles it has only  been combined with
sulphur, chlorine, phosphorus, and selenium.   Sulphuric
and hyro-chloric acids dissolve it, and hydrogen is  disen-
gaged  ; it has yet been alloyed with but a small number of
metals.  This metal was  first obtained by Brandt.   It is

       * This article on coal is extracted from Webster's Chemistry. 
COL
18'
found sometimes in connection with ores of iron, copper.
arsenic, &c. and separated by subjecting  to a high tem-
perature the ores which contain it.
  Cochineal.   Was at first supposed to be a vegetable
product, but naturalists soon discovered it to be an insect.
It is brought  from Mexico, where the insect lives upon
different species of the Opuntia.  The colouring extract
from cochineal is called carmine.
  Cohesion.   See Attraction.
  Colcothar.  A name formerly given to the tritoxide
>>f iron.
  Cold.  The privation  of heat.
  Colocyntin.  The  effects of colocynth are thought
by Vauquelin to depend upon this substance.
  Columbates.  Combination  of columbic  acid with
salifiable bases.  These salts, the discovery of which is
due  to  Hatchett, are  scarcely known ;  that  of potash.
which  has been most studied, has a  sharp  disagreeable
taste, crystallizes like  boracic acid ; it is unalterable by
the air, and little soluble in water.   It  is obtained  by
boiling  an excess of columbic acid with  caustic  potash.
The acids powerfully decompose the  columbates, uniting
with their bases, and  precipitating  the  columbic acid.
These substances are of little use.
   Columbium.  A metal  of a dark gray colour, some-
what resembling iron ; when  reduced to powder it be-
comes almost brown.   It  is so hard as to scratch glass.  It
is not  attacked by the acids.  It combines with  oxygen
but in  one single proportion, forming a white oxide, pos-
sessing acid  properties,  and therefore called Columbic
acid.  Columbium is  obtained by heating columbic acid
with charcoal to the highest temperature.  The discovery
of this metal, which is due to Hatchett, was made in ana-
lyzing a compound ore of iron and manganese from Ame-
rica.  The discoverer named it in honour of Christopher
Columbus  (Christophr Colomb.)   It is  sometimes called
Columbium. 
188
C  O M
  Combination.  See Attraction.
  Combustible.  A body which  in its rapid union with
others, causes a disengagement of light and heat.
  Combustion.*   Is the phenomenon  which  appears
when oxygen unites with a combustible  body.  All the
simple substances possess the property of uniting with it;
that is, they are all susceptible of being burnt, and art"
therefore  called combustible bodies.    When a body is
burnt, or combines with oxygen, which is the same thing,
there is always  a disengagement of caloric,  and  some-
times of light, but never of light without caloric.  Before
the time of the distinguished Lavoisier,f  it was supposed
that when a substance was burnt there was a disengage-
ment of an insensible and impalpable principle,  which
the chemists of that  age called phlogiston.   When  this
principle was disengaged from a substance they supposed
it ceased to be combustible, but when it was absorbed it
became combustible.  This theory was at variance with
the well known fact  that bodies increase in weight b\
combustion, but although erroneous, it still reflects greal
honour upon its author Stahh
  Lavoisier's theory of combustion, which followed thai
of Stahl, has in its turn its  object; and at present it is
asserted, that combustion depends upon the combination
of opposite  electricities.  It is a fact that  a piece  of
charcoal placed in a vacuum, and  communicating with
the two poles of the  voltaic pile, soon becomes ignited.
Combustion can then take place without oxygen,  which
i'act must  destroy the theory of Lavoisier, or  at leasi
modify it.   For further details, see the Memoir of MM.
Dulong and Petit.  (Annates de Chimie et de Physique. )

  *  Chlorine and iodine being now regarded as simple bodies analogous to
oxygen, the latter can no longer be termed the only supporter of combustion.
  t Here again the French chemists are at variance with the English as to the
honour of discovery ; the latter asserting that to Sir II. Davy belongs the meril
which the former attribute to Lavoisier.  See Dr. Ure's remarks under the arti-
rlc <'omhvstion. 
COM                   189
  Combustible Substances.   Simple combustible sub-
stances are those  which have  resisted all attempts at
analysis, and which possess  the property of combining
with oxygen,  forming either oxides or acids.   In the
present state of chemical knowledge we admit fifty-two,
including fluorine.   See the article Elements, where these
different bodies are, after  the  order assigned  them by
Thenard, classed according to their greater  or less affi-
nity for oxygen.  The following  is  the classification of
Berzelius, in which the simple bodies are placed in such
a manner, that each one is, in its electricity,  positive with
respect to the one which precedes, and negative to that
which follows it.

  berzelius' classification of combustible
                      BODIES.
. 1.	Oxygen.	No. 21.	Iridium.
2.	Sulphur.	22.	Rhodium.
3.	Azote or Nitrogen	23.	Platina.
4.	Fluorine.	24.	Palladium.
5.	Phosphorus.	25.	Mercury.
6.	Selenium.	26.	Silver.
7.	Arsenic.	27.	Copper.
8.	Molybdenum.	28.	Nickel.
9.	Chromium.	29.	Cobalt.
10.	Tungsten.	30.	Bismuth.
11.	Boron	31.	Tin.
12.	Carbon.	32.	Zirconium.
13.	Antimony.	33.	Lead.
14.	Tellurium.	34.	Cerium.
15.	Tantalum.	35.	Uranium.
16.	Titanium.	36.	Iron.
17.	Silicum.	ST.	Cadmium.
18.	Osmium.	38.	Zinc.
19.	Hydrogen.	39.	Manganese,
20,	Gold,	40.	Aluminum.
 
190
COP
   41.  Yttrium.               45.  Strontium.
   42.  Glucinum.             46.  Barium.
   43.  Magnesium.           47.  Sodium.
   44.  Calcium.              48.  Potassium.
  It will be seen by this list that chlorine and iodine are
omitted, which should have  been placed directly after
oxvgen.   Respecting thorinium and lithium, it is not yei
known where  these  assumed metals should be placed.
This method, which reflects great honour upon its author,
has some inconveniences ;  for example, bismuth relative
to cobalt, and silver  relative to copper, must be as posi-
tive, as  sulphur is relatively to oxygen.   Unfortunatel)
the observations on these points are comparatively few.
  Concentration.  Is an operation by the aid of which
the particles of bodies are brought nearer, by expelling a
superabundant substance.   For example, sulphuric acid
is concentrated by vaporizing a portion of the  water
which  enfeebled it;  a saline  solution is concentrated in
the same manner; vinegar becomes a jelly by concen-
tration.  Thus this process is effected in various ways.
  Copper.  (Cuivre.)   Is of  a fine red colour, ver\
malleable, very fusible, harder than silver, and the most
sonorous of the metals.   When rubbed it throws off a
peculiar and nauseous odour.  When melted its specific
gravity is 7-7880.  It fuses at  27° of  Wedge wood's
pyrometer.  It is not  volatile.  Copper experiences no
alteration from dry atmospheric air, but when in contact
with damp  air its surface  becomes covered with the
oxide,  or the carbonate, according as it is most exposed
to one  or the other of these gases.   When heated  to red-
ness copper oxidizes and  is covered with brown scales.
It can be alloyed with most of the others.  The ancients
gave it the name  of Venus.
   Copper has been known from the most remote anti-
quity,  and next to iron is the  most extensively used.   Ii
serves for a great number of common utensils, to covet 
C  R U
191
buildings, to line vessels, dec.   Combined  with  gold  or
silver, it forms our coin, and  gold and silver ornaments;
alloyed  with  zinc  it  forms  brass; combined with tin
it forms bronze, bell-metal, &c.   It is found in nature in
many different states.   1st, In the native state ; 2d, As a
earbonate; 3d, A sulphuret; 4th,  An  oxide; 5th, A sul-
phate ; 6th, An arseniate; 7tn, A  phosphate.   It is very
(*asy to obtain the metal by fusion  from the native copper.
the oxides, and carbonates ; but it is not so with the sul-
phuret,  which  is  sometimes  for this  purpose  roasted
i wenty times in succession.
   Copper, Yellow.   See Alloys.
   Copperas.  Sulphate of iron.
   Corrosive Sublimate.  The  deuto-chloride of mer-
cury, or oxy-muriate of mercury.
  Coumarin.  A peculiar odoriferous principle, derived
from the Coumarouna odorata or Tonka bean ; it is white.
and  crystallizes  in  prisms—sometimes  in  needles.  If
dissolves readily in ether and alcohol, but is scarcely so-
luble in water.  It was first noticed by Guibourt.
   Cream of Tartar.  See the Acid tartrate of potash.
   Crucible.  (Creuset.)   A vessel of a conical or trian-
gular form, used in chemistry to expose to  the action of
fire, many solid substances.   Crucibles are of stone, por-
celain, iron, silver, platina, &c.  Such  as are manufac-
tured at  Hesse are generally preferred, as they are able
to support a very strong heat without breaking.   These
vessels  are usually  furnished with a  cover of the same
material.
   Crusts.  The bony coverings of crabs,  lobsters, &c.
Hatchett  found  them  to  be composed of a cartilaginous
•substance like coagulated albumen,  carbonate of  lime,
and phosphate oflime.   The great excess of the first dis-
tinguishes them from  bones, while the quantity of the
third distinguishes them  from shells.  Egg  shells and 
192
CRY
 snail shells belong to crusts in composition, but the animal
 matter is in smaller quantity.
   Cryophorus.  The frost-bearer or carrier of cold, in-
 vented by Dr. Wollaston,  to  demonstrate the  relation
 between  evaporation at low temperature, and the pro-
 duction of cold.
   Crystallization.  A name given to the phenomena
 which appear when similar particles of bodies unite on
 account of their cohesive attraction, producing a regular
 solid, called a crystal.  In order that crystallization may be
 effected in a regular manner, much precaution is neces-
 sary.  In  the first place the solution must not be too much
 concentrated, or on cooling, it will  deposite too  great a
 quantity of the substance which  it contains.  This incon-
 venience is obviated by considering the solubility of the
 salts either by heat or cold.  When however a salt is de-
 liquescent, and of course very soluble by cold, it can be
 crystallized only by evaporating the liquor almost to dry-
 ness.  In  order to obtain crystals of much volume, it is
 necessary  to employ a certain quantity of saline matter.
 The solution should be placed where it will stand without
 being in the least agitated ;  and vessels must not be used
 which are liable to be attacked by the salts.   In order to
 procure a  fine crystallization, a certain quantity of sail
 must be dissolved; the solution if not very limpid,  must
 be filtered, then suitably evaporated, and  carefully set
 tside.   In  the space of 24 hours the crystallization takes
 place; the liquor  is decanted by a gentle  inclination of
 the vessel  containing it—this water is called the mother
 water {Veau mere.)  The crystals are then left to drain,
 and should  in many cases be preserved from contact  with
 the air.
  M. Leblanc has  published a process,  by the aid of
 which, he  obtained  very large crystals.   It consists in
dissolving with heat a sufficient quantity of salt; the liquor
crystallizes on cooling,  the  mother Avater  is decanted. 
cue
193
turned into a flat-bottomed vessel, and left to itself at the
ordinary temperature. When isolated crystals are formed,
the most regular are selected and put into other flat-bot-
tomed vessels with the same mother  water; they  are
turned every day, that they may enlarge equally on all
parts of their surface, and the solution is from time to
time changed.  When of a certain size, the crystals are
placed separately in a peculiar kind of vessel, where their
enlargement is terminated.
   Berzelius remarks that crystals, by whatever process
they may  have been obtained,  almost always contain
■t certain quantity of water, which exists either  in a free
-late, or in a state of combination; the former he calls the
water of interposition, and the latter the  water of crystalli.
zation.  There are few salts which contain the  water of
interposition; they are those which decrepitate on heating.
All the deliquescent and  efflorescent  salts possess  the
water of crystallization.   Some  solutions will  not crys-
tallize regularly even at the highest degree of concen-
tration ; but if agitated, they deposite  a  great quantity of
confused crystals.  This phenomenon is owing to the  agi-
fation, which changing the arrangement of the  particles.
puts them into such a situation, that  the surfaces which
ought gradually to  meet in the formation of a crystal.
being thus thrown together, are suddenly forced to unite.
The nitrate of silver furnishes an example of this kind.
bodies which are insoluble in water, may be crystallized
by fusion or sublimation, for  example, sulphur ;  bismuth,
<\sc, being melted in a crucible  and left to cool, form a
crust on the surface, which being penetrated in order to
decant the  liquid part, perfectly formed crystals are  ob
lained.
   Crystals of Venus.  Acetate of copper.
   Cucurbit.   The lower  part  of   an alembic.  (See
this word.)
                           17 
194
C  Y A
   Cupellation.  This  term signifies the  refining  of
metals with lead upon the cupel.   The cupel is a shallow
earthen vessel, somewhat resembling a cup.
   Cyanides.   {Cyanures.)   Prussiates.   Combinations
of cyanogen with combustible bodies ;  in many respects
they  resemble chlorides.  Some  chemists,  with  Gay-
Lussac, think  that the alkaline cyanides neither dissolve
in water nor change their nature ;  others, on the contra-
ry, maintain that the water is decomposed, changing them
to hydro-cyanates.   We  shall, without attempting to de-
cide upon the  comparative merits of these theories, pro-
ceed to a description of the cyanides.
  Cyanide of Iodine.  (Cyanure d'lode.)   Prussiate of
Iodine.   White, in  long and very light needles,  of a
strong odour, very irritating to the eyes.  It has neither
action upon litmus,  nor curcuma paper; chlorine does
not act upon this compound;  the solutions of silver are
not affected by it.   The cyanide  of iodine is obtained by
heating in a phial  two parts of the cyanide of mercury,
and one  part  of iodine;  the  whole should  be perfectly
dry and well mixed.   Action  soon takes  place, and the
result is, the formation of a proto-iode of mercury, and
a very volatile cyanide of iodine, which is  easily  col-
lected by inclining the phial so that the vapour can  pass
into a flask with a  large opening.  This new compound
was recently discovered by M. Serullas.
  Cyanide of Mercury.   (Cyanure de Mercure.) Prus-
siate  of  Mercury.   Colourless,  of  a decided metallic
taste, crystallizes in  quadrangular prisms ; it has no ac-
tion upon litmus.  Submitted to the action of fire, in close
vessels, it decomposes into  cyanogen and metallic mer-
cury ; a  little of the cyanide  sublimes, and a little of the
cyanogen is reduced to its elements.   Heated with one
third of  sulphur, one part of the cyanogen is disengaged,
and the  result is  a sulpho-cyanide  of mercury.   The 
C  Y A
195
cyanide of mercury is more soluble in hot than cold wa-
ter.   Caustic potash dissolves  it, forming a triple  com-
pound susceptible of crystallization.   Most of  the hydra-
cids decompose it; the result  is hydro-cyanic (prussic)
acid, which is  disengaged, and a chloride, an iodide of
mercury, &c.  The cyanide  of mercury in  solution in
water dissolves  a certain  quantity of the oxide of mer-
cury, forming a new compound, which crystallizes  in lit-
tle  clusters.  In order to  prepare the cyanide of mer-
cury, one part of the deutoxide of  mercury is  boiled with
two parts of prussian  blue, and  eight parts  of water:
The mixture is at first blue, and then yellow; the preci-
pitate is filtered  and washed, the waters of the washing
are united, and the  liquor evaporated ; on cooling, it pro-
duces crystals  of the  cyanide.  These crystals are co-
loured by the oxide of iron.  In order to obtain the neu-
tral cyanide, hydro-cyanic  acid must be added to saturate
the excess of mercury; it is then again evaporated,  and
crystallized.   Its composition in weight appears to be  100
of mercury, and 26-086 of cyanogen.
  Cyanide  of  Potassium.   (Cyanure de Potassium.)
Prussiate of potash.   A yellowish crystalline  compound,
alkaline and very soluble in water.   It is obtained by the
action of cyanogen upon  potassium, by the aid of heat,
in a little bell-glass inverted over mercury.  The absorp-
tion is rapid, with an elimination of light and heat.  This
substance is without  use.  It  may also be obtained by
saturating  pure  potash  with  hydro-cyanic acid; analo-
<rous to this cyanide are those of soda, barytes, strontian,
and lime, which are  soluble  and always  alkaline.  All
the  acids, even  carbonic  acid, decompose them.  With
the salts of the last four sections (see metals) they form
cyanides of variable  colours, which are almost all inso-
kible.
   Cyanide of Silver.  {Cyanure d'Argent.)  Prussiate 
190
CYA
of Silver.   White, insoluble, decomposable by fire.  It
is obtained by pouring a solution of the cyanide of potas-
sium into a solution of the nitrate of silver.
  Cyano-Ferrures.  See  Ferro-Cyanates.
  Cyanogen.  (From kuanos blue, and ginomai I produce.
The producer  of blue.)  Prussine. Prussic gas.   Is u
permanent, inflammable gas, of a sharp and lively odour:
its  specific  gravity is greater than that  of  water.  It
reddens litmus, but where the paper is  heated, the blue
ve-appears.  This substance supports a high temperature
without decomposing.  Faraday,  by subjecting it  to a
high degree of cold and pressure, succeeded in bringing
it to a liquid state.  A taper plunged in this  gas  burns
with a purple flame.  Water, sulphuric ether, and essence
of turpentine dissolve four times their volume, and alcohol
twenty times its volume of it.  Cyanogen is obtained by
decomposing by fire the perfectly dry neutral  cyanide of
mercury.   For  this purpose the  cyanide  is introduced
into a  small well  dried retort, to  which is fitted a tube
that passes under  a  bell-glass full of mercury;  being
gently  heated, the cyanogen disengages, and passes into
the bell-glass, while the mercury condenses in the tube.
The science of chemistry owes the knowledge of this sub-
stance to Gay-Lussac, who discovered it in analyzing
what was  then called prussiate of mercury, now  the
cyanide of mercury.  Cyanogen consists of two volumes
of the  vapour  of carbon, and  one volume of nitrogen,
condensed into a single volume.
  Cyano-Sulphuret.  A  new compound, obtained by
heating in a phial a mixture of sulphur, the double cyanide
of potassium, and of iron.  The cyanide of iron decom-
poses ; the result is a sulphuret of iron, and sulphuret of
carbon, and an elimination of nitrogen.   The  other dou-
ble cyanides exhibit similar phenomena.   (See " Traite
 ^ Chimie" de M. Thenard.) 
DEC
197
   Cynopia.  An alkali recently discovered by Ficinus
 of Dresden.  He obtained it in rhombic prisms, from the
 JEthusa cynapium, a species of hemlock.
   Cytesine.  A name proposed by Chevalier and Las-
 saigne to designate a substance which they extracted
 from  the  seeds  of the Cytesus  laburnum.   It absorbs
 powerfully humidity from the  atmosphere,  and has an
 energetic  action  upon the  animal economy.   (See Jour-
 nal of Pharmacy, Vol. IV. p. 340.)


                          D

   Dalhine.  A  white pulverulent matter, very compact:
 it was discovered in the tubercles of the  Dahlia by M.
 Payen.  This substance resembles starch ; it is  however
 little soluble in  cold water ; alcohol precipitates it,  but
 this is not the case with iodine, chlorine, the acetate of
 lead,  hydro-chlorate (muriate) of platina, proto-sulphate
 and trito-sulphate of iron, the nitrate of silver, the proto-
 nitrate of mercury, the sulphate of copper ; these differ-
 ent substances do not precipitate it. Sulphuric acid trans-
 forms  it into sugar.
   Daphnine.  This substance was discovered  by Vau-
 quelin, in the bark of the Daphne.  It is in prismatic fasi-
 cles,  colourless,  transparent, shining, soluble in warm
water, alcohol and ether.   Nitric acid transforms it into
 oxalic  acid; the  acetate  of lead does not precipitate it.
   Daturine.  This substance was discovered by Brande
 in the seeds of the Datura stramonium ; it is insoluble in
water, soluble in  hot alcohol.   The salts which it forms
with acids are dissolved by  water.
   Decantation.    The act of pouring off the  clearer
part of a fluid  by gently inclining the vessel after  the
grosser parts have been suffered to subside.
   Decoction.  The operation  of boiling.  This term is
                         V* 
198
ll  E  L
likewise used to denote the fluid  itself, which has been
made to take up  certain soluble principles by boiling.
Thus we  say a  decoction of the bark or other parts ot
vegetables, &c.
  Decomposition.   A body is said to be decomposed
when by any cause whatever its elements disunite, either
to form new combinations, or to remain isolated.  This
operation  is of  great importance  in  chemistry, as it is
very rare  that one combination  is formed but by the de-
struction of another.  Decomposition differs from analysis
in this respect;  that in the latter the products are care-
fully collected,  and usually an  account is kept of their
quantity.  The analyses, anciently made, were in reality
but decompositions, giving for results, air, earth and water,
which for  a time were  supposed to be the only simple
substances.
  Decrepitation. The crackling noise made by several
salts when  suddenly heated, accompanied by a violent
exfoliation of their particles.
  Deflagration.  This word  is used by electricians
and  chemists to denote  that kind of combustion which
takes place in metallic wires or  leaves, when subjected to
galvanic or electric discharges.
  Deliquescence.  The property  which certain sub-
stances possess of attracting humidity from the atmosphere
and other  surrounding bodies, of becoming saturated,  and
even passing from the solid to  the  fluid state.  Many
salts and  acids  possess this  property ;  such substances
either crystallize with difficulty  or not at all; they are all
soluble in  water, and usually so in alcohol;  in order to
keep them dry they should be preserved in close vessels.
  Delphia.  (Delphine.)   A white powder, very fine,
inodorous, little  soluble in water, dissolving easily in alco-
hoi  and ether.    When thrown upon burning  coals, it
melts, burns without any residue, diffusing a thick white
vapour.   MM.  Lassaigne and  Feneulle discovered  this 
DEN
199
new alkaline base in the seeds of the larkspur {Delphini-
um staphysagria.)  It appears to exist but in the cotyle-
dons, where it is combined with malic acid.  It is obtained
by separating by ether the oily matter of the seeds, boil-
ing them in distilled water, adding a little magnesia and
treating it with boiling alcohol.   The delphia is in time
deposited.
  Demi-Metals,  The ancients thus named the  brittle
metals because they deemed  them less perfect  than the
others.
  Density.   It is easy to perceive  that bodies of the
same volume differ  in weight; this difference is often so
great as to be recognised on lifting substances  with the
hand, but there are means for ascertaining with accuracy
the specific gravity of bodies.
   Among gases, atmospheric air is chosen for a term of
comparison, and a unit of weight.  In order to obtain the
density of any gas, a suitable vessel of a known capacity
must be weighed, at first empty, then filled with dry gas
and again weighed; subtracting the first weight from the
second, the difference gives the  weight of the volume of
gas  contained  in the  vessel.  Observations should be
made relative to the temperature and the pressure under
which the weight is ascertained.  (See Analysis.) Distill-
ed  water is taken as the unit for liquid and solid bodies.
fu order to  ascertain the specific gravity of any liquid,
a vessel is  selected  to  serve for  the common mea-
sure,  this  is   very  exactly weighed,  then filled  with
distilled water  and again weighed ;  it is then  emptied,
carefully dried, and filled with the liquid whose density is
to be ascertained ;  this is weighed, and the weight of the
two bodies under the  same  volume is then found.  But
if the body  is solid,  the following is the most common
process although its specific gravity may in most cases
be obtained  nearly in the same manner.   As it is demon-
stratcd that a body plunged into a liquid, loses  precisely 
200
D  I  G
 the same quantity of its weight as the weight of the vo-
 lume which it displaces, the body is weighed in the air.
 then weighed in the water by means of a thread attached
 to the edge of the balance.  The difference of this weight
 with the first, shows the weight of a volume equal  to its
 own.  If the body weighed was susceptible of imbibing
 water, it would be necessary to  weigh it again  after
 taking it out of the water, and to add to the weight found
 displaced by the liquid, that of the liquid  imbibed.  If the
 body was soluble in water, some other liquid must then
 be used, and  necessary corrections made in the calcula-
 tion.
   Deoxigenation.   Depriving of oxygen.
   Dephlegmation.  Any method by which bodies are
 deprived of water.
   Dephlogisticated.   A term of the old chemists, im-
 plying deprived of phlogiston, or the inflammable princi-
 ple, and nearly synonymous with what is now expressed
 by oxygenated or oxidized.
   Dephlogisticated Air.   The same with oxygen gas.
   Desiccation. Drying up of moisture.
   Destructive  Distillation.   When  organized  sub-
 stances, or their products are exposed to  distillation until
the whole has undergone all that the furnace can effect,
the process is called destructive distillation.
   Detonation.  A sudden combustion or explosion.
   Deuto-Chlorures.  See Chlorides (Deuto.)
   Deut-Oxides.  See  Oxides (Deuto.)
   Deuto-Phosphurets.  See Phosphurets (Deuto.)
   Oeuto-Sulphurets.   See Sulphurets (Deuto.)
   Dew.  The  moisture insensibly  deposited from thf
atmosphere on the surface of the  earth.
   Diamond.  See Carbon.
  Digester.   An  instrument invented to prevent the
loss of heat by evaporation. 
D I  S
201
   Digestion.   The slow action of a solvent upon an\
substance.
   Dilatation.   See Caloric.
   Dippel's Animal Oil.  An oily matter obtained by
the decomposition of horns in a retort.
   Dissolution.  When two bodies being in contact, the
one disappears in the other without affecting its transpa-
rency, this is  a dissolution or a solution.   It is a dissolu-
tion, when the body dissolved has changed its nature and
cannot be obtained in its original state by a careful evapo-
ration ;  it is a solution,  when  by evaporation the body
which was dissolved can be so obtained.   For example,
a solution of sugar in water, and a  dissolution of mercury
in nitric acid.*
   Distillation.   (From distillo, to drop  little by little.)
It is the refining of a volatile substance by means of eva-
poration.   Distillation is simple or complex : it is simple
when a volatile matter is mixed with such as are not vo-
latile, or which volatilize with difficulty; it is  complex
when the distilled matter contains many  volatile princi-
ples, but the one which is to be obtained is the most vola-
tile of all.  There are in distillation two operations of an
opposite  nature, vaporization and condensation.
   The distillatory vessels are either alembics or retorts;
the former consists of an inferior vessel called a cucurbit,
designed to contain  the matter to be examined, nad hav-
ing an upper part fixed to it, called the capital or head.
In this last the vapours are condensed by  the air, or by
the assistance of cold water surrounding the head, and con-
tained in a  vessel called  the refrigeratory.   From the
lower part of the capital proceeds a tube called the nose,
beak, or spout, through which the vapours after conden-
sation are by  a proper figure of the capital made to flow

 * The distinction made by the French chemists between these two words,
seems very proper;  it does  not, however, appear to be noticed by English wr\
rcr*. 
202
E  B U
into a vessel called the receiver, which is usually spherical.
These receivers have different names  according to their
figure, being called balloons, matrasses, &c.  In che-
mistry distillation is mostly performed in retorts.  This
the ancients called  distillation per latus; they called dis-
tillation per ascensum that which is practised in  the com-
mon distilling apparatus;  and per descensum a kind  of
distillation in which the vapours were forced to  descend.
   Ductility.   The  property possessed by  certain me-
tals of being drawn out into very fine threads or wire, or
in very thin  plates, always preserving a certain solidity.
The ancient chemists called those which did not possess
this property half (demi) metals.


                          E.

   Earths.  (Terres.)   This name was formerly given.
and is now applied to oxides which are generally very
abundant in nature, constituting the greatest part of the
globe.   These oxides are found isolated, or in  a mixed
state, scattered over the face of the earth ;  but  they are
more frequently united in a manner to form combinations
in determinate proportions, thus constituting the greater
part of stones.  The earths,  until recently, have been
regarded as metallic  oxides;  it is certain that lime, ba-
rytes, strontian,  &c, are combinations of oxygen with a
metal; but Berzelius has lately ascertained that  silex and
zirconium are non-metallic oxides, and has thus shown that
chemists cannot be positive as to the nature of those that
have not been decomposed.  (See Oxides.)
   Ebullition.   (From ebullio,  to bubble up.)  It is the
the passage of a liquid to the state of vapour. This change
takes place at different temperatures in different bodies,
modified also by the degree of external pressure.  Thus
water,  when pure,  boils at 212°,  at the pressure of  70 
ELE
203
centimetres. But it is only the surface of the water which
offers this  temperature ; the water at the bottom of the
vessel, supporting besides the pressure of the atmosphere
that of the  superior liquid, requires a much higher tempe-
rature to procure ebullition.
   Echini.   Calcareous petrifactions of the echinus, or
sea hedgehog.
   Effervescence.  A species of ebullition produced in
a liquid by the sudden disengagement of a gaseous body,
but which is not the vapour of the liquid from which it has
escaped ; in this case it would simply be boiling.
   Efflorescence.   A property of certain bodies to yield
to  atmospheric air, and  other  gases, part  and even the
whole of the water which they contain.  They are, not-
withstanding, very soluble, for example sulphate of soda
(Glauber's salts.)
  Elaine.   (Oleine.) Is a substance resembling oil;  it
is liquid at the ordinary temperature, has a sweet insipid
taste, is lighter than water, and has an action upon vege-
table colours.   At some degrees below the freezing point
it congeals and crystallizes in needles ; it is volatile with-
out decomposition in a vacuum ; heated in the air, it burns
like the oils ;  100 parts of boiling alcohol of a density of
0-816 dissolves 3-2 of elaine. It saponifies with potash,
and is decomposed into oleic  and margaritic  acids ;  it
furnishes more glycerine than stearine does.  According
to Chevreul, elaine  is composed  of 79-030 of carbon,
11*422 of hydrogen,  and 9-548 of oxygen.  It exists in
the fat of pork, goose, mutton, human fat, &c.   It is ob-
tained by dissolving any one of these kinds of fat in boil-
ing alcohol; on cooling, the  stearine separates ; by eva-
porating the  alcohol, elaine  is obtained in the greatest
purity.
  Electricity.   (Electricite.)  A  property which cer-
tain bodies possess when rubbed, heated, or otherwise ex-
cited, of attracting remote bodies, and frequently emitting 
•iU4
ELE
sparks or streams of light.   The ancients first observed
this property in amber, which they called electrum ; and
hence arose the word electricity.  (The subject of elec
tricity more properly belongs to the department of natu-
ral philosophy than chemistry.)
   Electron.  Greek name of amber;  from whence the
term electricity, this phenomenon being first observed in
amber.
   Elements. {Elemens.) These are simple bodies which
by their  different combinations form all possible com-
pounds.  The ancient chemists  believed that there were
but four elements, earth, fire, air, and water.   We now
acknowledge a much greater number, but our elements
may hereafter meet with  a fate similar to those of the
ancients;  they may be decomposed, and their number
reduced.   Notwithstanding the probability of the conjec-
tures, it would be absurd at present not to regard as sim-
ple those  bodies which resist all attempts of chemists at
decomposition. The elements  are usually divided into
three classes : the first contains oxygen;  the second com-
prehends combustible bodies, non-metallic.  When ranked
according to their affinity for oxygen, they are placed  as
follows:
       Hydrogen.                Sulphur.
       Boron.                   Selenium.
       Carbon.                  Chlorine.
       Phosphorus.               Iodine.
                                 Nitrogen.
   The third class, which is the most numerous, contains
all the metals.  In arranging them according to their affi-
nity for oxygen, they appear as follows :
       Silicum.                  Glucinum.
       Zirconium.                Magnesium.
       Thorinum.                Calcium.
       Aluminum.                Strontium.
       Yttrium.                  Barium. 
F  M  E
205
Lithium.	Cobalt.
Potassium.	Titanium.
Sodium.	Bismuth.
Manganese.	Copper.
Zinc.	Tellurium.
Iron.	Nickel.
Tin.	Lead.
Cadmium.	Mercury.
Arsenic.	Osmium.
Molybdenum.	Silver.
Chromium.	Palladium.
Tungsten.	Rhodium.
Columbium.	Platinum.
Antimony.	Gold.
Uranium.	Iridium.
Cerium.	
   The unknown  radical of fluoric acid, (fluorine)  may
still be regarded as a simple body, also caloric, light, the
electric fluid, and the magnetic fluid.  In addition to the
elements  above  named,  are  two of  recent discovery,
bromine and pluranium.
   Eliquation.   An operation by means of which a more
fusible substance is separated from another which is less
fusible.  It consists  in the  application of a degree of
heat sufficient to fuse the  former, but not the latter.
   Elutriation.   (From  elutrio, to  cleanse.)   This
word is used by chemists to denote the process of wash-
ing,  which carries off" the lighter earthy parts, while the
heavier metallic parts subside to the bottom.
   Emetin.   {Emetine.)   A  salifiable, vegetable  base,
which when pure is white or yellow, pulverulent, fusible
at 122°, changing  colour  in  the air.   It  is very  little
soluble  in water, ether, and the oils, but easily dissolves
in alcohol.  It forms  with  acids  uncrystallizable  salts.
Its solution is precipitated white by nutgalls;  but  it is
not changed by the acetate of lead, or by oxalates and
                          18 
206
ETH
tartrates based upon potash and  soda; it  may thus be
distinguished from quinine, which precipitates with those
bodies.   This substance was discovered by Pelletier,  in
the different species of the ipecacuanha.  It is obtained
by treating the barks of the roots with ether, in order to
separate an oily matter; afterwards treating it with boil-
ing alcohol, which on cooling deposites  the emetin with
a little oily matter, wax,  and gallic acid.   These sub-
stances can be separated  only by treating  the deposite
successively with water, magnesia,  and rectified alcohol.
Emetin is employed in medicine.
  Emetic  Tartar. (Antimonium  tartarizatum.)  It is
obtained by  boiling the  fusible  oxide of antimony with
the super-tartrate of potassa;  the excess of tartaric acid
dissolves the  oxide, and a triple salt is obtained by crys-
tallization.
  Emplatre.  A name given to a mixture  of the mar-
garate and oleate  of lead.   See Margarates, Oleates.
and Saponification.
  Eprouvettes.  These are small bell-glasses, or large
tubes closed at one end, chiefly used for collecting gas
and assaying.
  Equivalents  Chemical.    See  Numbers Propor-
tional.
  Essences.   Several of the volatile or essential oils  are'
called essences by perfumers.
  Ethal.   A peculiar oily substance  whieh Chevreul
discovered in  treating spermaceti  (cetine) with potash.
As its composition is analogous  to  those of  alcohol and
ether, it is named from the  first two syllables eth and al.
It is a solid matter, without colour or odour, insipid, half
transparent, fusible at 122°, and  volatilizing  at a little
higher  temperature.  It  resembles cholesterine  in  not
being acted  upon by alkalies, but differs from it in com-
position, not  giving off cholesteric acid when treated with
nitric acid, 
E  T H
207
  Ether.   The generic name of ether is  given to pro-
ducts which result from the action of acids upon alcohol.
These  products being various, the species is designated
by the  name of the acid used in obtaining it;  as sulphuric
ether, acetic, nitric, &c.  The ethers have been divided
into three sections, according to the elemen'ts which com-
pose them.   The 1st contains those which are formed of
oxygen, hvdrogen, and carbon ;  the 2d contains  those
which  are formed of alcohol and  the acid  employed in
its preparation ;  the 3d section  contains those produced
by the  combination of deuto-carburetted hydrogen with
the acid employed to make them.    In the  first division
are,
Sulphuric
Phosphoric
Arsenic
Fluo-boric
Ethers.
Ethers.
   In the second division are,
           Hydro-chloric (Muriatic)
           Hydriodic
   In the third, which is the most numerous division, are.
           Nitric
           Acetic
           Benzoic i
           Oxalic   /■ Ethers.
           Gallic
           Tartaric
           Citric
   Ether Acetic   (Ether Acelique.)   A  colourless
liquid,  of an agreeable  odour, whose specific gravity is
from 0-866 to 7.   It boils  at 160°, under a pressure of
0-75.   It inflames on the approach of an ignited  body
and  produces acetic acid.   Water dissolves nearly one
seventh of its weight; thus dissolved, potash decomposes
it by taking its acid.   It dissolves many fat substances. 
208
ETH
and is itself dissolved in alcohol.   It is employed m me-
dicine.   It is obtained by distilling to dryness 3 parts of
alcohol, at 104°, and 2  parts of concentrated  sulphuric
acid.   The product is mixed with  one fifth of its weight
of concentrated sulphuric acid and distilled anew, until a
quantity of ether is obtained equal  to that of the  alcohol
employed.
  Ether Arsenic.  See Ether Sulphuric.
  Ether Benzoic.  A colourless liquid, of an oily ap-
pearance, a sharp taste,  having a density  greater than
water.   It is soluble in alcohol  from which it is precipi-
tated  by  water, which  only dissolves  it when hot.   Ii
boils at about  212°.  Potash decomposes it by abstract-
ing its acid.  It is obtained  by heating in a retort a mix-
ture of two parts  of benzoic acid, four parts of alcohol,
and one part  of liquid  concentrated hydro-chloric acid.
The greater part  of the ether remains at the bottom of
the retort. It is then covered with alcohol, water, hydro-
chloric and benzoic acids.  This  ether is  dissolved in
warm water.   On cooling it is deposited in a solid state,
combined with a little benzoic acid; the excess of acid
is abstracted by  a small quantity of alkali.  It is not
used.
  Ether Chromo-Sulphuric.    The  combination  of
sulphuric  acid with  chromic acid,  produces by  contact
with alcohol an ether resembling the sulphuric.
  Ether Citric.  Presents similar properties to the ben-
zoic.   It  is obtained in  nearly the same manner, except
that sulphuric acid is employed instead of hydro-chloric,
in order to facilitate the action of the vegetable acid upon
the alcohol.
  Ether Fluo-Boric.   Differs not from sulphuric ether.
except that fluo-boric acid is employed in its preparation.
See Ether Sulphuric.
  Ether Hydriodic   Liquid, transparent, of an odour
resembling that of other ethers ; its density is 1-9206 at 
ETH                    209
72°.   After a few days it becomes rose-coloured, owing
lo a small quantity of iodine which is set free.  Potash
destroys this tint.   This ether boils at 156° under a pres-
sure of 76 centimetres.  It produces purple vapours when
poured drop by drop upon burning charcoal; but it does
not inflame  on the approach of a burning body.   Potas-
sium,  chlorine, nitric and sulphurous  acids, do not in-
stantly act upon it.   It is obtained  by mixing in volume
2 parts of alcohol  and 1 part of coloured hydriodic acid
having 1 -7 of density, distilling the mixture in a  sand-
bath, and diluting with water the product which is col-
lected in the receiver.  The ether  is precipitated  under
the form of little milky globules, which by their union
form a transparent liquid.  The discovery of its proper-
ties is due to Gay-Lussac.
  Ether Hydro-Chloric    Muriatic  ether.   At the
temperature of 52° and over, it is a colourless gas, of a
very strong odour, taste a little sugared ;  its specific gra-
vity is 2-219, that of  the air  being 1.   Below 52° it is
liquid ;  its density compared to that of water is 0-874 at
41°.  It inflames very easily on the approach of an ig-
nited body,  and burns with a  green flame.   Water dis-
solves  a volume of it equal to its own at 55° ; it dissolves
in alcohol.  Most of the  acids decompose it with heat:
the alkalies  decompose it after a few days.   In order to
obtain this ether, a mixture of equal parts of liquid hydro-
chloric acid at 77° and alcohol at 104° is introduced into
a glass retort; this, being fitted to Woulfe's apparatus, is
placed upon a sand-bath.  In the first flask  is put water
at about 60° ;  the other flasks are left empty.  The dis-
t illing vessels should be long in proportion to their breadth
and surrounded with  ice.   At a gentle  heat  the distilla-
tion  commences ; the gas of ether divests itself of the
superfluous acid and alcohol in the water of the first flask,
and is condensed in the others.  It .is employed in medi-
cine.  It is composed of one volume  of hvdro-chlorb
                         18* 
210
ETH
acid gas and one volume of bi-carburetted  hydrogen.
condensed into one volume.  Its discovery and the study
of its properties are due to M. Thenard.
  Ether Malic.  Differs but little from the  citric  and
benzoic ethers.  (See these words.)
  Ether Nitric.  A liquid of a yellowish white, of a
very strong odour, a sharp burning taste, heavier than
alcohol,  but  less so than  water.  It boils  at  70°,  and
inflames very easily.  Water dissolves a  small  quantity
of it;  but not without decomposing a still greater part,
and  vaporizing more.    If this water is saturated by
potash, there will be a formation of the  hypo-nitrate of
potash.  It is very difficult to preserve this ether without
alteration;  the potash however is not instantly decom-
posed.   This substance is employed  in  medicine ;  it is
obtained by distilling a mixture of equal parts  in weight
of concentrated alcohol and common nitric acid.   The
retort communicates with  five flasks of  Woulfe's  appa-
ratus ;  the first flask is empty, the  four others 'are filled
with salt water.   These  flasks are surrounded with  a
refrigerating mixture.   The  retort must be  carefully
heated, and whenever any signs of ebullition appear, the
fire is taken away and the retort wet with cold water, but
not so  cold as to break it;  when the ebullition ceases, the
operation is terminated.   This ether appears to be com-
posed of alcohol, and hypo-nitric acid, or  rather of nitric
acid, and carburetted hydrogen.
   Ether Oxalic  Differs little from citric acid.   (See
this word.)
   Ether Phosphoric   See Ether Sulphuric.
   Ether  Sulphuric    (Ether Sulfurique.)   It  has
been long  known and  is much  used   particularly in
medicine and in the laboratories  of chemists.  It  is  a
colourless  liquid, of a strong and sweet  odour, of a hot
and sharp taste ; according to  Gay-Lussac, it does not
transmit the electric fluid; it strongly refracts the light. 
ETH
211
is perfectly limpid and very fluid.   Its specific* gravity
is 0-71192 at 75° ; it boils at 95° ;  and the density of its
vapour according to the same chemist is 2-586, atmo-
spheric air being taken for unity.   It solidifies at —46° ;
it inflames with the greatest facility ; can dissolve a small
quantity of sulphur and phosphorus, also  camphor, india
rubber, (caoutchouc,) most fat substances, many salifiable
organic bases, and the  fixed and volatile oils.  It dissolves
a small quantity of alcohol, and mixes with it in  all  pro-
portions.
   In order to obtain  sulphuric  ether, put 6 parts of con-
centrated sulphuric  acid and  5 parts of  alcohol  into a
tubulated glass retort  placed  upon the  sand-bath;  the
alcohol should be first  put into the retort, and the  acid
added gradually;  a glass tube enclosed within  another
tube of tin is fitted to the retort, and to a receiver usually
furnished with a stop-cock and a bent tube for passing off
the gas ;  the  unoccupied space  in the tin  tube is filled
with cold water, which flows out as fast as it heats at an
opening in the upper part of it; the heat must be applied
gradually; in a short time 5 other parts of alcohol musi
be  poured  into  the  retort;  the operation  is continued
until white vapours may  be perceived in  the retort;  as
after this, nothing is  obtained but sulphurous gas, a pecu-
liar liquid called the sweet oil of wine, carburetted hydro-
gen and carbonic acid gases.  The ether, thus  obtained
requires to be rectified ;  for this purpose it is brought in
contact with  -Jj  of  its weight of  caustic potash, which
absorbs  the sulphurous acid and the sweet  oil of wine.
It is decanted, and agitated with water, which unites with
any alcohol  that may be in the ether; and as this ether
has the property of dissolving  a small quantity of  water.

  * Dr. Ure states that it boils at 98°, he referring to the mean annual tempera
mve of England, while the French chemists state its boiling point at 3° less :
this difference is owing to the pressure of the atmosphere in  France being less
ihan in England, on account of the higher t/mperature of the former countrv. 
212
EUD
this latter fluid is abstracted by gently distilling the ether
with the  chloride of calcium.
  It was long believed that sulphuric acid  transformed
alcohol into ether by taking from it a certain quantity of
water ; and the composition of ether seemed entirely to
favour this theory ; at present the decomposition of sul-
phuric acid is admitted, and also that  alcohol consists ot
two parts;  that the one, leaving the water, changes into
ether; (or which is the same thing into  hydrogen and
oxygen in proportion to constitute ether ;) that the hydro-
gen  carries  the sulphuric acid  to the state  of  hypo-
sulphuric acid ; and the oxygen,  by its union with  the
other portion of the  alcohol, forms a peculiar vegetable
matter, which combines  with the hypo-sulphuric  acid.
Ether is composed of 2 volumes of bi-carburetted hydro-
gen  and 1 volume of the vapour of water; if we  add J
volume of the vapour of water, we shall have the compo-
sition of alcohol.  Phosphoric, arsenic, and  fluo-borie
ethers offer the same characters, and are obtained in the
same manner, except that  alcohol  in these  is added  in
small portions by means of a tunnel which passes to the
bottom of the retort.
  Ether Tartaric  Tartaric acid  can  combine with
alcohol through the medium of sulphuric acid; the re-
sult is a sirupous compound, which forms with potash an
abundant precipitate of acid tartrate ; if this is afterwards
treated with alcohol, a peculiar brown and bitter matter
is obtained, soluble in  water and alcohol, and which pre-
cipitates the hydro-chlorate of barytes, but not the hydro-
chlorate  oflime.
  Ethiops of Mercury.   See Sulphuret of Mercury.
  Ethi ops Martial.  See Oxide of Iron (Deuto'.)
  Ethiops Mineral.  See Sulphuret of Mercury.
  Euchlorine.  See Oxide of Chlorine.
  Eudiometer.  An instrument employed in the analysis
of gases, and particularly of atmospheric air.  It consists
of a glass tube, open at one end, and closed at the  other 
F  A T
213
by a stopper of metal with a little wire, surmounted with
a metallic ball, which serves to receive and transmit the
electric spark.  Within the tube is a little spiral wire of
metal which is also terminated by a ball.  This  instru-
ment is varied in many ways.
  Evaporation.   A  chemical operation  usually per-
formed b)  applying heat to  any compound substance in
order to dispel the volatile parts.  It differs from distil-
lation in its  object,  which chiefly consists  in preserving
the more fixed matter, while the volatile substances are
dissipated  and lost, and the vessels are accordingly dif-
ferent ;  evaporation being  commonly  made  in open
shallow  vessels, and distillation in vessels nearly  closed
from the external air.  A current of air, as well as heat.
hastens evaporation.
  Extractive.  (Extractif.)   A principle admitted in
chemistry, but which has  not  yet  been  isolated.  It is
supposed to exist in infusions and decoctions of vegetable
substances, to have the  property of forming  combinations
with many metallic oxides, of being soluble  in water
and alcohol,  of being able to absorb oxygen, and then to
lose its solubility ;  it is thought to contain  nitrogen.
  Extract of Saturn.   See Acetate of Lead (Sub.)


                          F.

  Farina.   Vegetable flour.
  Fat.  (Graisse.)  Is found in most animals  ; its con-
sistence varies from an oily substance to a solid, according
to the  animal,  and the part  which  furnishes  it.  The
colour  and odour  are  variable ; it is usually solid  and
white in the ruminating  animals, soft and of a strong odour
in the carnivorous.   According to Chevreul, fat  is formed
of elaine and stearine in different proportions,  thus pro.
ducing degrees of consistence so  various.  It  contains
also a colouring matter.  Fat substances have  usually r< 
214
F  E R
sweetish  insipid  taste; they are  lighter than  water.
Submitted to the action of fire in distilling vessels,  fat
furnishes a  little water, carbonic,  acetic,  and sebacic
acids,  a great quantity of carburetted hydrogen, and a
little of oily matter.  A small quantity of charcoal which
is easily incinerated remains. Alcohol, sulphur, and phos-
phorus, possess  the property of dissolving  it.   Exposed
to the air it assumes a reddish hue by absorbing a portion
of oxygen.
  Fecula.  See Starch.
  Fecula Green.  See Chlorophylle.
  Fermentation.   A spontaneous   movement  which
takes  place  in  substances;  their  elements  disunite.
combine in other proportions, and give rise to compounds
of which no trace before existed.  The processes offer-
mentation are numerous,  as saccharine, which  affords
sugars ; vinous, spirituous, or alcoholic, where the sugar is
changed into ardent spirit; acid, in which acetic  acid is
the principal result;  putrid or putrifying, which pro-
duces  volatile alkali, and gives a fetid mass.
  Fermentation Acid.  This fermentation takes place
when a spirituous or vmous liquor gives rise to a certain
quantity of acetic  acid.  The production  of this acid
below  50°, proceeds very slowly.  The most  favourable
temperature is  from  59   to 86°.  The liquor  slightly
heated, disengages carbonic acid, and produces a thickish
matter, which is  formed by the deposite of a great quantity
of little filaments, which disturb the transparency of the
liquid.  It appears that the presence  of air  or  oxygen
is  not indispensable  to  the formation  of acid ; but ft
forms in a quantity greater in  proportion  to the  alcohol
contained in the liquor.  It appears then that the  acid re-
sults from a change in the proportions of the constituent
principles of the alcohol.  When the liquor is  exposed to
the air, it may be supposed that the alcohol yielding carbon
and hydrogen to the oxygen of the air, passes to the acid
state, but this fact is  not proved; and when  the liquor 
FER
215
becomes acid without having been in contact with the
air, it is still more difficult to account for the change by a
satisfactory theory.
  Fermentation Alcoholic  Vinous Fermentation. This
takes place when a liquor  containing sugar and  a small
quantity of yest is exposed to a  certain temperature, say
from  68°  to 86°.  The liquor  soon begins to  exhibit
marks of action;  bubbles  of  carbonic acid attracting
around them little  parcels of the yest, form a froth upon
the surface ;  the liquor soon deposites the interposed sub-
stances wffich disturbed it, and becomes clear. The sugar
having disappeared, it seems probable that it has been
transformed into alcohol  and carbonic acid ; it is  thought
that this effect is produced by the yest abstracting from
the sugar, a little oxygen; little can be taken from it, for
but a very small portion is decomposed.  The phenomena
might however be referred to a change of the proportions
constituting sugar, and its  elements combining in other
proportions.  According  to Gay-Lussac,  sugar  may be
transformed  into alcohol, by taking from  the former 1
volume of oxygen gas, and 1 volume- of  the vapour of
carbon, constituting by their union 1 volume of carbbnic
acid gas; thus supposing nothing to be lost, 100  parts of
-;ugar would give 51-34 of alcohol, and 48-66 of carbonic-
acid.   The yest in this  case  would "not have  sensiblv
absorbed oxygen.
   Fermentation  Putrid.  While life remains in  or-
ganized beings, the elements of which they are composed
remain united  according to the laws of  the vital prin-
ciple, which  are often contrary to those of attraction;
but when life is extinct, the principle of attraction governs.
combining the elements in other proportions.  This move-
ment of the particles of bodies is called the putrid fer-
mentation, or putrefaction.   It is more rapid in animals.
than vegetable  substances.  A  damp and stagnant  air
and  warm  temperature  hasten its  progress.   When 
216
f E R
vegetables  deprived of  the  living principle  arc  thus
situated, they change into a black matter called  mould,
furnishing  at the same  time  a  little oil,  acetic  acid,
waters, nitrogen,  carburetted  hydrogen, and  carbonic
acid.  Animal  matter,  under the same circumstances,
besides most of these products, gives ammonia, and many
azotic principles;  as a  little nitric acid, and perhaps  a
little hydro-cyanic acid.   All the gases which are disen-
gaged, carry with them a little animal matter in decom-
position, which gives them an extremely offensive odour.
  Fermentation  Saccharine.  That which*produces
sugar in bodies where it  did not  previously exist.  It is
observed in the germination of many seeds,  and in treat-
ing starch with  sulphuric acid.  It appears in both these
cases, that  there is but one portion of water which com-
bines with starch, (this substance  existing in the seeds of
plants,) and  transforms  it to sugir;  for 100  parts  of
starch furnish 110-14 of sugar ; and it is found  by com-
paring the analysis, that the 10-14 of increase  are only
oxygen and hydrogen  in proportions necessary to form
water.
  Ferro-Cyanates.     (Cyano-Ferrures.)  ' Formerly
called  prussiates.    Combinations  resulting from  the
action  of  hydro-ferro-cyanic  (ferro-prussic) acid  upon
the oxides ; with respect to the composition of these, and
also that of the simple  cyanides, chemists are not agreed
in opinion.
   Ferro-Cyanate of Barium.  (Cyano-Ferrure de Ba-
rium.)   Exists  in small yellowish crystals. It  is like
that of potassium,  obtained by treating the hydrate  of
barytes with prussian blue.
  Ferro-Cyanate of Cobalt.   {Cyano-Ferrure  de Co-
balt.)   Prussiate  of cobalt.    Of a  dark  green when
moist, light green when dry.   It  is obtained by double   "
decomposition; by pouring a  solution of the ferro-cya-
nate of potash into a solution of the nitrate of cobalt. 
F E R
217
  Ferro-Cyanate  of  Copper.   (Cyano-Ferrure  de
Cuivre.)  Prussiate of copper.  Insoluble, of a deep pur-
ple colour.  When heated strongly it eliminates the hy-
dro-cyanate and  carbonate of ammonia  and  nitrogen;
the remainder, which is a  carburet of iron  and  copper,
unite at a low  temperature, in contact with the air.
  Ferro-Cyanate of Iron.  (Cyano-Ferrure de Fer.)
Prussiate of iron.  See Blue Prussian.
  Ferro-Cyanate of Lead.  (Cyano-Ferrure de Plomb.)
Prussiate of lead. Insoluble, white, pulverulent.  When
decomposed by heat, it gives a  compound of  1  atom  of
quadri-carburet of iron,  and 2 atoms  of quadri-carburet
of lead.   It is obtained by pouring a solution of the fer-
ro-cyanate of potassium into the neutral acetate of lead.
  Ferro-Cyanate of Lime.  (Cyano-Ferrure de Chaux.)
Prussiate of lime.  Of a  pale yellow, scarcely crystalli-
zable.    It is obtained like  the ferro-cyanate of barium.
  Ferro-Cyanate of Mercury.   (Cyano-Ferrure de
Mercure.)  Prussiate of mercury.   An insoluble com-
pound, obtained by pouring a solution of the ferro-cya-
nate of potassium  into a solution of corrosive sublimate.
By contact with the air, it decomposes into a  cyanide
and prussian blue.
  Ferro-Cyanate of Potassium.   {Cyano-Ferrure de
Potassium.)  Prussiate of potash.  Of a fine orange co-
lour, transparent, inodorous, of a saltish and slightly bit-
ter  taste.  Submitted to  a heat  of 140°,  it fuses in its
water of interposition, and becomes white ; by elevating
the temperature to red heat, it  undergoes  the  igneous
fusion without  any decomposition; at length by raising
heat sufficiently intense to affect the glass  retort contain-
ing the substance, a  little nitrogen is eliminated, and the
remaining mass is composed of the quadri-carburet  of
iron, and the cyanide of  potassium ;  but the decomposi-
tion is  never total.   Hydro-chloric acid takes the potash
from the ferro-cyanate, and liberates the hydro-ferro-cya-
                          19 
218
F  I  B
 nic acid.  Cold  sulphuric acid dissolves this compound .
 decomposing it  at an  elevated temperature;  in this
 change there is a formation of sulphates of iron, potash,
 and ammonia, and an elimination of sulphurous and car-
 bonic  acids and  nitrogen.  Hot nitric acid also causes a
 disunion of the constituent principles of this ferro-cya-
 nate, the result  being the nitrates of potash  and iron.
 The solution of the ferro-cyanate of potassium is preci-
 pitated neither by the alkalies nor alkaline salts.   With
 the salts of the last four sections* it forms precipitates ol
 various colours;  the most remarkable are the following :
 with the protoxide of iron the precipitate is white, and
 with the deutoxide it is of a very intense bluish green ;
 with the protoxide of copper  it is white,  and with the
 deutoxide of  a  reddish  yellow.  The  ferro-cyanate  of
 potash, formerly called prussian alkali and prussiate  of
 potash, is in  laboratories  made with prussian  blue.   For
 this purpose, prussian  blue of commerce is treated with
 sulphuric acid diluted with water, in order to carry off
 the alumine; the residue is washed to  divest it of the
 little  acid which it might  retain;  this  residue is then
 added by small portions into a  solution of boiling potash,
 until the liquor has lost its brownish hue ; it is then fil-
tered, evaporated, and  crystallized ;  then redissolved and
 crystallized  anew, to purify it.   It is prepared on a large
 scale for use in the  arts, by calcining dried blood or other
 animal substances,  with the sub-carbonate of potash, the
 same as for prussian blue.
   Ferro-Cyanic Acid.   See Acid Hydro-Ferro-Cyanic.
 Formerly called  ferro-prussic acid.
   Ferro-Prussic Acid.   See Acid Chyazic.
   Fibrin.  {Fibrine.)  A substance  very abundant  in
 the animal  kingdom; it constitutes the greater part of
 muscular flesh ;  it  is also found in a minutely subdivided
* See metals, Thenard's Sections. 
FLA
219
 state, in many  animal liquids, such as chyle, blood, &c.
It is a solid matter, without taste or odour, of a yellowish
colour, and like gelatine, semi-transparent, susceptible of
absorbing about four  fifths of its weight of water, and of
then becoming  white, flexible, and elastic.  Alcohol and
ether soften, and in time render it  pulpy.   The acids act
upon it in various ways, sometimes combining with it as
the  hydro-chloric and  weak  sulphuric  acids;  at other
times they decompose it, as the concentrated sulphuric
acid and nitrous acids.  Fibrin dissolves  in the alkalies
when cold, and is decomposed by potash and soda, with
heat.  It may be  obtained by beating with a bundle  of
twigs blood recently  taken from the veins.   Fibrin soon
attaches itself to each stem, under the form of long red-
dish filaments, which become colourless by washing them
with  cold water ;  it should then be dried in the open air.
According to Gay-Lussac and Thenard, it is composed of
               Carbon,  -   -   50-360
               Nitrogen,    -   19-934
               Oxygen,  -   -   19-685
               Hydrogen    -    7-021
   Filter.  {Filtre or Filtrum.) An instrument for strain-
mg,  in order  to separate from a liquid any body which
 may  be held in suspension.   Paper called cap-paper, is  "
most commonly used; but when the substance to be filter-
ed is of a nature to act upon  paper,  or would easily ob-
struct its pores, other  substances are used :  as wool, tow,
sand, charcoal,  pounded glass, and even straw, &c.
  Filtration.   {Filtrdtio ; from  filtrum, a  strainer.)
 \\\ operation, by means of which, a fluid is mechanically
separated from consistent particles, merely mixed with it.
It does not differ from straining.
   Fire.   (Feu, Latin Ignis.)   See Caloric.
   Fixed Air.   See Carbonic Acid Gas.
   Flame.  A gaseous matter, whose temperature is suf-
ficiently elevated to appear luminous.  See Caloric. 
220
FLU
  Flesh.   (Chair.)   The  muscles of animals.  The}
consist chiefly of fibrin, with albumen, gelatine, extractive
matter, phosphate of soda, phosphate of ammonia, phos-
phate and carbonate of lime, and sulphate of potash.
  Flour.   The powder  of the gramineous seeds.   Its
use as food is well known.
  Flowers.  A general term used by the  ancient che-
mists to denote  all such bodies as have received a pulve-
rulent form by sublimation.
  Flowers of Antimony.  The sublimated protoxide of
antimony.
  Flowers of Arsenic  The deutoxide of arsenic.
  Flowers of Benzoin.  Benzoic acid.
  Flowers Martial.  Ancient name for the sublimated
chloride of iron.
  Flowers of Sulphur.   Sublimated sulphur.
  Flowers  of  Zinc.   Ancient name for the oxide of
zinc.
  Fluates.   By this name are  known the combinations
of fluoric acids  with salifiable bases, combinations which
many chemists regard as fluorides ;  but as fluoric acid
acts, usually like the oxides,  especially in its union with
boracic acid, silex, and by its  action on  alcohol which
gives rise to an ether similar to that obtained with sulphu-
ric acid, we have thought proper to adopt ihis hypothesis,
until the decomposition of this acid shall decide the ques-
tion.  If these  supposed  salts, the fluates, are submitted
to the action of caloric, they are partly or wholly decom-
posed if they contain water;  if they  contain none, de-
composition does not take place.
  Water dissolves only those of potash, soda, and silver,
except the others are acid fluates.   Lime water disturbs
all the solutions of the fluates ; strong sulphuric acid sets
free their fluoric acid.  Many other oxacids and all the
hydracids, decompose it equally, but always through the
medium of water.  Boracic acid combines with fluoric 
I  L U
22 J
acid and possesses the property of decomposing the dry
fluates at a red heat.  Silex combines also with fluoric
acid, singularly  promoting  the decomposition  of the
fluates.  In these salts  the quantity  of oxygen of the
oxide is to the quantity of the acid as 1 to 1 -373.  Those
which are  soluble are  obtained by  a direct process, the
others by  double  decompositions.  W7e shall  proceed
to describe some of the most important fluates.
   Fluate of Ammonia. (Fluate d'Ammonique.) By pour-
ing weak fluoric  acid upon  diluted  ammonia, and  care-
fully evaporating the liquor, a salt is obtained of a very
pungent taste, crystallizing with  difficulty,  and readily
decomposing  by  heat, which drives off a portion of the
ammonia, and afterwards volatilizes it in the state of an
acid fluate.  It acts in most respects with different bodies
in the same manner as the other fluates.
   Fluate  of  Lime.  (Fluate de Chaux.) Fluor spar.  Is
found abundantly in nature, often in cubic crystals with
variable  colours.   It is phosphorescent  with heat,  fuses
at an elevated temperature.   It is employed  in the pre-
parations of fluoric acid.   It is often called  Derbyshire
spar, as it is in the mines of Derbyshire, England, that it
is chiefly found.
   Fluate of Potash.   (Fluate de Potasse.)   Deliques-
cent, very fusible, not decomposable by heat, even with
the aid of  water, decomposable by sulphuric acid at the
ordinary temperature ; it is obtained by  a direct process.
   Fluate Acid of Silex.  (Fluate Acide de Silice.) Si-
licated  Fluoric  Acid.   A  colourless gas  of  a strong
odour and caustic taste, extinguishing combustion, having
a specific gravity of 3-5735.   It is not decomposed by
heat, but water acts upon it ;  one  part containing much
silex is precipitated in the  state of jelly, the other part
very acid dissolves.   Boracic acid  precipitates the  silex,
and combines with the fluoric acid ; the  alkalies also de.
compose it.   The acid fluate of silex is formed
                           in* 
222
FLU
                  Silex  -   -   61-4
                  Fluoric acid  38*6
It is obtained by treating with sulphuric acid a mixture of
the fluate of lime and sand.
  Fluate of Silver.   (Fluate d'Argent.)  Is obtained
by a direct process.  It is very soluble, deliquescent, and
possesses many of the properties of the nitrate of silver ;
it fuses easily, and colours the skin black.   Muriatic acid
solidifies its solution.
  Fluate of Soda.   (Fluate de Soude.)  It is not deli-
quescent like that of potash, it is less soluble, less fusible.
decrepitates before melting.   It is obtained by saturating
with soda a solution of the acid fluate of  silex, filtering
and  evaporating the  liquor,   See, for further details re-
specting the fluates, the works of Gay-Lussac and The-
nard, ("Recherches Physico Chemiques," tome ii.,) and the
Memoirs of Berzelius, (" Ann de Chymie et de Physique.")
  Fluids Imponderable.  By this name  are known ca-
loric and light,  the  electric and  magnetic fluids,  they
being without any known weight; although these  fluids
give rise to many phenomena in chemical combinations.
yet they are all,  except caloric, considered as properly
included under the science of natural philosophy.  For
information upon caloric, see that word.
  Fluo-Borates.  At present the  only  combination
known of the fluo-boric (boracic) gas is with ammoniacal
gas, 1 volume  of the  former can combine with 1, 2, 3
volumes of the second, giving rise to three salts, only the
first of which is solid ;  the others which are liquid, solidify
by heat, losing a  portion of  the  ammoniacal gas which
they contain.
  Fluoric Acid.  See Acid Fluoric.
  Fluoride of Calcium.  Insoluble in water and hydro-
fluoric acid, and but slightly  dissolved  by hydro-chloric
(muriatic) acid.   It may be formed by  digesting newlv 
F  R E
223
precipitated carbonate of lime in an excess of hydro-
fluoric acid.
  Fluoride of Manganese.   A yellow gas changing to
a deep red colour when united with atmospheric  air;
acting rapidly  upon glass, depositing upon it a brown
substance, and  forming a fluo-silicic acid gas.  This gac
has been recently discovered by Drohler and Dumas ; it-
farther properties are not known.
  Fluorine. {Fluor.)  The imaginary radical of fluoric
acid,  called also by the French phtore.
  Flux.  A  general term made use of to denote  any
substance or mixture added to  assist the fusion of metals.
  Fluxion.  See Fusion.
  Formiates.   Compounds of formic acid with the  sali-
fiable bases; they  are little known,  are all soluble in
water, crystallizable, and resemble the acetates in many
of their properties.
  Freezing Mixtures.   These  depend for their effect
upon the disappearance of sensible caloric,  when bodies
become liquid, especially without the aid of heat.   The
most  usual method for producing artificial cold is to mix
equal quantities of snow and salt; the latter having a great
affinity for water causes the snow to melt.   The salt is
then  dissolved,  and the thermometer marks  thirty-two
degrees below the freezing point.   Other mixtures  may
be prepared  which will  reduce the  thermometer  still
lower.  The salts employed should be recently crystal-
lized  and reduced to powder,  and previous to their em-
ployment, their temperature should be reduced by cooling.
The  following  are the results of Mr. Walker's  experi-
ments upon this subject. 
221                    F U L
MIXTURES.	thermometer SINKS.
Parts. Muriate of Ammonia, - - 5 Nitre, - - - 5 Water, - - 16	From 50° to 10°
Nitrate of Ammonia, - - 1 Water, - - - 1	From 50° to 4o
Sulphate of Soda, - - - 5 Sulphuric and Diluted, - 4	From 50° to 39
Muriate of Lime, - - - 3 Snow, ------ 2	From 32o to —50°
Diluted Sulphuric Acid, 1 Diluted Nitric Acid, - - 1	From —10° to —56o
Snow or Ice, pounded, - 12 Common Salt, - - - - 5 Nitrate of Ammonia, - - 5	From —18° to —25°
Muriate of Lime, - - - 3 Snow, ------ 1	From —40o to —73°
Diluted Sulphuric Acid, - 10 Snow,......8	From —68o to —94°
Phosphate of Soda, - - 9 Nitrate of Ammonia, - - 6 Diluted Nitrous Acid, - 4	From 50a to —21°
  Fuliginous.   (From fuligo,  soot.)  Vapours which
possess the property of smoke, or soot.
  Fulmination.   Detonation.  A  quick and  lively ex-
plosion of bodies.
  Fulminating Substances.   (Fulminates.)   Such  as
are remarkable  for a  property  of detonating by  slighl
friction or exposure to a high temperature.  Fulminating
silver, which is better known than  any of the substances
of this  class, is soluble in 36 parts of boiling water.  Pot-
ash and  soda poured into  this  solution precipitate part
of the soda and form a double salt.  Most of the metals
which  are introduced  into this solution take the  place of
the silver, and form other  fulminate-'. Avhose  properties 
FUS
225
are not well known.  The fulminate of silver, usuallv
called fulminating powder of silver, is obtained by pre-
cipitating with alcohol a  solution of silver in nitric acid ;
most  of the others may be obtained by an analogous pro-
cess.   According to Gay-Lussac and Liebig, the fulmi-
nate  of silver is composed of 77-528 oxide   of  silver.
22-472  fulminic acid.
   Fumigation.   (From  fumus, smoke.)   The applica-
tion of fumes to  destroy effluvia or contagious miasmata.
   Fungin.   (Fungine.)  A name  given by Braconnot to
the fibre of mushrooms, which differs from woody fibre in
containing nitrogen.  It  is obtained by successively boil-
ing mushrooms  in  an alkaline water.  It is white, soft,
tasteless, insoluble in most substances, dissolves by heat
in muriatic acid, is decomposed by nitric acid, giving
among other  products oxalic acid  and  two peculiar oily
substances.
  Furnaces.  Instruments  used in  exposing  bodies to
the action of caloric; their forms  are various, according
to the uses for which they are designed.   The  following
are some of the  most common :
   1st. The evaporating furnace;  it is employed  to re-
duce  substances  into vapour by means of heat in order
to separate the  more fixed  principles from  the more
volatile.
  2d. The reverberatory  furnace, which name it has re-
ceived from its construction ; the flame being  prevented
from rising, it is appropriated to distillation.
  3d. The forge furnace, in which the current of air  is
determined by bellows.
   Fusion.   (From fundo, to  pour out.)   A process by
which bodies are made  to  pass from a solid  to a fluid
state by the application of heat.   Salts are liable to two
kinds of fusion, the one owing to water contained  in the
salt, this is called  the  aqueous fusion; the other,  which
arises from heat alone, is called the igneous fusion, 
226                   G A  L
                         G

  Galbanum.  The juice of the Bubon galbanum.
  Galena.   (Galene.)  Mineralogical name for the sul-
phuret of lead.
  Galls.   Protuberances produced by the puncture of
an insect on plants and trees of different kinds; some of
them are hard and  called nutgalls, others are soft and
spongy, and called berry-galls, or apple-galls. (See Gallic
Acid.)
  Gallatf.s.  Salts resulting  from the combination of
gallic acid with bases ; they are little  known; those of
potash, soda,  and those of organic bases, are soluble and
without colour.   The  gallate (per) of iron is blue ;  all
the gallates are decomposable by  fire.  All the strong
acids seize upon their  bases ; the gallate of iron is decom-
posed  by  oxalic  acid.   The  neutral  gallates of cin-
chonine and quinine are insoluble, except in an excess
of acid.
  Galley.   (GaUre.)  A  long reverberatory furnace,
around the interior of which are arranged rows of vessels,
as retorts, crucibles, &c. to be heated at the same time.
Some galleys consist of a long  furnace covered with an
arch, with a chimney at one end, and at the other  a door
for the introduction  of the fuel.  On account  of the ap-
pearances of the furnaces, and the  lateral openings, the\
are supposed to have some resemblance to  a row-galley ;
ibis has given rise to their name.
  Galvanism.  A  professor of anatomy in the univer-
sity of Bologna, named Calvani,  was  one day making
electrical  experiments in his  laboratory;  near the ma-
chine were some frogs that had recently been flayed, the
limbs of which became  convulsed every  time a spark
was drawn from the  apparatus.  Galvani, surprised al
this phenomenon, made  it a subject of investigation, and 
GAS
22-;
 discovered that metals applied in a certain manner to the
 nerves and muscles of these animals, occasioned power-
 ful and  sudden contractions.  He gave the name of ani-
 inal electricity to this order of new phenomena, from the
 analogy that  he considered as existing between these
 effects and those produced by electricity.  The name of
 animal electricity  has  been superseded by that of gal-
 vanism,  in honour of the discoverer.
   Gangue. .  The stones  and earths which  surround
 mines, and in  which the ores are imbedded.
   Gas.   (From  Geist,   German,  signifying  spirit.)
 Gaz.   The gases are aeriform, very elastic and compres-
 sible,  of a  specific gravity varying  according  to  their
 nature and the presence of the atmosphere; some are
 absorbed with  great facility by charcoal and other porous
 bodies, others are absorbed with  difficulty.  The num-
 ber of gases is estimated at 26 ;  it is probable that future
 discoveries will increase this number.  The gases vary
 in their  appearances and  qualities;  for example, some
 may be liquefied by a high pressure or low temperature ;
 some are coloured, others diffuse white fumes ; some ex-
 tinguish combustion, others restore combustion  after it
 has been extinguished ;  some are acid, others are alka-
 line ; some are deleterious, producing a strong odour:
 many dissolve in water.
   1.  The coloured gases  are nitrous acid, chlorine, the
 protoxide and  deutoxide of chlorine.   The first  is red,
 the rest yellowish green, or yellowish.
   2. Gases producing white vapours in the air, muriatic,
 fluoboric, fluosilicic, and hydriodic acids.
   3. Gases inflammable in air by contact of the lighted
 taper.   Hydrogen,  sub-carburetted,   carburetted,  sub-
 phosphuretted, phosphuretted, sulphuretted, arsenuretted,
tclluretted, and potassuretted hydrogen, carbonous oxide
iiass and prussine or cyanogen. 
228                    GAS
   4. Gases  which rekindle the expiring taper: oxygen.
 protoxide of azote, nitrous acid, and the oxides of chlo-
 rine.
   5. Acid gases which redden litmus.   Nitrous, sulphu-
 rous, muriatic, fluoboric, hydriodic, fluosilicic, chloro-
 carbonous, and carbonic acids, the oxides of chlorine,
 sulphuretted hydrogen,  telluretted hydrogen, and cya-
 nogen.
   6. Gases destitute of smell, or possessing but a feeble
 one : oxygen, azote, hydrogen, sub-carburetted and car-
 buretted hydrogen, carbonic acid, protoxide of azote.
   7. The smell of all the others is insupportable, and
 frequently characteristic.
   8. Gases very soluble  in water; namely  of which wa-
 ter dissolves more than 30 times its volume at ordinary
 pressure and temperature.  Fluoric, muriatic,  fluosilicic,
 nitrous, and sulphurous acids, and ammonia.
   9. Gases soluble in  alkaline  solutions.   Acids nitrous,
 sulphurous,   muriatic,  fluoboric,  hydriodic,  fluosilicic,
 chlorine, carbonic,  chloro-carbonous, and the two oxides
 of chlorine, sulphuretted hydrogen, telluretted hydrogen,
 and ammonia.
   10. Alkaline gases.   Ammonia and  potassuretted hy-
 drogen.
  As it is  not possible  to give a general  description of
the various gases  which would in any degree illustrate
their peculiar qualities, each gas will be described under
its appropriate head.
  Gas  Hydrogen  See Hydrogen.
  Gas  Olefiant.  See Bicarburetted Hydrogen.
  Gas  Inflammable.    See Hydrogen.
  Gas  Nitrous.   See Oxide of Nitrogen (Deuto.)
  Gas  Dephlogisticated.  See Oxygen.
  Gas of Marshes.  (Gaz des  Morals.)   See Carburet-
led  Hydrogen. 
G L A
229
  Gastric Juice.  A peculiar fluid secreted by the sto-
mach to assist in the digestive process.  Its taste is saline,
and vegetable colours are not  affected by it.
  Gelatine.   Gelly, or jelly.   An animal substance
soluble in water, but not in alcohol, capable of assuming
a well known elastic or tremulous consistence by cooling,
when the water is not too abundant, and liquefiable again
by increasing the temperature.  This last property parti-
cularly  distinguishes  it from  albumen, which acquires
consistence by heat.  Gelatine, or jelly, is the principal
ingredient of skin and all the  membranous parts of ani-
mals.  It may be obtained by  boiling in water, under the
forms of glue, size, isinglass, and transparent gelly.
  Gentianine.  A name proposed by Henry and Cavern
ton, in order to designate  a crystallizable substance of a
bitter taste,  analogous to gentian, having no action upon
either litmus or curcuma paper.  It is very soluble in alco-
hol and ether.  It is obtained  by treating powdered gen-
tian  with  ether;  the  solution  is evaporated, and  the
residue treated with alcohol; this solution is then evapo-
rated, the new residuum  is  diluted in water, and a little
magnesia  added to saturate the acid ; this  is evaporated,
and  then  dissolved by ether, which unites with the gen-
tianine, and deposites the  salt  of magnesia;  by the  last
evaporation are  obtained small yellow  crystals which
appear to be in a state of purity.
  Germination.   The  vital  developement of a  seed
when it begins to grow.
  Glass.   (Verre.)   May be  regarded as a compound of
silex, soda, potash, and sometimes the oxides  of lead,
manganese, &c.
  Glass Common.  Consists of sand  100 parts, impure
soda  100, fragments  of old glass 100.  Glass may be
made of different colours by the addition  of coloured
metallic oxides: thus the peroxide of manganese gives a
fine violet colour; cobalt, an  azure blue ;  the  oxide of
                         20 
230
G  L U
 chrome, a greenish blue, &c.; the oxide of manganese-
 a beautiful red, &c.  The artificial stones for jeweller)
 are only glass coloured by metallic oxides.
   Glass of Antimony.  (Verre d'Antimoine.)   Trans-
 parent, of a hyacinth colour, very brittle; it is a compound
 of the oxide of iron, silex, alumine, a large portion of the
 protoxide of antimony, and a little of the  sulphuret of
 antimony.   It is prepared by melting at an intense heat
 the liver of antimony in large crucibles  of silicious clay ;
 one portion of the sulphur burns, and the metal is oxidized.
 It is evident that  the silex, alumine, and one part of the
 oxide of iron, are  derived from the crucibles, which were
 attacked during the  fusion of the  metal.   This glass is
 opaque if it  contain an excess of sulphur.   Vauquelin
 has  shown  that without iron, it would  be of a beautiful
 yellow ;  its transparency is owing to the silex.  The glass
 of antimony  is employed in the arts in  various ways ; it
 is sometimes used for the preparation of tartar emetic.
  Glauber's Salts.  See Sulphate of  Soda.
  Gliadine.   (Glia, glue.)   This substance has been
 recently discovered  in gldten.  It is of a yellow  colour
 and sweetish taste, is soluble in acids, alkalies, and alco-
 hol, but is not dissolved by water.
  Glucina.   (Glucine.)  See Oxide of Glucinum.
  Glucinum.  This metal is  only known in the state of
 an oxide.  See  Oxide  of Glucinum.
  Glue.  See Gelatin.
  Gluten.   Is soft, elastic, of a grayish white,  viscous,
 and almost tasteless.  In a dry state it becomes  brown
 and of a glassy brittleness ; submitted to a high heat, it
 decomposes like animal matter, leaving a brilliant and
voluminous charcoal;  exposed to dry  air, it is covered
with an oily surface, and becomes very  hard; but if the
air is  moist, it swells, putrifies, and diffuses a fetid odour
analogous to cheese.  It does not dissolve in cold water;
warm water destroys its tenacity and elasticity, without 
G O  L
231
dissolving it; it is insoluble in alcohol.  The vegetable
acids, especially concentrated acetic, muriatic, and some
other mineral acids, by the aid of a mild heat dissolve
gluten.  Charcoal and sulphuric and nitric acids act upon
it  as upon most  animal  substances.   M.  Taddei,  an
Italian chemist, does not consider gluten as an immediate
principle, but as  formed of two principles, gliadine, from
the Greek  gha, gluten, and zimome, from  zume, yest.
To obtain glu'en, a paste of wheaten flower is washed in
a large quantity of water, which carries offthe fecula, and
dissolves the albumen and  the sugar which were lodged
between the interstices of the gluten; it is pure when it
no longer disturbs the transparency of the water.  The
knowledge of gluten is due to Beccaria, an  Italian che-
mist.
   Glycerine.   A name proposed by Chevreul to desig-
nate a substance which Scheele has regarded as an imme-
diate principle, and called the sweet of oils.  Fremy and
Chevreul have demonstrated that it is formed by the action
of metallic oxides upon fat  substances.  It is said to consist
of 100 of oxygen, 70-70 of carbon, and 16-99 of hydro-
gen.  It is colourless, of a sweet taste, without any acid ;
its density is 1-252.  It  attracts moisture  from the air,
furnishes oxalic acid when treated with nitric acid, does
not ferment, and of course  does not yield alcohol.
   Gold.   (Latin aurum,  French  or.)  A metal, solid,
pure, yellow, very brilliant,  without taste or odour.  It
is one of the most ductile and the most malleable of metals,
One ounce of gold might be  beaten into leaf so thin as to
cover a fine silver wire of nearly fourteen  hundred miles
in length.   Its tenacity is  very great;  its specific gravity
is 19-257 ; it is less fusible than silver, being fused but at
a  heat of 32°  Wedgewood's  pyrometer.  It has been
melted in a reverberatory furnace;  submitted to a greater
heat, it does not  volatilize.   It  has no action, at any
temperature, upon  atmospheric  air  and  oxygen  gas, 
232
G O L
Most chemists even affirm that it is not oxidized by the
strongest electrical discharge ;  they regard the red pow-
der which is formed in this case as gold minutely subdi-
vided.   It unites to most of the metals, and to bromine,
chlorine, sulphur, iodine,  and phosphorus.   Gold  has
been known from the most remote antiquity; the alche-
mists regarded  it as the most perfect of metals;  they
called  it the sun or the king of metals.  It exists always
pure or alloyed with iron, silver, or copper ;  it is some-
times found  crystallized in cubes or octoedrons united in
little groups, but most commonly in  thin scales, spangles,
or grains, either in gangues or  isolated.  It occurs in
veins of "lead,  silver, and with  sulphuret of iron.  The
most extensive mines of this metal are those ot Mexico,
Peru, Transylvania, and  Hungary.   It is  found in  little
scales or spangles in the sands of Brazil, mingled  with
platina and the diamond, and also in the southern  United
States.  In Africa it is washed down from the mountains
by the rivers, and obtained from their sands.
  According to the calculation of  Humboldt, the old  con-
tinent furnishes  every  year 4000 kilogrammes of gold,
while America, much more rich, furnishes 18,000 kils.,
equal to 54,300,000 trancs, equal in all to 189,500,000 frs.
The operation of working gold mines  is carried on as
follows:  The  workmen  wash  upon  inclined tables
covered with cloth the auriferous or gold-bearing sands ;
they obtain for a residuum sands  more  and more rich;
these they treat  with  mercury; this  gives rise to an
amalgam, which they wash with many waters in order to
carry off the earthy matter.  This  amalgam is put into
sacks ot coarse cloth, and exposed to  heavy pressure.
The excess of the mercury passes through the interstices
of the  sacks, and a solid  amalgam  remains, from which
the gold is  obtained by heating, as the mercury being
very volatile is wholly disengaged.  The use of this pre-
cious metal as coin, for ornament, utensils, jewels, dec, is 
GUM
233
known in all civilized countries, and even among savages.
Gold coin usually contains 11 parts of gold and 1 of cop-
per. The purple of Cassius is obtained from the chloride
of gold precipitated by the proto-chloride  of tin.
   Grand Oeuvrk. A term synonymous with philosopher's
stone, used by the ale lemists to designate their pretended
process for making gold.
   Creen of ScHEELti.   (Vert de Scheele.)  A combina-
tion of the deutoxide of copper and vhe oxide of arsenic.
It is of a beautiful  apple-green colour, pulverulent, inso-
luble in water ; exposed to the action of fire, it diffuses a
strong odour of arsenic, and leaves a brown residue com-
posed of the deutoxide of copper.  Sulphuretted hydro-
gen  immediately changes Scheele's green into sulphurets
of copper and arsenic.   Some chemists admitting an ar-
senious acid, regard Scheele's  green as an  arsenite of
copper.   In order to obtain this  green, boil for half an
hour 11 ounces of white oxide ot arsenic with 2 pounds of
carbonate of potash; leave it to deposite, and pour into the
liquor a solution of 2 pounds of sulphate of'copper in 17
pints of water ; agitate the mixture, and Scheele's green
will  be precipitated ; let it drain upon a strainer, and wash
it many times, to separate the sulphate of potash ;  this
quantity produces 2 pounds of the green.  Braconnot has
recently published  a process by which a green as beauti-
ful as Scheele's may be obtained.  It consists in dissolv-
ing 8 parts of the white oxide of arsenic in 8 parts of the
potash of commerce, decomposing the solution by 6 parts
of the sulphate of copper, and mixing the precipitate with
3 parts of  acetic acid.   Scheele's green is used in the
painting of paper hangings and in oil painting.
   Gum.  {Gomme.)  An immediate product of vegetables,
uncrystallizable, colourless, insipid, inodorous, insoluble
in alcohol, soluble in water, forming with it a gelatinous
compound known under  the  name of  mucilage.   Gum
cannot be made to pass through the alcoholic fermenta- 
234
G U  M
 tion;  treated with nitric acid, it is changed  into mucn
 acid ;  submitted to the action of fire, it swells, and givef/ a
 product analogous to vegetable substances ; the alkalies
 and weak acids dissolve it; alcohol and the subacetate of
 lead precipitate it from all its solutions.  Gum is uni-
 versally diffused throughout the vegetable kingdom, being
 found  in all the parts of herbaceous plants, in many roots,
 and in all  fruits.  Many  trees,  particularly  the drupa-
 ceous, as the cherry, plumb, dec, naturally secrete gums,
 those which are used in commerce being of this kind.
 Gum varies much in its physical properties, according to
 the species of tree which furnishes it.
   The principal gums are : 1st, the Common Gum obtained
 from the peach, plum, cherry tree, dec  2d, Gum Arabic,
 which  flows naturally from the  Acacia  tree in Egypt,
 Arabia, and elsewhere  ; this  forms a clear  transparent
 mucilage with water. 3d, Gum Seneca, or Senegal; differ-
 ing but little from gum Arabic.  4th, Gum Adraganth or
 Tragacanlh, obtained from a small plant of the same name,
 in Syria.   These  gums are much  used both in the arts,
 and  in medicine.
   Gum Artificial.  Starch properly torrified or heated
 entirely  loses its  properties, and  is  transformed into a
 gummy matter, soluble  in  water.   This  solution is not
 affected by iodine.  It is distinguished from the proper
 gums,  in its  solution not being disturbed by the acetate of
 lead, and in not giving the mucic acid when treated with
 nitric acid.   (Saussure.)  This substance is employed as
 a substitute for the tapioca or cassada root, sago and other
 exotic  pastes.
   Gum Resins.   Substances of a colour very variable
usually of a  strong odour and a pungent taste, heavier
 than water, m which they are soluble ; they are soluble in
alcohol.   Water disturbs the alcoholic solution, precipi-
tating the resinous part, and according to Hatchett, pot-
ash and caustic soda dissolve the gum resins.   They  are 
GYP
235
formed of a concretion of several immediate principles.
They are  contained  in  the  vessels of plants,  and flow
from them with a milky appearance. The Euphorbia genus
and many of the umbelliferous plants furnish these gums
in abundance ; among  the  gum resins are Assafoetida,
Scammony, Aloes, Gum Ammoniac and Gamboge.
  Gunpowder.   (Poudre  a canon.)   It is a mixture of
the nitrate of potash, sulphur, and charcoal.  The violent
explosions produced by this composition are well known.
The manufacture of this powder is  carried on in large
buildings prepared for the purpose, called  by the French
poudrieres.   In selecting  the substances  great caution
must be used ; the sulphur should be as pure as possible,
the nitre should be cleared of all its  deliquescent matter,
the charcoal should  be recent, very  dry and light.  The
substances are then all pulverized and mixed in the follow-
ing proportions : first, for powder to be used in  war,
                  Saltpetre 75
                  Charcoal 12-50
                  Sulphur  12-50
  In powder for mining, dec, the proportions  are some-
what varied.
  It is very necessary that the materials should be mi-
nutely subdivided and intimately  mixed.   It should be
preserved in  very dry magazines.   Berthollet found that
the elastic product  afforded by the detonation of gun-
powder consisted of two parts of nitrogen, and one of car-
bonic acid gas.   The extrication and explosion of these
vapours are the cause of the effect of gunpowder.  This
composition was discovered by friar Roger  Bacon ; but it
is by many believed that the Chinese were previously
acquainted with it.    Those who  would farther  inquire
respecting the manufacture of this substance are referred
to the work of MM. Bollee and Tiffiout.
  Gypsum.   (Gypse.)   See Sulphate of Lime. 
•230
HON
                         H.

   Hartshorn (Spirit of.)  See Ammonia.
   Heat.   See Caloric.
   Hematin.  A crystallizable substance, white, bitter.
 and sharp to the taste ;  it was discovered by Chevreul in
 the Campeachy wood (Hematoxylon campechianum.)  To
 procure it, the powdered Campeachy wood should be di-
 gested with water at the temperature of 122°, the liquor
 is then evaporated  to dryness, and the  residuum put  into
 alcohol; in  two days it  should be filtered, and concen-
 trated by evaporating; a small quantity of water is then
 added and it is left to crystallize ; the crystals are puri-
 fied by washing in alcohol.   '*
   Hircine.  (From hircus, a  goat.)  A liquid substance
 which  exists in the fat of the goat and sheep.  It is much
 more soluble in alcohol than elaine, and is obtained by an
 analogous process.
   Honey.   (Miel.)  Is a substance varying  in colour
 from white to vellow, and sometimes to brown.    Its taste
 is sweet and aromatic.   It is prepared by bees, by intro-
 ducing into  their stomachs the viscous juice  and sugar
 which  they  collect in the nectaries of  flowers, after  re-
 maining  in  this laboratory for a time, it is deposited
 in the  cavities 'of the honey  comb.   It  is not known
 whether  honey is  a product  of nature or of these  in-
 sects, since  in the  nectaries of many plants is to be
 found a honey-like juice; in the morning, before the rising
 of the sun, many vegetables, such as the oak, pear tree,
 dec, are  covered  with an abundant  honey-like liquid
 which bees seek with eagerness.   Honey varies in its
 quality partly on account of the state of the atmosphere,
but chiefly from the different plants from which  it is  ex-
tracted.  All the labiate plants furnish excellent honey :
while some of the solance (of which natural family are the 
H Y D
237
 tobacco, potato, dec.) furnish  that which  is poisonous.
 Of the various kinds of honey, that of mount Hymettus,
 of mount Ida, of Cuba, and Mahon, is highly esteemed,
 having the appearance and consistence of the most beau-
 tiful sirup of sugar.  Honey is composed of two kinds of
 sugar, the one  liquid, the  other crystallizable analogous
 to the sugar of grapes; these united  with an aromatic
 substance, constitute honey in all its varieties.
   Hordein. (From hordeum, barley.)  An inodorous sub-
 stance, insipid, yellowish, pulverulent ;  it was discovered
 by Proust in great quantity in the flour of barley.   It dis-
 solves neither in hot nor cold water, nor alcohol.  It is ex-
 tracted in great quantities by washing a  paste of barley
 flour in a large quantity of  water, as described under the
 article gluten.   The hordein and starch are deposited,
 they are separated  by boiling  in  water, the starch dis.
 solves and the residuum is hordein ; some washings are
 then necessary in order to render it pure.   Nitric acid
 changes  it into oxalic and acetic acids.
   Horn.  A substance formed according to the analysis
 of Vauquelin of dried mucus, a small quantity of oil, and
 gelatine.
   Hydracids.  By these substances chemists understand
 those which result from the combination of hydrogen with
 a  simple combustible body  and which possess all the
 characters belonging to acids generally ; but five hydracids
 are well known :  viz.  Hydro-chloric, Hydro-sulphuric
 (sulphuretted  hydrogen,)  Hydriodic, Hydro-cyanic and
 Hydro-selenic acids.  (See each of these articles.)  Ac-
 cording  to  many chemists, the  hydracids  decompose
 whenever they are united to metallic oxides ; that is, the
 hydrogen of the acid  combines to form water with the
 oxygen of the oxide, and the two simple bodies being set
 free form a compound which is  a chloride, an iodide,
 iVc, according to the hydracid employed ; others regard
the compounds  which they  form  as  true  salts;  some 
238
H Y  D
agree with both these theories, by admitting that they are
salts while they remain dissolved,  but cease to be so
when dried.
  Hydrargyrated.  Of or belonging to mercury.
  Hydrates.  Hydroxide.   Hydroxure.    Proust  first
proposed the  name of hydrate, in order to designate the
compound which is  formed  when metallic oxides absorb
and  solidify  a  certain  quantity of water ;  most of the
hydrates lose the water which they absorb, those of potash
and  soda never part  with it, to whatever degree of heat
they may be  submitted.  Berzelius thinks that in the hy-
drates, the quantity of oxygen  contained  in the oxides
is equal to the quantity of oxygen contained in the water ;
Thomson believes  there may be  many hydrates of the
same oxide.  These compounds have in general a colour
different from the  oxides ;  for  example, the hydrate  of
lime is  white, while the oxide is grayish ;  that  of cop-
per is blue, while the dry deutoxide is brown, dec  Many
hydrates  are found formed in  bature, as the hydrate of
silex  or opal, the hydrate of alumine or  diaspore, and
many others.   Hydrates are obtained in laboratories, by
dissolving in water a salt whose  oxide is insoluble in this
fluid, pouring into the solution an excess of soda, potash,
or ammonia, then  washing the  flosculous  or gelatinous
substance.
  Hydriodates.   Salts resulting from the  combination
of hydriodic  acid with organic salifiable bases or ammo-
nia.  (For the metallic hydriodates, see Iodides.)   Under
the article Hydracids may be found the opinion of che-
mists relative to these last substances.
  Hydriodatk of Ammonia.  Crystallizes  in cubes, is
volatile.   Heated in close vessels it sublimes in the same
manner as sal ammoniac ; but if the  salt is heated in the
air, it undergoes a little alteration, taking a tinge more or
less deep, which is  owing to the iodine.  It is composed
of one volume of ammoniacal  gas, and one volume of 
H Y D
239
hydriodic gas. It is obtained by combining directly, liquid
hydriodic acid with ammonia.
   Hydriodide  of Carbon.   (Hydriodure  de Carbon.)
 A crystalline compound, white and friaible, which is ob-
tained by exposing to  the influence of solar rays  deuto-
carburetted hydrogen gas  with iodine, a  combination
soon takes place ; by  the aid of a solution of potash, the
excess of iodine is disengaged.  The hydriodide of carbon
 is soluble in ether and alcohol.  Thenard, on account of
the great . analogy  which  exists between  iodine   and
 chlorine, thinks that  this  is rather a hydro-carburet of
 iodine.
   Hydro-Bromate.   This term is used to designate the
 compounds formed  by the  union of hydro-bromic acid
with different bases.   These salts have not as  yet been
fully examined ; we  have however, hydro-bromate of am-
monia, a volatile white salt ;  that  of barytes  appears in
opaque crystals.  They  are both soluble in water.  The
hydro-bromate of magnesia does not crystallize, and is de-
composed when exposed to a high temperature.
   Hydro-Carburet of  Bromine is the combination of
bromine with olefiant gas, colourless, with a penetrating
odour  and sweet taste;  it is very volatile.   At a tem-
 perature of 22°, it becomes solid.
   Hydro-Carburet of Chlorine.  (Hydro-Carbure de
Chlore.)  Liquid, oily,  colourless, of a sugared taste,
an odour resembling that of ether ; it has no action upon
vegetable colours.  This liquid, exposed in a retort to the
action  of fire,  soon boils and becomes coloured; it is set
on fire by the  approach  of an ignited body; one  portion
of the carbon is burnt,  the other disengaged; the  hy-
drogen and chlorine combine to form hydro-chloric acid,
which  appears  in  white and  pungent fumes.   MM.
Robiquet and  Colin, who  investigated this substance,
found that  it  has a great  analogy with hydro-chloric *
ether;  they regard it as composed of nearly equal parts 
240
II Y  D
 in volumes of bicarburetted hydrogen and chlorine.   In
 order to procure the hydro-carburet of chlorine, a current
 of bicarburretted hydrogen gas is introduced into a large
 balloon or globe, and another current of chlorine in equal
 volumes ; the two gases unite without affording any other
 product.  This product is purified by washing in a small
 quantity of water.  Its  discovery is  due to the German
 chemists,  who called the Dicarburetted hydrogen, defiant
 gas.
   Hydro-Carburet of Iodine.   A white sweetish sub-
 stance, soluble in ether and alcohol, and crystallizing in
 prisms.  It is decomposed by heat, and gives out iodine.
 Faraday first obtained it  by  exposing olefiant gas  and
 iodine in the same receiver to the direct rays of the sun.
   Hydro-Chlorates. Muriates.  Combinations of hydro-
 chloric (muriatic)  acid with  ammonia,  and salifiable
 organic bases.   For the  metallic hydro-chlorates,  see
 Chlorides.
   Hydro-Chlorate of Ammonia. Muriate of ammonia.
 Sal  ammoniac.  A white  solid salt, of an acid taste ;
 somewhat elastic, ductile, unalterable by the  air;  cold
 water  dissolves about one  third  of its weight; boiling
 water dissolves a much greater proportion.  The solution
 carefully evaporated, crystallizes in  groups of prismatic
 plume-like needles.   Exposed to the action of caloric, if
 the heat is carefully applied, it sublimes  in rhomboidal
 forms ;  but if the operation is hastened, it condenses into
 a  mass more or  less compact.  The hydro-chlorate of
 ammonia calcined with lime disengages ammonia and a
 chloride of calcium, which remains fixed.  This salt is
 obtained from animal  products; it is found in  some vol-
 canoes and lakes.   There are various methods of manu-
 facturing it; among others is the following, discovered
 by Baume:  it consists in introducing the clippings of
wool, bits of leather,  or old shoes, into  iron cylinders,
 horizontally placed  in a reverberatory furnace.  At one 
H Y D
241
 'i»d of the cylinder is an aperture which may be opened
 to  introduce  substances;  at the  other is a large tube
 placed in a vessel of water, and  the apparatus is com-
 pleted  by a strait tube for the disengagement of the gas.
 The products are  usually the acetate and the hydro-
 cyanate of ammonia, oil, and a great quantity of the sub-
 carbonate of ammonia.   When the  operation  is  com-
 pleted, a certain  quantity of diluted sulphate of lime "is
 added.  Decomposition  soon takes place, giving rise to
 the formation of sulphate  of ammonia and  carbonate of
 lime, the one soluble, the other insoluble.   An excess of
 common salt is poured into the solution of the sulphate of
 ammonia; there is now a  formation of hydro-chlorate of
 ammonia and sulphate of soda.  This mixture is  evapo-
 rated to dryness, and then in a proper apparatus submitted
 to a slow heat;  after three days the sal ammoniac will
 have separated by sublimation.   This is whiter and more
 pure than that imported from Egypt.  Braziers, who use
it for separating verdigris from  copper, prefer that which
 is gray;  it is also employed in painting and medicine.
  Hydro-Chlorate of  Cinchonine.   Crystallizes in
 httle elongated prisms; it is much  more soluble than the
 sulphate of the same  base, and is composed of cinchonine
 100, hydro-chloric acid 8-90.
  Hydro-Chlorate of Morphine.  Very bitter,  crys-
 tallizable.  It is obtained like the preceding, by combining
 directly the base with diluted acid, and evaporating the
 salt by a slow  heat.
  Hydro-Cyanates.  Salts resulting from the combina-
 tion of hydro-cyanic acid with ammonia  or vegetable
 bases.  For metallic hydro-cyanates, see Cyanides.
  Hvdro-Cyanate of  Ammonia.  Its  crystals  are in
cubes, or resemble fern leaves ; it is excessively volatile
and easy to be decomposed by the action of fire.  It is
obtained by a direct process.  This salt has been studied
only by Gay-Lussac.
                         21 
242
HYP
  Hydro-Ferro-Cyanates.  Combination of  the  hy-
dro-ferro-cyanic acid with bases.   For the metallic  hy-
dro-ferro-cyanates, see Ferro-Cyanates.
  Hydro-Ferro-Cyanate of Ammonia.   This salt  is
prepared like the ferro-cyanate of lime.  Exposed to the
action of heat in a retort, the hydro-cyanate of ammonia
sublimes, and the residue, which is composed of the cya-
nide of iron, decomposes into nitrogen gas, and a carbu-
ret of iron, which, when  heated to redness, unite.  (See
Ann. de Chimie, et de Physique, tome XV.  p. 225.
  Hydro-Fluates.   These are salts formed by the com-
bination  of hydro-fluoric acid with the  pure  alkalies.
With muriate of lime a thick precipitate is  formed, which
yields, when  heated with strong sulphuric acid, the hy-
dro-fluoric acid.
  Hydro-Fluate  of Ammonia.   This neutral salt  is
soluble in water, slightly so in alcohol; it acts rapidly
upon glass even when dry.   It is prepared by mixing  in
a platinum crucible,  one part  of muriate of ammonia,
and 2i  parts  of fluoride of  sodium, in a state of dry
powder; on  applying a  gentle heat, the hydro-fluate ot
ammonia sublimes, and condenses in small prisms on the
lid of the crucible, which, during the operation, must  be
kept cool.
  Hydro-Fluate of  Lithia.  The acid and neutral hy-
dro-fluates  of this substance,  are  sparingly  soluble  in
water.
  Hydro-Fluate   of   Potassa.   (Bi-Hydro-Fluate.)
Forms rectangular crystals.  It is  soluble in water, de-
composes by  heat, and  reddens  vegetable  colours.  It
consists of two equivalents of acid, and one of potassa.
The hydro-fluate contains only one portion of acid, united
to one of potassa ;  it is prepared by super-saturating car-
bonate of potash with hydro-fluoric  acid, evaporating the
solution  to dryness, and heating it until  the  excess  of
acid is expelled.   This salt has the properties of alkalies. 
H Y  D
243
  Hydro-Fluate of Soda.  The acid hydro-fluate crys-
tallizes in transparent rhombs, has a  sharp  sour taste,
and  is sparingly soluble  in cold water.  The neutral,
commonly crystallizes  in  cubes, is almost insoluble in
alcohol, is sparingly soluble in water even at an elevated
temperature.   These  salts are  prepared  like the pre-
ceding.
  Hydrogen.   {Hydrogene.)  A word derived from the
Greek, signifying to produce water, which it does by an
union  with  oxygen.  A gas,  colourless, insipid, inodo-
rous.  Its specific gravity  compared to that of air, is but
0-0688.  Upon this property is  founded the theory of
aerostatic balloons ; it  also enables  the chemist easily to
transfer the  gas from one bell-glass to another, as by its
levity it takes the upper part, pressing down the atmo-
spheric air with which  the bell-glass  might be filled, in
the  same  manner as gases usually rfse through water,
and fill the receivers.  Hydrogen gas,  though itself very
inflammable, extinguishes combustion.
  This gas experiences no alteration by the most intense
heat, except in expansion.   At the  ordinary temperature
it does not combine with oxygen ; these gases may for a
long time remain mixed without uniting; but if the tern-
perature is raised to a red  heat, combination takes place
in the  proportion of 1 part  of hydrogen, and one of oxy-
gen, forming water.  Combination  is also instantaneous,
if into a eudiometer containing  a mixture of these two
gases, an electric spark is introduced.   If, after having
over water filled a flask with two parts of hydrogen and
one of oxygen, and surrounded it with a cloth, a lighted
taper is presented  to  the opening  of the flask, a violent
detonation will take place ; this is owing to the liquefac-
tion of the two gases,  and also  to the expansion of  the
water, which, brought into a state of vapour by the heat,
occupies much more space than was required for the sim-
pie mixture of the  gases.   Instead of mixing the gases 
244
H Y  D
 in a flask, they may be introduced into a vessel contain-
 ing soap-suds ;  this is  done by first filling with the gases
 a bladder furnished with  a stop-cock; the  soap-suds is
 made  to froth,  and the surface  becomes covered with
 bubbles, by the introduction of the gases; these bubbles
 will  be set on fire, and produce  a series of detonations,
 by applying  a lighted  taper, which may be attached to
 the end of a stick.
  Biot has shown that  a combination of oxygen and hy-
 drogen gases may be effected by powerful compression.
 Notwithstanding the inflammable nature of hydrogen, it
 cannot take fire through a close  metallic net-work.  Sir
 H. Davy, in discovering this  fact, was led to the inven-
 tion of his safety lamp,  which is of the highest importance
 to  miners, whose lives, previous to this invention, were
 often sacrificed by sudden explosions of this gas, caused
by its contact with the flame of their torches.  Dobereiner
has recently  discovered, that  in directing  through  atmo-
 spheric air a current of hydrogen upon  spongy platina,
 palladium, or rhodium, the metal reddens and forms water.
 Hydrogen unites with sulphur, chlorine, carbon, phospho-
rus, selenium, iodine, nitrogen, potassium, tellurium,  and
 arsenic  This  gas is, of all combustible  bodies, that
which  in burning produces  the  most heat;  when  the
flame of hydrogen  mixed with oxygen is directed upon
metallic substances, there  are few that  are not imme-
 diately fused.
  Hydrogen  is one of the most generally diffused sub-
stances in  nature;  it enters  into the composition of all
 animal and vegetable substances, of water, all the hydra-
cids, of ammonia, dec.   It is  obtained  as  follows : Into
a flask with  two  tubulures are put pieces of zinc, with a
little water ; to one of the tubulures is fitted a tube which
 communicates with  the pneumatic cistern ; through  the
 other tubulure is  poured sulphuric acid;  a  lively effer-
 vescence occasioned by the decomposition of the water 
H Y  D
245
 lakes place; the tubulure is left unstopped  for a short
 time, in order that the first portions of gas, which  are
 mixed  with atmospheric air, may  pass  out;  receivers
 filled with water are placed on  the  shelf of the cistern:
 the gas by its levity displaces the water, and fills the re-
 ceivers.   Hydrogen gas may also be prepared with iron
 filings.  The aeronauts follow the same process in infla-
 ting their balloons.   This gas was discovered in the be-
 ginning of the 17th century, and was studied in 1777 by-
 Cavendish, who called it inflammable air.
   Hydrogen Arseniuretted.   (Hydrogene Arsenique.)
 A colourless gas, of an insupportable odour;  its specific
 gravity according to Davy is 0-5552.  It has no action upon
 vegetable colours;  its action upon the animal economy
 shows it to be among the most deleterious of all substances.
 Professor Gehlen, having breathed a certain quantity of this
 gas, was seized with vomiting,  chills, great debility, and
 after nine days died in appalling agonies.   Arseniuretted'
 hydrogen seems  not to be  decomposed at the ordinary
 temperature.  M. Stromeyer liquefied it, by exposing it
 ♦o a cold below zero ;  heated with a  sufficient quantity of
 oxygen gas, it is transformed into water and deutoxide of
 arsenic.  When a mixture of arseniuretted hydrogen and
oxygen are inflamed in a flask, there is a powerful deto-
 nation,  a formation of water, and a deposite either of the
oxide of arsenic  or the hydruret  of arsenic.  Chlorine
 rapidly  decomposes it, the hydrogen uniting with it to
 form  hydro-chloric acid.  This gas, according to  Stro-
 meyer,  is composed of 10-89 of arsenic, and 1-24 of hy-
 drogen.
   It is obtained by  exposing to gentle heat a  mixture of
 equal parts of tin  and arsenic  with four or  five  parts
of hydro-chloric  acid; gas disengages by the decom-
position of the acid,  and  the chloride of tin remains.
In order to avoid  respiring it,  it  is   collected in  flasks
over  the hydragiro-pneumatic  cistern.   This gas has 
246
H Y D
 been the object of the successive researches of Scheele.
 Proust, Tromsdorff, and Stromeyer.
   Hydrogen  Borruretted.  Although the affinity  of
 boron for hydrogen is slight, yet by mixing 1 part of bo-
 racic acid with 4 parts of iron-filings, exposing them in a
 crucible  for half an hour,  dissolving the resulting mass
 in hydro-chloric (muriatic) acid, this gas is  produced.
 It burns  with  a  yellow  flame and white fumes,  giving
 out an  odour like arsenic.  It was discovered by Gmelin.
   Hydrogen Carburetted (Deuto.)  See Carburetted
 Hydrogen (Deuto.)
   Hydrogen Carburetted (Per or Quadri.) See Car-
 buretted Hydrogen (Per.)
   Hydrogen Phosphuretted (Per.)  See Phosphurel-
 led Hydrogen.
   Hydrogen  Potassuretted.   See Potassuretted Hy-
 drogen.
   Hydrogen Selenuretted.  See  Selenuretted Hydro
 gen.
   Hydrogen Sulphuretted.  See Sulphuretted Hydro-
 gen.
   Hydrogen Telluretted.  See Telluretted Hydrogen.
   Hydro-Seleniates.  Berzelius has  ascertained that
 hydro-selenic acid unites with the alkalies, forming soluble
 compounds which resemble the hydro-sulphates, and pre-
 cipitate the salts of the common metals.   They are how-
 ever but  little known.
   Hydro-Sulphates.   {Hydro-Sulfates.)   Hydro-sul-
phurets.  Combinations of sulphuretted  hydrogen with
ammonia and  vegetable alkalies.  For  metallic hydro-
 sulphates, see Sulphurets.
   Hydro-Sulphate of Ammonia. (Hydro-sulfate d'Am-
 moniaque.)  Hydro-sulphuret of ammonia.  A white salt,
translucid, crystallizing in transparent scales.  It is inso-
luble, but so volatile that at the  ordinary temperature  it
sublimes  to the upper part  of the flask in which it is con 
H  Y D
247
 Lamed.  It is decomposed in the air by absorbing oxygen,
 and passes to the state of a sulphuretted  hydro-sulphate.
 This salt is  formed in nature by a decomposition of ani-
 mal substances;  it is obtained in laboratories by com-
 bining directly ammoniacal gas with sulphuretted hydro-
 gen at a very low temperature.   For  this purpose, the
 two dry gases are introduced  by tubes into a flask sur-
 rounded  with ice;  this  flask has a  third tube which is
 placed under mercury, in order  to give  vent to the ex-
 cess of the gases, and at the same time avoid contact with
 the air.   As the hydro-sulphate of ammonia is often used
 as a re-agent, it is sometimes prepared in a liquid state
 by saturating liquid ammonia with a current of sulphuret-
 ted hydrogen.
  Hydro-Sulphurets.   See Hydro-Sulphates and Sul-
phurets.
  Hydrurexs.  (Hydrures.)  Under  this name are de-
 signated the  solid products not acid,  formed by a com-
 bination of hydrogen and a simple substance.
  Hydruret Ammoniacal of Mercury and  Potash.
 Thenard and Gay-Lussac have  given this name to a com-
 pound, discovered by M. Seebeck, consisting of mercury,
 potassium, hydrogen, and ammonia.  When into concen-
 trated liquid ammonia is  introduced  a  liquid amalgam of
 mercury and potash, or of mercury  and soda, the amal-
 gam increases greatly in volume, takes a butter-like con-
 sistence, and preserves its metallic brilliancy.  Accord-
 ing to Thenard and Gay-Lussac, the  water of ammonia
 is decomposed, its oxygen unites to a  portion of the po-
 tassium or sodium, in order to form potash or soda, which
 dissolves, while the hydrogen unites to  the amalgam, thus
 forming  the  hydruret.  (See  Traite de  Chimie de M.
 Thenard.)
  Hydruret of Arsenic  (Hydrure d'Arsenic.)  Red-
 dish brown,  solid,  inodorous,  insipid; it is not decom-
 posed bv red heat;  it absorbs oxygen at a high tempera- 
24*
H Y  G
 ture, becoming water and the deutoxide of arsenic.   It
 is obtained by passing a little chlorine into flasks contain-
 ing arseniuretted hydrogen ; there is an immediate for-
 mation of hydro-chloric acid ;  at the same time the hy-
 druret of arsenic is deposited on  the sides of the vessel.
 Discovered and  studied by Davy, Thenard,  and Gay-
 Lussac.
   Hydruret of Potassium.  (Hydrure de Potassium.)
 Gray, solid,  without  a  metallic  appearance,  is decom-
 posed by a slow mild beat;  all the hydrogen disengages.
 leaving the potassium free ; mercury, assisted by heat,
 easily decomposes  it; the hydrogen is disengaged, and
 the  mercury amalgamates with  the  potassium.   Disco-
 vered by Thenard and Gay-Lussac.
   Hydruret of  Sulphur.   (Hydrure  de Soufre.)   A
 thick liquid, heavier than water,  of an  odour  and taste
 analogous to sulphuretted hydrogen.   It may be decom-
 posed into sulphur and sulphuretted hydrogen; it is there-
 fore supposed to be composed of two substances.   It is
 obtained by pouring hydro-chloric acid into a solution of
 sulphuret of potassium ; the hydruret of sulphur forms
 at the bottom of the vessel.  It can be preserved only by
 mixing  it with it a little hydro-chloric acid, and keeping
 it in a bottle closely corked.
   Hydruret  of Tellurium.   (Hydrure  de  Tellure.)
 Discovered by Ritter ; it is very little known ;  it  is solid,
 and in appearance resembles the hydruret of arsenic.  Its
 discoverer obtained it by attaching to the extremity  of
 the negative wire of the  voltaic pile a small fragment  of
 tellurium, plunging  this  into water, and there forming a
 communication with the extremity of the positive wire.
 By the  decomposition of water,  hydrogen in  a nascent
state combines with  tellurium.
  Hygrometer.  (From  the Greek words ugros moist,
and metron a measure.)   An instrument to measure the
degrees of moisture  in the atmosphere. 
I N D
249
  Hypo.   From the Greek upo, under, or less;  thus,
hypo-sulphuric acid contains less oxygen than sulphuric
acid, dec.  The opposite of super, above.
  Hyosciamin.    (Hyosciamine.)    A  name given  by
Brande to a substance which is obtained from the black
hen bane (Hyosciamus niger) by means of potash, and by
him believed to be of an alkaline nature.
                           I.

   Indigo. Colouring matter, solid, without taste or odour;
 of a purple blue, volatilizes partially with heat, under the
 form of violet vapours similar to those of iodine.   It nei-
 ther  dissolves  in water, ether, or alcohol, except when
 the latter  is heated.  It dissolves by the aid of gentle
 heat in concentrated sulphuric acid ;  its use in dyeing is
 in part founded on this property.   Nitric acid dissolves it
 easily.   If by using deoxygenating substances a portion
 of oxygen  is  taken  from indigo,  it loses its fine colour,
 becomes  yellow, and can  then  be easily dissolved in
 slightly alkaline water ;  if this solution is agitated in con-
 tact with the atmosphere, it regains  the  oxygen  it had
 lost,  and becomes blue.  Sulphuretted hydrogen appears
 to be the substance which deoxygenates it with the most
 facility, acting upon it at the ordinary temperature.  In-
 digo  is extensively employed  in dyeing; Gay-Lussac
 used  it to determine with precision the degree of strength
 of the chloride of lime.   It exists in the leaves of many
 species of plants, but is chiefly obtained from the Indigo-
fera  tinctoria.   The leaves of this plant are fermented
 under water in  large tubs; the liquor  becoming acid, is
 covered with irised pellicles; it is  then decanted, and
 mixed  with lime water.  A deposite  is formed, which,
 when washed and dried, is the indigo of commerce.  In 
250                    I O  D
order to obtain it perfectly pure, it should be heated in u
closely covered silver crucible.   It soon volatilizes, and
deposites purple crystals.   Jnthis state it is composed of
carbon  73-26,  azote  13-81,  oxygen 10-43, hydrogen
2-50.  (Leroger and Dum^s )
   Ink.    (Encre.)   Ccnunon ink  is  water which  In
means of gum holds in suspension a  combination of tan-
nin,  gallic acid, and  oxide of iron ;  this combination is
easily obtained by macerating in  a  sufficient quantity of
water equal  parts of powdered nutgall and sulphate of
iron, aftewards adding gum m suitable proportions.
   Ink for Printing.  (Encre des Imprimeurs.)  A mix-
ture  of oil and lampblack.
   Ink Sympathetic  (Encre de  Sympathie.)   Prepa-
rations for writing on paper, which become visible either
by contact with some other substance, or by being heat-
ed.  In the  first case, if a sciution of a salt of lead is
used for writing, the letters are not visible until exposure
to a  sulphurous vapour readers them  black.  In the  se-
cond case, a solution of hydro-chlorate (muriate) of  co-
balt  being rose-coloured,  cannot be  seen  upon rose-
coloured paper, until  the letters  are  heated; they then
become blue.
   Inulin.  (Inuline.)  A vegetable substance, white and
pulverulent, presenting physical and chemical characters
similar to starch.  It however differs from it  in some
respects, as  when dissolved in warm water it precipitates
on cooling and does not  become  b'ue by  the action of
iodine.  It was discovered by Rose  in the parts of  the
elecampane, (Inula hele-niui'i) and has since been found
in those of several other plants.  It is obtained by making
a strong  decoction of the roots, leaving it  to  stand'  and
then washing the deposite, which  is  inulin,  with cold
water.
   Iodates.   They are  little soluble in water,  most of
them are  wholly insoluble; all are  decomposed by red 
I O  D
251
 heat, by sulphurous,  sulphuric, and muriatic acids and
 powerful oxides, if not at the ordinary temperature, with
 a little increase of heat.  In the iodates the quantity of
 the oxygen of the oxide is to the quantity of the  oxygen
 of the acid as 1 to 5.
   Iodate of Ammonia.  (Iodate d'Ammoniaque.)   Gay-
 Lussac, to whom we are indebted for the discovery and
 study of its properties, obtained it  by saturating  iodic
 acid with liquid  ammonia.   It  is precipitated  in  little
 granular crystals, which on burning detonate with a hiss-
 ing noise, diffusing vapours of iodine.
   According to this celebrated chemist, it is composed of
 iodic acid 100, ammonia 10-94,  or in volume of 2 vol. of
 ammoniacal gas, 1 of vapour of iodine, 2-50 of oxygen.
   Iodate of Barytes.   (Iodate de Baryte.)    White,
 pulverulent,  insoluble..   It is obtained  by  double  de-
 composition ;  it consists of 100 of acid, 46-34 of barytes.
   Iodate of Lime.  (Iodate de Chaux.)   Crystallizes in
 small quadrangular prisms.
   Iodate of Potash.  {Iodate de Potasse.)   White, crys-
 talline, fuses upon burning coals, dissolves in 14 parts of
 cold water; is formed of 77-754 of acid and 22-246 of
 the base.  It is obtained by agitating a mixture of iodine
 and a solution of caustic potash with water.   A very solu-
 ble hydriodate and an almost insoluble iodate are formed:
 this is purified with many  washings with alcohol.   In
 order to obtain it perfectly pure,  it  must be  dissolved in
 boiling water;  acetic acid is added to saturate an  excess
of alkali; it is then  crystallized  and  the washings  with
alcohol repeated  to  carry off* the acetate which may re-
 main.
   Iodate of Soda.   (Iodate de Soude.)  Crystallizes in
little  prisms, often in groups, presents similar characters
to the iodate of soda, and is obtained in the same manner :
it consists of 84-1 of acid and 15-9 of the base.
  Todate of Strontia.   Dissolves with diflicultv. 
252
I O  D
   Iodine.  A simple body,  solid,  brittle, of an odour
 analogous to chlorine, colour bluish gray, possesses  a
 metallic lustre and a lamellar texture.  Its specific gra-
 vity is 4-946.*  It colours  the  skin a brownish yellow.
 Iodine is volatile;  if submitted to the action of heat  it
 melts at 224°.  Its vapour is  of a beautiful violet colour.
 It exhibits  the electrical property  of oxygen in a high
 degree; of course these two bodies cannot be directly
 combined.  Its affinity for hydrogen, on the contrary,  is
 very great; and it  combines with  most  of  the  simple
 bodies.  It  decomposes water through the medium of an
 alkali, acts  also upon the greatest part of hydrogenated
 substances.   It unites with  starch  in different  propor-
 tions, giving a beautiful blue colour to the combinations.
 For the  discovery  of this substance  we are indebted to
 M. Courtois,  a manufacturer of soda at Paris,  but for
 the  investigation of its  properties  to Gay-Lussac.  Ii
 exists in sea-weeds and sponges.  It is usually obtained
 from the mother-water  furnished by the  soda  of sea-
 weed ; these waters contain iodine  united to hydrogen
 and potash; they are treated with sulphuric acid and the
 peroxide of manganese, the  mixture being  put into,  a
 retort  and  slightly  heated  iodine  is deposited  in the
 adopter and neck of the retort.  It is purified by  dis-
tilling  it again with a mild  alkaline  water.   It  is  em-
ployed in medicine and as a re-agent in chemistry.
   Iodide of Ammonia.  (Iodure d'Ammoniaque.)   Was
discovered by Colin.   It is a viscous liquid, shining, of a
darkish brown colour; in contact  with water it is trans-
formed into  a soluble hydriodate and a fulminating iodide
of azote which is precipitated.   The  iodide of ammonia
is  obtained by bringing ammoniacal gas in contact with
iodine.
   Iodide of Nitrogen.  (Iodure d'Azote.)   Pulveru-
lent, dark brown, detonates by the slightest shock :  it is
* According to Thompson it is 30844. 
I 0 D
253
obtained by treating iodine  at  the ordinary temperature
with liquid ammonia, a soluble hydriodate of ammonia is
formed, and iodine is precipitated.  It  is collected upon
a  filter,  and  is  composed  of  5*8544  iodine, 156-21
azote (nitrogen), or in volume of 1 of azote, and 3 of
vapour of iodine.
   Iodides Metallic   (Iodures Metalliques.)   Iodine
combines with most  of the metals; having considered
the hydro-chlorates (muriates) as chlorides, and the hydro-
sulphates as sulphurets, we shall necessarily consider the
hydriodates as iodides ;  according to Thenard the iodides
which can dissolve in water become by this process hy-
driodates ; according to Dulong many iodides can be dis-
solved in water without producing its decomposition.  As
all the phenomena which these bodies present may be ex-
plained according to either hypothesis, we use the terms
hydriodates and soluble iodides as synonymous.
   Iodide of Antimony.  (Iodure d'Antimoine.)  Is ob-
tained by treating antimony with an  excess of iodine.
In contact with water it decomposes, giving place to hy-
driodic acid which dissolves, and the oxide of antimony       •,
which is precipitated ; chlorine decomposes it at a high
temperature;  concentrated nitric  acid  disengages  the
iodine and the antimony is oxidized.
   Iodide of Barium.   (Iodure de Barium.)   Very solu-
ble in water ;  crystallizes in acicular  prisms.  Exposed
to an elevated temperature  and submitted to contact with
atmospheric air, it absorbs oxygen ;  the  barium oxidizes,
a  portion of iodine is disengaged, and  a sub-iodide of ba-
rytes is formed.   Iodide of barytes is obtained by agitat.
ing iodine in a solution of barytes, filtering it in order to
separate the insoluble iodate, and crystallizing the iodide
(hydriodate) ; it is afterwards moderately heated to drive
off the water of crystallization, which  we  must consider
as combined with it if we regard it as a hydriodate.
                          22 
254
I  O  D
   Iodide of Bismuth.  (Iodure de Bismuth.)  Is obtain'
ed like that of antimony, or rather by pouring a solution
of the iodide of potassium into a solution of the nitrate of
bismuth ; nitric  acid drives off the  iodine and forms a
nitrate.
   Iodide of Calcium. (Iodure de Calcium.)   Very solu-
ble in water, susceptible of crystallization ; it is obtained
by a process similar to that of the iodide of barium, and is
affected by heat in the same manner.
   Iodide of Copper. {Iodure de Cuivre.)   Little known ;
it  may be prepared  either directly or by double decom-
position.
   Iodide of Iron.   (Iodure  de Fer.)  Brown,  styptic
very soluble;  may  be prepared directly, or rather by
bringing iron and iodine in contact,  at the ordinary tem-
perature,  through the medium of water.
   Iodide of Lead.  (Iodure de Plomb.)   Little known,
is  obtained by pouring a solution of the iodide of potas-
sium into a solution of the acetate.
   Iodide of Mercury.   (Iodure  de Mercure.)  Mercury
combines with iodine in two proportions:  Proto-iodide is
of a greenish yellow colour, insoluble in water ;  it is ob-
tained  by pouring a solution of the  iodide of potassium
into a solution of the  proto-nitrate of mercury, filtering
and washing the precipitate.   Deuto-iodide is of a beau-
tiful red, fusible and susceptible of volatilizing ; it is then
lamellar and very brilliant, and is obtained by pouring a
solution of the iodide of potassium into a solution of the
deuto-chloride of mercury.  It is employed in medicine.
   Iodide of Potassium.  (Iodure de Potassium.)  Colour-
less, susceptible of crystallization,  fusible, and volatile
above red heat; very soluble  in water, decomposable by
nitric and sulphuric acids.  It is formed  of 100 of mer-
cury and 20-425  of iodine.  It is obtained by agitating
iodine in a solution of caustic potash,  filtering it and evapo-
rating the liquor. 
I R  O
255
   Iodide of Silver.  {Iodure oVArgent.)  It is obtained
like that  of antimony, is  insoluble in ammonia, has no
action upon  water, is decomposed by chlorine, by nitric.
and concentrated sulphuric acids.
   Iodide of Sodium.    (Iodure de Sonde.)  Colourless,
very soluble in water, crystallizes  in rhomboidal prisms
which contain  much of the water  of crystallization ; it
loses this water on being exposed to heat, fuses and vola-
tilizes.  It is obtained like the iodide of potassium.
   Iodide of Strontium.  (Iodure  de Strontium.)  Very
soluble, crystallizes in  acicular prisms ;  exposed to  the
action of  caloric, it  exhibits the same phenomena as  the
iodide  of barium, and is obtained in the same manner.
   Iodide  of Tin.   (Iodure d'Etain.)  Is  prepared like
that of antimony, and possesses similarproperties.
   Iodide  of Zinc  {Iodure de Zinc.)   Is obtained by
heating zinc with an excess of iodine, or by boiling water
with iodine  and  an excess of this  metal;  afterwards
heating the  uncrystallizable liquor which  resulted from
the first operation ;  when it has lost its water  of  crystal-
lization it  volatilizes, and crystallizes  in very fine colour-
less prisms;  but  if heated in  contact with the air, it is
transformed into iodine and an oxide of zinc.
   Iridium.   This, of all  metals,  combines  with other
substances with the greatest difficulty ; it is a white metal,
not fusible ;  its density is not known, it has hitherto been
combined with but a small number of  substances.  Nitro-
muriatic acid does not act upon it;  potash acts upon it at
a very high  temperature.  It is a  very rare  substance.
and has been found only in combination with osmium in
platina ore.  (See Platina.)
   Iron.   (Fe-r.)  A metal of a bluish gray colour, some-
times  granular,  sometimes lamellar,  very ductile  and
malleable.  It  has  great tenacity,  is very magnetic; its
specific gravity is 7-788.   It melts  at a high temperature.
*ts affinity for oxygen is such that  at a high temperature 
256
I R O
it  takes it  from potassium and even sodium, and form-
many oxides even at at the  ordinary temperature.  It is
the only metal that has hitherto been combined with car-
bon ;  this combination  is called  plumbago; steel is a
per-carburet of iron.  Iron combines with most combusti-
ble non-metallic substances, and forms alloys with man\
metals ;  it decomposes water  at  the  ordinary tempera-
ture,  only in  proportion  as this water  contains air  or
oxygen ; a low oxide is thus formed, which by its contact
with the  metal appears  to develope sufficient electricity
to  continue the decomposition.   Nitric acid dissolves it,
producing a certain quantity of the nitrate  of  ammonia.
The solution of the  protoxide of iron forms with the  alka-
lies a white precipitate Which  becomes green by contact
with the  atmosphere, afterwards a darker green, and then
red.  It forms with  the ferruretted hydro-cyanate of pot-
ash, a white precipitate which  becomes  blue  by contact
with  the air ; it is not precipitated by nutgalls, but the
solution is coloured by the air a violet blue.  At the second
degree of oxidation the solution of iron is precipitated
dark green by the  alkalies, sky blue  by the  hydro-cya-
nate of potash, and  deep blue by nutgalls. Iron is found in
nature in various states  ; those in which  it is wrought arc
native  iron,  carbonated, oxidulated, oligist, hematite,
dec.   It is found  combined with sulphur and arsenic in
the state of  a salt, but these last two minerals are not
wrought.  In order to obtain iron from its  combinations,
the ore is roasted, or pulverized  when  it  is earthy, and
treated with  charcoal at a very high temperature, in the
peculiar furnaces,  called hauls fourneaux.    When  the
mineral is siliceous, carbonate of lime is added (called
cussine)  in order to facilitate the  fusion ;  but if silex is
wanting, an argillaceous solvent (called erbue) is added ;
in proportion  as the iron is reduced  it passes into the
crucible  or lower  part  of the  high  furnace ; and  when
this part is filled, the melted matter flows into a channel 
JUP
25*
 made in the  sand, and the elongated mass which  results
 is called the gense, or melting ; this  is exposed to a very
 high temperature in order to burn a little carbon which ii
 contains, and to reduce a quantity of oxide ; it is many
 times  successively hammered, in order to separate the
 vitrified matter (laitier) which is  coloured green  by the
 oxide  of iron.
   Iron White.  (Ferblanc.)  Ancient name for  tin.


                          J.

   Jelly Vegetable.  (GeUe Vegetate.)  Vegetable jelly.
 I colourless  substance, of an appearance similar to gum,
 soluble in hot water, and almost insoluble in cold. It exists
 abundantly in some  fruits, such as apples, cherries, cur-
 rants,  dec ; it is very difficult to  obtain  it in a state of
 purity, as a little of the  colouring matter of the fruits is
 always retained.  By being left too long in contact with
 boiling water, it loses its gelatinous appearance.  It ap-
 pears to contain a little nitrogen, which may be  owing to
 the small quantity of yest (ferment) which jelly contains.
   Jet.  (Jais.)  So called from the river Gaza in Asia,
 from whence it came.  It is a black bituminous coal, hard,
 compact, found  in great  abundance  in various parts of
France, Sweden, Germany, and Ireland.  It is brilliant
and vitreous  in its fracture, and capable of taking a good
polish  by friction;  it attracts light substances, and ap-
pears electric, like amber; hence it has been called black
amber.
  Jupiter.   A name given by the ancient chemists to
tin, because supposed to be in some measure, under the
influence of that planet.
22* 
258
L  A M
                         K.

  Kali.   (An Arabian word.)  See Potash.
  Kelp.   Incinerated sea-weed.
  Kermes.  See Hydrated Sulphate of Antimony.
  Kinates.  Combinations of kinic acid with  bases.
These salts are scarcely known, they are not used.
  Kinine.   See Quinine.
  Kino.   A resin obtained from a tree growing in Africa :
it resembles in appearance the resin called dragon's blood
(Sanguis draconis.)   It is considered one of the most effi-
cacious astringent medicines of the vegetable kingdom.


                        L.

  Laboratory.  {Laboratorium.  From labor,  labour.)
In chemistry it signifies a place properly fitted up for the
performance of chemical operations.
  Lac   (From  Lac, lactis) Milk.    Also a vegetable
substance, obtained from a plant* in the East Indies ; it is
sometimes called gum-lac, stick-lac, shell-lac, dec.
  Laitier.   A name by which the French understand
the vitrified matter which is found  on  the surface of iron.
in a state of fusion.
  Laiton.   Brass.   An alloy of copper with zinc.
  Lamp Philosophic. The old chemists gave this name
to the burning hydrogen gas which they caused  to issue
from a matrass, through a small straight tube ; when the
hydrogen gas  had driven the  atmospheric air from the
matrass, they applied a  lighted taper to the gas ;  this
formed a lamp which burnt until all the gas was diseno-ap-ed.
* Crottn lacciferum ; or Croton, bearing lac. 
LEA
259
 f his experiment is made with  iron filings, and diluted
 sulphuric  acid, the same as in obtaining hydrogen gas.
   Lead.  {Plomb.)  A metal of a bluish white colour,
 brilliant,  giving  a disagreeable  odour on  rubbing ; the
 specific gravity is 11-352. Lead is malleable and ductile,
 but it posesses little tenacity, very little elasticity and is
 little sonorous.   It is one of the  most fusible of metals.
 it melts much below red heat, and crystallizes on cooling.
 Atmospheric  air and dry  oxygen  gas have  no  action
 upon it; but if these gases  are humid, they soon tarnish
 it, covering it with a gray crust of the protoxide of lead :
 at a high temperature it absorbs  the oxygen of the air ;
 in fusion it is covered with a yellow crust,  which is soon
 replaced by a second, if this is removed.  Boron, hydro-
 gen, nitrogen, and carbon have no action upon lead ; but
 it combines easily with phosphorus,  sulphur, iodine, chlo-
 rine, selenium, and many other metals. Lead was known
 in the most ancient times; on  account of  its abundance
in nature, it has been the object of many investigations :
 the alchemists tortured  it in the hope  of transforming it
 into silver ; they called it Saturn.   It is found in nature
 in three  states :  1st,  in the  state of a salt;  2d,  as  an
 oxide combined with sulphur ; 3d, in a native state.
  In the arts lead is obtained by the following process :
 the sulphuret of lead or galena is pulverized and washed
 to separate  it from its gangue ; the gangue broken in
 pieces, washed, and roasted;  by this operation one part
 of the lead oxadizes and  combines with  the sulphuric
 acid formed by the combustion of the sulphur ; when the
 mineral is a powder (schlichs) it is mixed with clay, the
 roasting is repeated many times in order  to decompose
 the galena : the  mineral is melted in  the  furnace with
 charcoal, the lead oxidizes and is reduced; the sulphate
 of lead is changed to  a sulphuret; masses are  formed
 which must be again roasted and melted until they con-
 tain no sulphur.   When lead contains sufficient silver  to 
260
L  I  Q
 be extracted with advantage  it is  separated by cupelhi
 tion.  Lead on account of its  abundance, and the facility
 with which it is wrought, is much employed in the arts ; it
 is used for many domestic utensils, for cannon balls and
 ammunition of various kinds, for water spouts, reservoirs,
 chambers  for  the  manufacture  of sulphuric  acid, for
 printing types, dec   It is employed in  some medicinal
 preparations.
   Lead Horned. (Plomb  come.) Ancient name for the
 chloride of lead.
   Lignin.  An insipid substance without odour, insoluble
 in water, alcohol, and  weak acids.   It exists abundantly
 in plants, forming their woody fibre.
   Lilium of Paracelsus.   Lily of Paracelsus.  By this
 name was formerly designated a solution of caustic pot-
 ash in alcohol; this preparation for a longtime was greatl>
 celebrated.  It was prepared by melting in  a crucible 2
 parts of the martial regulus of antimony, 1  part of fine
 tin, and 1 part of molten copper ; the alloy which resulted
 was pulverized, mixed  with 3 times its weight of purified
 nitre ; this mixture was then gradually thrown  into a
 crucible, and heated to redness, thus detonating, calcining,
 and melting, until all the metals were oxidized ; the mix-
 ture was then  taken from  the fire, and immediately re-
 duced to powder in a heated iron mortar  ; rectified  alco-
 hol was then added while the powder was hot; after stand-
 ing some days  the liquor  appeared of an intense red; it
 was then decanted and preserved in bottles closely stop-
 ped.  Paracelsus, and  some others, thought that alcohol
 could extract  some peculiar virtue  from metals ;  they
 thus called this liquor tincture of metals ;  or lily of Para-
 celsus ; this error was exposed by Baron and  Baume,
 who  demonstrated that this metallic tincture was only a
 solution of potash in pure alcohol.
  Liquor Fuming of Boyle.  A name  formerly given
to the hydroguretted sulphuret of ammonia on account of 
L  I  T
261
 its property of diffusing white vapours in the air, as soon
 as brought into contact with this fluid.
   Liquor Fuming of Cadet.   A yellow fuming liquor,
 oily, of an insupportable odour, which Thenard considered
 as a species of oleo-arsenical acetate, containing pyro-
 acetic acid.   Cadet discovered this liquid by heating in
 close vessels equal parts of the acetate of potash and the
 deutoxide of arsenic ;  in  this operation,  besides  this
 liquid, are also obtained carbonic acid gas, carburetted hy-
 drogen, arsenuretted  hydrogen, and  another liquid  and
 volatile  product  of a brownish yellow, lighter  than  the
 first liquid, from which it also differs by containing water
 and acetic acid.
   Liquor of Flints.   (Liquor des Cailloux.)   Solution
 of silicated potash.  It is prepared by  pulverizing quartz
 or other silicious stones, mixing the powder with 3 or 4
 parts of the sub-carbonate of potash ; this mixture is by
 degrees thrown into  a crucible highly heated ;  the mi.\ -
 ture is kept in a  state  of  fusion for half an hour;  it is
 then poured out upon oiled marble, and in a concentrated
 state preserved in a closely stopped flask, or dissolved in
 water, and the solution kept from contact with the air.
   Liquor of Hoffman.   This  mineral  anodyne i<
 ethereal alcohol,  prepared by mixing equal parts of alco-
 hol and rectified sulphuric acid.
   Liquor of Lampadius.  See Carburet  of Sulphur.
   Liquor of Libavius.   See Deuto-Chloride of Tin.
  Litharge.  (From lithos a stone, and arguros silver.)
 V  name formerly given to the deutoxide of lead.
  Lithia.   See  Oxide of Lithium.
   Lithium.   The  metallic  basis of  lithia, an  oxide
discovered by M. Arwedson, a young man employed in
the laboratory  of Berzelius.   Thenard  supposes that
 ithium  may be obtained in a manner  analogous to cab
fium, and that it possesses similar properties. 
262
L  U T
   Litmus.  A beautiful blue  prepared from a white
 lichen, {Lichen rocella.)  It is an excellent test for acids
 and alkalies.   Paper dipped in an infusion of litmus, and
 called litmus paper, is much used as a test.
   Liver of Antimony.   A mixture of the oxide and sul-
 phuret of antimony.  It is obtained by burning a mixture
 of equal parts of nitre and the sulphuret of antimony.
   Liver of Sulphur.   A name given  by  the  ancient
 chemists to the alkaline sulphuret of potash.
   Lixiviation.   The application  of water  to the fixed
 residues of bodies, for the purpose of extracting the saline
 part.
   Lixivium.   A solution obtained  by lixiviation.
   Lune.  (Moon.)  A name  sometimes  given  to silver:
 thus the  nitrate of silver is called lunar caustic.
   Lune Corne'e  (Horned  Moon)  of Ludemann.   In
 some ancient works the oxide of tin is known under this
 name.
   Lupulin. Solid, very bitter, soluble in water, alcohol,
 and ether.  It  is obtained from the membranous scales of
 the pistillate flower of the hop.  It was discovered at the
 same time by Dr. Ives, Planche, Chevalier, and Payen.
   Lutes.  Substances applied in layers more or less thick
 upon the surface of bodies,  in  order to preserve them
 from the too powerful action of fire or from the air, and
 also to fill up the interstices of vessels.  A very common
 lute is of starch and the flour of flax-seed ; a soft paste is
 made with these substances, which is used for  coverino-
 around the  stoppers  fitted to retorts, matrasses,  dec ;
 another lute is  prepared by pulverizing very dry potters-
 clay, and mixing it with a suitable  quantity of  oil; this
 resists  the action  of corrosive substances, but has the
 inconvenience of being softened  by heat.
  Lute of Clay and Sand.   (Lut d'Argile et de Sable.)
Glass and stone retorts should  be  luted with a compound 
M A  D
263
of equal parts of sand and clay mixed with water and
hair.
  Lute of the White of Eggs and  Lime.   (Lut  de
Blanc d'CEuf etde Chaux.)  Is sometimes used to fill  up
cavities made by the joining of different parts of an appa-
ratus.  It  is prepared  by diluting  powdered  quicklime
with the whites  of eggs, and applying it as  soon as pre-
pared.
  Lymph.  Liquid, opaline, of a reddish tint, sometimes
yellowish.   It has a salt taste, does not redden the tinc-
ture of litmus, and greens a little the  infusion of violets.
<'hevreul has  found it to consist in 1000  parts :  Of
                926-4  of water,
                  4-2     fibrin,
                 61-0     albumen,
                  6-1     muriate of  soda,
                  1-8     carbonate of  soda,
                    •5     phosphate of lime,
a little magnesia and carbonate of lime.  Lymph is con-
tained in the lymphatic  vessels of animals.


                          M.

   Maceration.  (From  macero, to  soften by water.)
An operation which consists in the infusion of substances
in cold water, in order  to extract their  virtues ; it differs
from  digestion only as  the latter operation  admits of  the
application of heat.*  Maceration is preferable  in  all
cases where heat would be injurious; as in volatile  and
aromatic substances, dec
   Madder. A substance extensively employed in dyeing;
it is the root of the Rubia tinctorum.

  ■* AdifTerence is here made by the French chemists which is not observed by
the English, who iippear to use' the words maceration and digestion as syno-
nymous. 
264                    M A  G
    Madrepores.   A  species of coral, the  zoophyte  of
  naturalists.   They consist  of  lime and  a little mem-
  braubus animal substance.
    Magistery. (Magisterium; from magister, a master.)
  The  ancient chemists used this term for  preparations
  which they thought were made in a masterly or wonderful
  manner ; as the magistery of bismuth, sulphur, dec.
    Magistery of Bismuth.   A name formerly given  to
  the sub.nitrate of bismuth.
    Magistery of Sulphur.  Some ancient  chemists gave
  this name to the sulphur which they  precipitated by pour-
  ing acetic acid into the solution of  a soluble sulphuret.
  Sulphur  precipitated  in this manner is  almost  white,
  being in  the state  of a hydrate, and not that of an  oxide,
 as some chemists have supposed.
   Magnesium.  See Oxide of Magnesium.
   Magnesia  Black.   (Magnisie  Noire.)   A  name
 given by some chemical authors to  the  black oxide of
 manganese; it has more recently been given to pulve-
 rized vegetable charcoal.
   Magnesium.  The base of magnesia ; discovered by
 Davy.
   Magnet.  (Aimant.)   (From Magnes, the discoverer.)
 The loadstone.  It is known  by its property of attracting
 steel and  iron ; it is found in Spain, Sweden, and Siberia.
 It is an iron ore composed of  72 of metal and 28 of oxy-
 gen, or rather of  69 of the  tritoxide of iron and  31 of
 the deutoxide ; its  specific  gravity is  4-24.   A fragment
 of this metal, if placed upon a pivot, always points to the
 north and south, being  always provided with  two poles.
 For its chemical characters, see Oxide of Iron.
  Magnetism.  The  property which iron  possesses of
attracting or repelling other iron or steel according to cir-
cumstances ; that is, similar poles of  magnets repel but
opposite poles attract each other. 
MAN
265
   Malates.   Combinations of malic acid with salifiable
bases: all  these  salts expand and  decompose hy fire
giving products analogous to other vegetable substances ,
most of the malates are soluble, or become so by an excess
of acid;  they are all products of art, most of them being
prepared by directly combining malic acid with the me-
tallic oxides.   According to Braconnot, in the  malates
the oxygen of the oxides is to the acid as  1 to 9-09.
   Malleability.   (From  malleus, a hammer.)  The
property which several metals possess of being extended
■ inder the  hammer in thin plates,  or laminae,  without
.racking.  The thin plates of gold and  silver are the best
examples of malleability.
   Maltha.   A kind of mineral tallow  found  on  the
 oast of Finland.
   Manganese.  A whitish  gray metal, very hard and
brittle.  Its specific gravity is 6-85;*  it is of all metals
one of the most  difficult  to melt, fusing  but at 160° of
Wedgewood's pyrometer.  At the ordinary temperature
it  has no action upon atmospheric  air, or oxygen gas;
but if the temperature is elevated it soon oxidates.   It de-
composes water at red heat;  yet according to Thenard5
if finely pulverized manganese is put  into water at the
ordinary temperature, the metal after some time tarnishes8
and a little hydrogen is disengaged.  Hydrogen, nitro.
gen, boron, and carbon, have  no action upon this metal;
it  has not yet been ascertained what would be the effect
■sf iodine  and silicium upon it.  With much  difficulty
sulphur has  been made  to combine with it, although a
natural sulphuret exists.  At  a high temperature  it com-
bines with phosphorus,  forming a white and  brilliant
 iihosphuret, which becomes a phosphate when heated in
the air or with  oxygen.  It absorbs chlorine  rapidly,
forming a very soluble greenish chloride.  Manganese

              ' Dr. Ure states its specifie gravity at 80.
                          23 
266
MAR
 was discovered  by Scheele in 1774;  but Gahn first oh
 tained  it in the  metallic  state.   Manganese  exists
 abundantly  in nature;   it is found in the  state  of a
 phosphate  or a sulphuret,  but  most commonly as an
 oxide.  It  is extracted  from the oxide ;  for this purpose
 it is mixed with equal parts of lamp-black, (noir defumee,)
 and  made into a paste  by the addition of oil;  it is then
 formed into a ball and put into a crucible lined with pow-
 dered charcoal, the mixture also being covered with char-
 coal ; the crucible,  is then covered and exposed to the
 most intense heat for two hours ; on cooling, metallic
 masses will be found mixed with the charcoal at the bot-
 tom  of the crucible.  (Thenard.)
  Manna.   (From mano, a gift, Syrian; it being the
 food given by God to the children of Israel in the wilder-
 ness.)  Several  vegetables afford manna, but principally
 the ash, (Fraxinus ornus;) it has a sugar-like and fresh
 taste; it crystallizes in little compact needles, is very
 soluble  in  water, is little affected by the  air, except in
 being a little yellowed ; it decomposes by fire, like other
 vegetable substances;. nitric acid changes it into oxalic
 acid.  It does not furnish alcohol  by fermentation, and
 is not precipitated by the acetate  of lead.  The mannite
 exists in manna; Vogel has obtained it from the leaves
of the celery ;  Braconnot in the sugar of  the red beet;
and  M.  Guibourt in honey.   The most easy mode of ob-
taining it is to dissolve manna in boiling alcohol;  the liquor
 is filtered while hot, and on cooling the mannite is preci-
 pitated ;  it  may  be  redissolved in order to  obtain it in a
 state of greater  purity.
  Marble.   See Oxide of Calcium.
  Margarates.  Combinations of margaritic acid with
 salifiable bases.   The salts resulting from this union beat
 a great analogy to the  stearates, from which  they are
 scarcely distinguished, the principal difference being that
 the neutral margarate and the acid margarate of potash 
M E  R
267
 are much more soluble in alcohol  than  the stearates of
 the same base.   (See the works of M.  Chevreul.)
   Margarine.  A name  formerly given  to margaritic
 acid.
   Mars.   A  name  given by the ancient chemists  to
 iron.
   Massicot.   Deutoxide of Lead.
   Matter  Colouring of Leaves.  See Chlorophylle.
   Matrix.   {Gangue.)   The earthy or  stony matter
 which accompanies ores, or envelopes triem in the earth.
   Matrass.  A  glass vessel, either round  or flat at the
 bottom, with a  long neck, and usually furnished with one
 or more tubulures.
  Mellates.   {Mellitates.)  Combinations of  mellitic
acid with salifiable bases.  These salts have been but
imperfectly  studied; those of potash,  soda, and  ammo-
nia, are known  to be soluble and crystallizable ;  the first
crystallizes in long clustered prisms, and precipitates the
solution of alum; the second crystallizes in cubes, and
the last in beautiful six-sided prisms, which are at first
transparent, but become of an opaque white on exposure
 to the air.
  Melting.    Synonymous  with  fusing.   Change  of
 state effected by caloric.
  Menstruum.  A word synonymous with solvent.  The
 principal menstrua made use  of in pharmacy, or the pre-
paration of  medicines, are vinous spirits, oils, acids, and
 alkaline liquors.
  Mercury.   (Mercure.)  Is a metal of a bluish white
 colour, liquid at the ordinary temperature ; its density is
 13-568.  It boils at 642°, is  reduced to vapour, and con-
 denses  in a receiver  fitted to the neck of the retort.  It
 volatilizes a little, even at the ordinary temperature, as
has  been demonstrated by Faraday.   By exposing for
 some time over a vessel of mercury a leaf of gold, it will
be found sensibly whitened.   Exposed to a cold of from 
±68
VI  E R
—39° to —40°, mercury solidifies and crystallizes in octo
edrons.  In order to produce this degree of cold, 2 parts
of chloride  of sodium, (common salt,) with one  part of
snow, are mixed ; and into a vessel containing this mix-
ture a matrass containing mercury is introduced ; this in
a few minutes will begin  to solidify.  Thus congealed, it
is malleable; if applied  to the skin  in  this state, it will
produce a sensation no less painful than that of red hot
iron ;  whitening the point touched, and  producing disor-
ganization, if the painful contact be prolonged.  This
metal at the ordinary  temperature has no  action upon
atmospheric air, or oxygen gas ;  but at the temperature
of boiling heat, it gradually becomes a  red oxide ;  this
the  ancient chemists called precipitate per se.   Mercury
does not combine with hydrogen, boron, carbon, or nitro-
gen ; its union with phosphorus is still  doubtful; but  it
easily combines with chlorine, sulphur, selenium, iodine.
and many of the metals ; the alloys formed by it with the
latter are called amalgams.
  The discovery  of mercury :s of the highest antiquity :
this metal was of all others the most tortured by the al-
chemists ;  they imagined  it was liquid silver, and b\
solidifying it would form that metal.   They thought, thai
in order to bring mercury to a solid state, it must be
heated for a long  time.   Boerhaave, who laboured upon
this metal with a  patience almost unparalleled, held  it  in
digestion for twelve successive years,  but  without  any
visible alteration.    He thus demonstrated the absurdity of
their attempts to bring it to silver by that method.  The
alchemists in their vain attempts to make of mercuiy
something  for which nature had not  designed it, disco-
vered many medicines which are of great importance  in
the materia  medica. The uses of mercury  are very nu-
merous in the arts as well as in medicine.   It  is  usually
extracted by heating the sulphuret mixed with lime in a
galley  furnace ; the lime unites with  the sulphur of the 
MET
269
sulphuret; the mercury volatilizes, and condenses in the
receiver.
   Mercurius Dulcis.  (Mercure Doux.)  Calomel.  See
the Proto-Cloride of Mercury.
   Mercury  Fulminating.  The ammoniuret of mer-
cury.
   Mercury  Soluble  of Hahnemann.  See  Nitrate  of
Mercury.
   Merccrification.  An  ancient operation of alchemy
by which the professors of this science pretended to re-
duce all the metals into one metallic liquor; or according
to them, to draw from  metals their mercurial  principle.
\mong the books of some ancient writers may be found
many processes for this purpose.  One of the alche-
mists, Teichmeyer,  even  asserted, that  if  iron filings
were for a year exposed to  the  atmosphere, afterwards
well triturated in a  mortar, left to stand another year  in
the air,  and then submitted to distillation in a retort, they
would furnish some  mercury ; this error might have been
caused by the circumstance of  some alchemists happen-
ing to distil as iron,  metallic oxides, which,  unknown  to
them, contained a little mercury.
   Metals.   (Melaux.)  They  are  elementary bodies
almost wholly opaque, very brilliant in masses, and  pos-
sessing this  property  even when pulverized; they are
susceptible of a polish  more or  less bright according  to
their nature.   They are good conductors of caloric and
electricity; are capable of combining with oxygen and
of forming oxides which have a metallic appearance, and
which by uniting to acids saturate them  and form  salts.
Of all substances in nature none have so  much attracted
the attention  of chemists as the metals.   To how manj
experiments  did the alchemists not  subject them, that
they might discover the grand secret,  (grand eeuvre,) the
philosopher's stone ?  They believed that by some  hid-
den process even the basest metal might be converted
                        23* 
270
M E  T
into gold and silver;  they laboured with  such zeal  and
perseverance that many, animated  with indefatigable
courage, sacrificed their  fortunes  and lives to this delu-
sion.  They  pretended even to have discovered  immor-
tality, when  Paracelsus, the . leader of  this  sect,  who
boasted  the  possession of the secret, died at the age of
48 years.  From  so many labours we have derived some
advantages;  metallurgic chemistry  owes many of its
discoveries to the  alchemists.   Yet they  were far from
knowing all the metals, for in the  fifteenth century were
known only gold,  silver, iron,  copper, lead, mercury, and
tin, and  now we reckon 41.
  Among the various classifications of metals made by
chemists, that of Thenard is the most scientific.

     TABLE  OF  THE DISCOVERY OF  METALS.
Names of Metals.          Discoverers.      Period of their discovery
Gold,
Iron,
Silver,
Copper,   > Known from the earliest periods.
Mercury,
Lead,
Tin,
Zinc,   .  Discovered by Bombast Parulo, in 1541
Bismuth,   Described by Agricola, in        1520
Antimony, Described by Basil Valentine, 15th century.
^TS™ic'  I Brandt,     .     ...    1733
Cobalt,    S
Platina,   . Wood, an assayer at Jamaica, .  1741
Nickel,   . Cronstedt,  ....     1751
Manganese, Gahn, Scheele,   .    .    .     1774
Tungsten,  D'Elhuyart,      .    .          1781
Tellurium, Muller,    .    .    .    .     1782
Molybde- > Suggested by Scheele and Berg- )  17fto
   num,   $    man, discovered by Hielm.   S 
.MET
271
Names of Metals.
Titanium,   Gregor,
Uranium,   Klaproth,
Chromium,  Vauquelin,
Columbium, Hatchett,
Palladium,
Discoverers.      Period of their discovery.
                      1787
                      1789
                      1797
                      1802
Rhodium,
Iridium,
Wollaston,
Descotils, Vauquelin, Fourcroy,
  Smit.ison, Tennant,
Tennant,
Berzelius and Hisinger,
1803
1803
 Davy,      .     .

Hermann and Stromeyer,
Arfwedson,    ,  .
> Berzelius,
1807

1818
1818
1824
1828

1828
Osmium,   Tennant,        .     .     .     1803
Cerium,   Berzelius and Hisinarer,     .     1804
Potassium,
Sodium,
Barium,
Strontium,
Cadmium,
Lithium,
Silicium,*
Zirconium,
Pluranium, Osann,
Aluminum, }
Glucinum, v Wohler,
Yttrium,   j                              }
   Thenard divides the metals into six sections, founded
upon their affinity more or less great for oxygen.  In his
first section  he places  those which  have not been re-
duced,  and which are admitted only by analogy.   The\
are seven :
   1st Section.  Magnesium,        Thorinium,
               Glucinum,         Zirconium,
               Yttrium,           Silicium.
               Aluminum,
   In the second  section he  places those which absorb
oxygen gas at the highest temperature, and which pos-
sess the property of suddenly decomposing water at the
 * It seems doubtful whether this substance should rank among the metal*, ii
being deficient in metallic lustre, and not a conducter of electricity. 
272
MET.
ordinary temperature by uniting with its oxygen and di>
engaging  the  hydrogen  with  a lively  effervescence.
These metals are the six following :
  2r7 Section.   Calcium,           Lithium,
               Strontium,          Sodium,
               Barium,            Potassium.
  In the third section he places the metals which absorb
oxygen  at a very high temperature, but which do not de-
compose but at a red heat, these are the five following :
  3d Section.   Magnesia,         Tin,
               Zinc,             Cadmium.
               Iron,
  The fourth section is composed of all the metals which
like the preceding absorb oxygen at  a very  high  tem-
perature, but which do not decompose water,  even  with
the aid  of heat.  This division  contains the fifteen fol
lowing :
\th Section. ^  /-Arsenic,           Cerium,
          3  \Molybdenum,      Cobalt,
          * -sChromium,        Titanium,
           y  /Tungsten,          Bismuth,
            H  ^Columbium.        Copper,
               Antimony,         Tellurium,
               Uranium,          Nickel,
               Lead.
  Thenard also forms of  the fourth a sub-section, in
which he places the first five, which are acidifiable.
  The fifth section is formed of such metals  as absorb
<>xygen  gas  but at a certain heat, which cannot decom-
pose water and whose oxides are  reduced but at a high
temperature ; there are two metals of this kind :
      5th Section.  Mercury,       Osmium.
  The sixth and last section comprises the  metals which
cannot absorb  oxygen gas and decompose water at an\
temperature,  and  whose oxides are reduced but at  re*-i
heat.  There are six metals in this section : 
M E  T
273
  dth Section.   Silver,              Platina,
                Palladium,          Gold,
                Rhodium,           Iridium.
  The physical characters of the metals are, lustre, hard-
ness, opacity, colour, density, ductility, malleability, tenacity,
elasticity, sonorousness, specific gravity, taste., odour, and
structure.  Lustre  (eclat)  is the property which  metals
possess, even when pulverized, of reflecting a  great
quantity of light;  such as possess this property in a high
degree, are gold, silver, iron, platina, palladium, tin, &c
  Metals vary much as to their hardness, some possess-
ing this quality so as to cut most substances, others being
so soft as to  be divided with the finger nail.   Thomson
has stated the hardest metals to be, tungsten, palladium,
manganese,  iron, nickel,  platina,   copper,  silver,  gold,
bismuth, cobalt, tin, lead, &c. ; from this statement one
might conclude that the metals are hard in proportion  as
they are difficult to fuse.
  The metals are opaque,  but this  opacity does not ap-
pear to be absolute, for a leaf of gold transmits some lu-
minous rays, and as next to platina this is the most dense
metal, it would appear that no metal is wholly opaque.
  The colour of metals is very different,  although there
are but two  or three principal  colours.   The  following
table exhibits their various shades :
COLOURS OF METALS.
          White.
Silver (Argent)   .
Tin (Etain)   .   .
Platina (Platine) .
Aluminum  .   .   .
Palladium  .   .   .
Nickel   ....
Mercury  (Mercure)
Iridium   ....
Tellurium {Tellure)
Cadmium  .   .   ,
Silver white
    do.
    do.
    do.
Pale white.
White, slightly azure
    do.
    do.
Silver white 
74                    MET

   Antimony (Antimoine) .  The same with a bluish refiec
   Cobalt   ......  Grayish white.         [tion
   Potassium >             ,IT. .,. , -
   c  ,.      >   ....  Whitish gray.
   Sodium   S

    .     ■     >  .   .  .   .  Gray of polished steel.
   Arsenic    S
   Rhodium
                  .  .   .   .     do.
    Cerium   S
    Lead (Plomb)  .... Slaty white.
    Zinc.......     do.
    Bismuth......Yellowish white.
    Iron (Fer).....Gray.
    Molybdenum (Molybdine) )          ,
    Uranium  (Urane)        S               '
    Osmium......Bluish black.
    Gold (Or)  .  .  .   .  '. Yellow.
    Copper (Cuivre) .   .   . Reddish.
    Titanium {Titane)   .   .     do.
    Glucinum  .  .  .   . '  . Deep gray.
    Yttrium......     do.

  Density, or specific gravity, is a property which wa.-
long believed essential  to  metal.   Before the discovery
of potassium, it was  believed that the metals  were the
most dense, and of course  the most heavy of all bodies in
nature ; platina is indeed  more than 22  times as heav)
as water, but  potassium is lighter than water,  since it
swims upon this liquid.  The property of density has now
ceased to be characteristic.   The following table from
Thenard exhibits the relative  density of metals :
TABLE OF THE SPECIFIC GRAVITY OF THE METALS.
    Metals.      Specific Gravity.  Authorities.
   Platina  .   .  .  20-98     Brisson.
   Gold .  .
   Tungsten
   Mercury .
Palladium
Lead  .   .
Silver .
Bismuth  .
19257   Brisson.
17-6     D'Ethayart.
13-568   Brisson.
118     Wollaston.
11352 )
10-4743 > Brisson
 9-822 > 
M E  T
Metals. Specific gravity.		Authorities.
Uranium . .	. '9.	Bucholz.
Cobalt . .	. 8-5384	Hauy.
Copper . .	8-895	Hatchett.
Cadmium	8-604	Stromeyer.
Arsenic . .	8-308	Bergmann.
Mickel . .	. 8-279	Richter.
Iron . . .	7-788	Brisson.
Molybdenum	7-400	Hielm.
Tin . . .	7-291	Brisson.
Zinc . . .	6-861	Brisson.
Manganese .	. 6-850	Bergmann.
Antimony	6-7021	Brisson.
Tellurium	6115	Klaproth.
Titanium	5-300	Wollaston.
Sodium .	0-972 ) 0-865 \	Davy, Gay-Lussac, and
Potassium		Thenard.
Cerium . .	. 4-489	Hisinger and Berzelius.
  By ductility is meant the property which many metals
possess of being  drawn out into fine wire.   When they
can be extended  under the hammer, or spread out  into
thin leaves, this property is called malleability ; it is very
different from ductility,  for those metals which can be
best drawn into wire, are not always those which can be
made into leaves, as iron, for example.
   The greater weight a metal drawn into wire is able to
sustain,  the greater is its tenacity.   Such as possess this
property in the greatest degree  are iron, copper, platina,
silver, gold, tin, zinc, &c.
   The elasticity and sonorousness of metals are always in
proportion to their hardness; it is for this reason, that in
order to increase these properties, metals are often com-
bined with such  substances as  will render them harder.
For example, iron combined with charcoal is harder and
more elastic than iron alone ; tin alloyed with copper is
harder  and more sonorous than either of these metal?
before they are combined. 
276
M E  T
   Taste and odour are properties inherent m some mt
 tals.   Copper has a very disagreeable taste and odour:
 iron, tin, and lead have peculiar tastes ; gold and  silver,
 upon being rubbed, are insipid and inodorous.
   By structure is understood the tissue or arrangement of
 the integrant  parts of a metal;  sometimes  it is fibrous.
 sometimes granular, &c.
   The chemical properties of  the metals are not less in.
 teresting than their  physical properties.   1st.  Action of
fire; exposed to the action of fire, metals fuse at very dif-
 ferent  temperatures, some fusing at less  than  red iteat.
 others but at the highest degree of heat, and some are al-
 most infusible at any temperature.   When a metal is in
 a state of fusion, if the crust formed upon the surface isr
 pierced and the liquid part decanted, it is obtained crys-
 tallized.  When metals are submitted to a heat greater
 than is necessary for its fusion, a  small number  vola-
 tilize.
   M. Children,  who has  made a long series of experi-
 ments  upon the action of electricity with respect to  me-
 tals, has demonstrated that its action has a great resem
 blance to that of caloric, only that it acts in a more ener-
 getic manner ; causing the fusion of those metals  which
 have resisted  the  most powerful application of caloric,
 burning with facility the-wire  of platina, gold, iron, &c.
   Oxygen also  produces  with metals important pheno-
 mena, some absorbing it at the ordinary temperature,
 others but at the most elevated temperature ; sometimes
 disengaging caloric and light,  though usually this pheno-
 menon does not accompany the combination of oxygen
 with the metals.   Some metals do not combine with oxy-
 gen at  any  temperature.   Most simple substances, not
 metallic, form with oxygen peculiar compounds.
   The immortal Lavoisier  first proved, that when the
 acids unite  with metals, they are burnt,  or what  is the 
M I L
277
same thing, transformed to oxides.  Tt follows then that
whenever an acid is brought in contact with a metal, the
latter burns at the expense of the oxygen of the acid, or
by absorbing the oxygen of the water and disengaging
hydrogen.
  Milk.   {Lait.)  An opaque liquor, white,  opaline,
heavier than water, of a sweet and  sugared taste.  When
this liquor is evaporated, it forms a pellicle  which is soon
replaced by another, if the first is removed.   If submitted
to distillation, it furnishes a liquid which contains a certain
quantity of milk.   Milk left to itself at the ordinary tem-
perature, separates into serum or  whey, caseous matter,
and cream.   The cream, which contains much butter, on
account of its specific levity, rises to the surface ;  it is
yellowish  white, of a  sweet and  agreeable taste.   The
serum  or whey, is a transparent, greenish  yellow liquid,
composed of much water, sugar, milk, and many salts ; it
also contains acids, as it reddens litmus.   According to
Gay-Lussac, milk may be preserved many months  by
heating it  a  little every day.   Milk mixes  with water in
all proportions ; all the strong acids, unite with its caseum.
Alcohol coagulates milk, but  acts with it  in a manner
different from the acids, having no action upon its caseous
matter; it acts upon it by uniting  with the water of the
milk.  The acetate of lead, and perhaps some other salts,
coagulate milk ; potash, soda, and ammonia redissolve the
coagulum formed by acids.  According to  Fourcroy and
Vauquelin, cow's milk is composed of a great quantity of
water, acetic acid, sugar of milk, a substance analogous
to gluten, muriate of potash, fluate of potash, and muriate
of soda.
  Berzelius has  made the following  analysis  of  cow's
milk:   In 1000 parts, from which the  cream had  been
taken off, he found
                         24 
278
M  O L
  Water,       -        -     -       .        928-75
  Some traces of butter and caseum     .      28-00
  Sugar of milk,.....35-00
  Muriate of potash,      .    .     .     .     1-70
  Phosphate of potash,  ....       0-25
  Lactic acid, acetate of potash with one atom
of acetate of iron,      .....   6-00
  Earthy phosphate,       ....     0-50
  Mine de Plomb Noire.   {Black Lead ore.)  A name
formerly given to  the per-carburet of iron.
  Mine de Plomb Rouge.  (Minium, Latin.)  Red lead.
See Tritoxide of Lead.
  Miraculum Chimicum.   The ancient chemists gave
this name to a solid compound, which  they obtained by
mixing equal parts of the liquid sub-carbonate of potash
and the deliquesced chloride of lime.  By their mixtures,
hard and stony matter was instantly formed.   It is evident
that here was a  double decomposition; the product of
which was  a sub-carbonate of lime and chloride  of  po-
tassium.
  Mofette Atmosphe'ri'que. A name sometimes given
to azotic (nitrogen) gas.
  Molecules.  In chemistry, by the term molecules, is
understood very minute  homogeneous particles, invisible
on account of their great tenuity, which by their union
form substances.   When the body is elementary, all the
molecules are the same ;*they are then called integrant
molecules, atoms,  or particles ; thus in a piece of sulphur,
all the molecules  are integrant molecules,  a compound
body.  For example: an alloy of lead and tin is  formed
of an assemblage of many integrant molecules ;  but each
of these substances would be composed of two others of
different kinds, viz: one molecule of lead and one of tin ;
these  last in  this case, are called  constituent molecules.
(See Atoms, and Attraction.) 
M O  L
279
   Molybdates.   Combinations of  molybdic acid with
 bases; all the salts resulting from this  combination, are
 decomposable by charcoal,  aided  by heat; sometimes
 the  molybdic  acid is brought to the state  of an oxide ;
 sometimes the acid and the  oxide are  reduced ; this  is
 particularly the case with the molybdates of the last four
 sections.*  The neutral molybdates  of potash,  soda, and
 ammonia are very soluble ;  those of lime, strontian,  and
 alumine  are  scarcely so ; those of  barytes, and of the
 last four sections, are always insoluble when the oxide of
 a molybdate can form a soluble salt with nitric and hydro-
 chloric acids  ; sulphuric acid decomposes all the molyb-
 dates, and  precipitates the  molybdic  acid.   Only  one
 molybdate is yet found in nature, viz: that of lead.  It  is
 crystallized in tables, is of a very pale yellow, and its
 specific gravity is 5-480.   It  is found in Iceland, Siberia,
 Austria,  Sweden, Spain,  and Mexico.   All the soluble
 molybdates are prepared directly ; all the others are pre-
 pared by double decompositions.   These salts were dis-
 covered by Scheele.  In the molybdates the quantity of
 oxygen of the oxide, is to the oxygen of the  acid as  1
 to 3.
   Molybdate of Ammonia.   Uncrystallizable,. styptic,
 of a caustic taste ; submitted to the  action of fire, it first
 disengages  ammonia ;  if the heat is increased, the hy-
 drogen of the ammonia is burnt by the oxygen of the mo-
lybdic acid,  and water and nitrogen are disengaged ; the
residue is the  oxide of molybdenum.  This  salt is  ob-
tained by combining  directly molybdic acid with  am-
inonia.
   Molybdate of Potash.   Crystallizes in  rhomboidal
shining lamina; it is of a  metallic lustre, more soluble
with hot than cold water ; not decomposable by fire.  It
is obtained by saturating a solution of potash by molybdic
acid, as in the molybdate of ammonia.
      '* See Thenard's arrangement of metals, in the article Metals. 
280                    M O  R

  Molybdate of Soda.   Very soluble;  not  decompo-
sable by fire, styptic, unalterable by the  air.   It is ob-
tained in a manner  similar to  the molybdate  of potash,
and crystallizes more easily.
  Molybdenum.   (Molybdene.)  From the Greek  mo-
lubdos, lead.)  A metal whose physical properties are not
yet well known, on  account of the difficulty of fusing it.
It has been obtained only in  little  agglutinated grains.
Hielm, who first obtained it, had described  it as yellowish
on the surface, and greenish  in  the interior.  Clarke,
who  obtained it  in dross, by the aid of his gas blow-
pipe, states that in this state it is little brilliant; its  spe-
cific  gravity, according to Hielm, is 7-400, and according
to  Bucholy,  8-611.  This metal was long confounded
with  the per-carburet of iron.  Cronstedt first gave it the
name of molybdenum; but it was not  until  1782, that
Hielm obtained  the metal.  Pelletier and Heyer after-
wards studied its properties.  This metal resists the most
intense heat.  It  has no action upon oxygen  at the or-
dinary temperature  ; but at red heat  it transforms it  into
molybdic acid, which sublimes.  It  has been combined
only  with chlorine,  sulphur, and phosphorus.   Molybde.
num does not exist pure in a native state ;  it has yet been
found only in the state of a sulphuret  of molybdenum,
and the molybdate of lead ; the former is  common in the
Alps, the other in Austria.  In order to extract the metal,
the .sulphuret is boiled in nitric acid ;  to acidify the metal,
a  paste is formed  with molybdic acid, lamp-black, and
oil;  this is introduced into a crucible lined with charcoal,
(cruset brasque) and the  operation then proceeds as for
the  extraction  of  manganese* raising  the heat  to its
greatest height towards the close of the process.
   Mordant.  In dyeing, the substance  combined with
the  vegetable or animal  fibre, in order to fix the dye.
stuff. 
M 0 R
281
   Morphia.   (Morphine.)   It is white, bitter, crystallizes
 in prismatic acicular crystals, with four oblique sides.  It
 is insoluble in cold water, little soluble in boiling water,
 but soluble in hot alcohol;  submitted to the action of fire,
 it fuses in a radiated mass ;  heated more strongly it gives
 azoted products.   Concentrated sulphuric acid poured
 upon morphia, chars it; nitric acid gives it the colour of
 blood; weak  acids combine with it,  and form  neutral
 salts.   Its  existence  was suggested  by  M. Seguin,  in
 1804,  and it was discovered  by M. Sertuerner, a phar-
 macian, in 1808.  It has been found only  in opium, where
 it exists  combined with meconic acid.   M. Sertuerner
 obtained it by precipitating the aqueous solution of opium
 by  ammonia.   M. Robiquet has  described a process
which  is thought preferable ;  it consists in boiling for a
quarter of" an hour, a concentrated infusion of opium with
a small quantity of pure magnesia, collecting upon a filter,
and washing with cold water and weak alcohol the grayish
precipitate which  is formed ; this precipitate being acid,
is digested for some minutes with boiling rectified alcohol;
the boiling liquor is then  filtered.   Alcohol,  aided  by
heat,  dissolves all the morphia, but does  not  affect the
meconate of magnesia ;  on cooling, the morphia crystal-
 lizes.   It is purified by reiterated solutions, and the better
 if a little animal charcoal is added to the  alcohol.  Pelle-
tier vainly endeavoured to  extract morphia  from the
poppy* indiginous to France, the solance, and some other
plants.
  This substance  in a state of purity has very little action
upon the animal economy; this is not the case when this
alkali is combined with an acid; it has then all the poi-
sonous qualities of opium.   The name of morphia, (from
Morpheus, the god of sleep) has been  given on account
of its somniferous properties;  it is composed of

  * Opium is extracted  from the Papaver sommiferum; it is exported from
Turkey, Egypt, and the East Indies:
                          9A* 
 2*2                   M U S

                  Carbon,    72-02
                  Azote,      5-53
                  Hydrogen,  7-61
                  Oxygen,   14*84
  Mort aux Mouches.  (Flies' Bane.)  A name given to
powdered  metallic arsenic, on account of its properly
when diluted in water, of destroying  flies who taste the
liquor.
  Mort aux Rats.   (Rats' Bane.)  The deutoxide of
arsenic.
  Mortar.   The mortars used in chemistry for pulver-
izing substances, are of iron, brass, copper, glass, por-
celain, marble, stone, &c.
  Mucates.  Combinations of mucic acid with salifiable
bases.   All the salts which result, are decomposable by
fire and by strong  acids.  The  mucates of ammonia,
potash, and  soda, are alone soluble.   Lime water  and
barytes  decompose them, forming mucates of lime and
barytes, which are insoluble.  The soluble mucates are
obtained directly; the others by double decomposition.
According to Berzelius,  in the mucates the quantity of.
the  oxygen of the oxide, is to the quantity of the acid as
1 to 13-185.
  Mucilage.  An aqueous solution of gum.
  Muriates.  Before the discovery  of chlorine, hydro-
chloric acid, which was thought to be acidified by oxygen,
bore the name of muriatic acid, and  all the compounds
which  it forms  by combining with  bases were called
muriates.  (See  Chlorides and Hydro-chlorates.)
  Muriates Oxygenated and Sub-Oxygenated.  See
Chlorates and Chlorides.
  Mushrooms.  {Champignons.)    Many chemists have
investigated the properties of these vegetable substances.
The first experiments were made by Bouillon-Lagrange;
his  analyses were mostly confined to the Boletus igniarius 
M Y R
283
and laricis.   Braconnot states that the Boletus juglandis
is in 1260 parts, composed as follows :
	1118-30
	95-68
Insoluble animal matter, ....	18-00
Animal matter soluble in alcohol, -	12-00
	7-20
	6-00
	1-20
	112
Sugar,.........	0-50
Some traces of phosphate of potash.	
Vauquelin states that the Agaricus campestris is composed
of water, fibrous  matter, albumen, sugar, oil, adipocere,
a  substance which  he calls  ozmazome} insoluble ani-
malized matter, and  acetate of potash.
  Mushroom Philosophic. (Champignon Philosophique.)
A name formerly given to  a spongy charcoal obtained as
a residue in the burning of certain oils by a mixture of
nitric and sulphuric acid.
   Myricin.  (Mericine.)  A name given to the substance
which remains after treating with alcohol the wax of bees
or that of the myrica and ceroxylon.  It is solid, fuses at
a temperature between 95° and 100° ; its specific gravity
is  equal to water ; it is very little soluble in boiling ether,
but dissolves entirely in the volatile oils.
  Mvrr.ii.   (From  a  Hebrew word, Myrrha.)  A gum-
resin obtained from a tree which grows on the eastern
coast of Arabia Felix.   It  is of a turbid brick-red colour,
solid and heavy, of a peculiar smell and a bitter taste.  I*
is soluble in boiling  water. 
284
N A  R
                         N.

  Naphtha.   See Bitumen.
  Naphthaline.   A white substance with the lustre of
silver, soft to the touch, and odorous.   It fuses at 180°,
and crystallizes in cooling.  It is prepared  by distillation
from  coal-tar.   Naphthaline is heavier than water, dis-
solves very sparingly in hot water, but is soluble in ether
and alcohol.   Dr. Thomson terms it a sesqui-carburet of
hydrogen.
  Narcotine.  A vegetable  substance, white, insipid,
inodorous; it crystallizes in  rhomboidal  prisms, often
clustered.  By distillation it affords the same products as
animal substances; boiling water dissolves of it but ?i7,
cold alcohol Ti^, and boiling  alcohol ^\ ;  ether and the
volatile  oils dissolve it with heat; cold acids dissolve it;
the alkalies precipitate it from  the acid solutions.  It has,
from  its discoverers, been  called salt of Desrosne, (sel
de Desrosne.)  It is often called salt of opium.  Its action
upon  the animal economy is not very energetic unless it
contains morphine, which is sometimes the case.   Nar-
cotine is obtained by treating  with  ether  the opium of
commerce until its strength is exhausted.   This ether is
at first  of a yellow colour ; it remains for some time tur-
bid, at  length  deposites a  powder  which by distillation
yields a large quantity of ammonia;  when the powder
ceases to be  deposited, the  ether is  decanted  and evapo-
rated ;  crystals are formed whieh are impregnated with a
viscous oil containing little masses of caoutchouc, (indian
rubber,) which can be mechanically separated.  Tlie oily
liquid is decanted to separate the  crystals, and treated
with boiling alcohol; on  cooling, the narcotine is depo-
sited  in crystals;  it is redissolved  in  the  same  liquid.
again crystallized, and obtained pure. 
N I C
285
  Natron.  (So called from  Natron, a  lake in Judea
where it was  produced.)  A natural carbonate of soda,
which is produced abundantly in some lakes by the con-
tact of the  chloride  of sodium (common salt) with chalk
or some variety of carbonate of lime.
  Neutral.  A saline compound possessing neither the
characters of acids nor alkaline salts; such are Epsom
salts, nitre, and  all  the compounds  of the alkalies with
the acids.
  Neutralization.   When acid and alkaline matters
are combined in such proportion that the  compound does
not change the colour of violets or litmus, they are said to
be neutralized.
  Nickel.  (Nike!.)  A white  metal, very malleable ;
its specific gravity  is 8-279; it appears to possess mag-
netical  attraction, a property  which belongs, with this
exception,  only to  iron  and cobalt; nickel when com-
bined with other substances loses  this property,  while
iron loses it but  in passing to the third degree of oxida-
tion.  It is extremely difficult to fuse, though highly vola-
tile ;  if heated in contact with the  air or oxygen at red
heat, it-absorbs the  latter gas, and changes it to a green
oxide.  It forms combinations with most of the simple
bodies ; is dissolved in nitric acid. Its solution gives with
the alkalies a green precipitate.
  Nickel is found  in nature in the  state of an oxide, an
arseniate,  but most abundantly as a sulphuret of nickel
united with arsenic, a small quantity of iron, copper, and
cobalt; this compound is called by the Germans kupfed-
nickel;  from this, nickel  is usually extracted.   The pro-
cess  for obtaining  it is  complicated : it is necessary at
first to  wash the ore, in  order to expel the arsenic and a
small quantity of sulphur ; it is then  subjected to powerful
heat in contact with saltpetre (nitrate of potash) ;  this
oxidates the metals, and forms, with the remaining arsenic
nnd  sulphur, the arseniate and  sulphate of potash; the 
286
N I C
 whole is, put into a large quantity of water, in order to
 carry off the excess of potash  and soluble salts; a mix-
 ture of the oxide is the residue ; this is treated with hydro-
 chloric acid ;  the excess of acid is driven off by evapora-
 tion ; the  chlorides are dissolved in water,  and that of
 copper is precipitated by a current of sulphuretted hydro-
 gen.  The iron  and the greater part of the  cobalt are
 precipitated  by ammonia;  the solutions of  nickel  and
 a little of cobalt are treated with potash,  which combines
 with the  hydro-chloric  acid,  and precipitates  the  two
 oxides.  These are carefully  washed, and by the aid of
 heat treated with a concentrated  solution of oxalic acid,
 which forms two insoluble oxalates ; these are washed,
 aud slightly treated with liquid ammonia, which dissolves
 them.  The liquor is exposed to the air, and decanted
 when nearly free from the ammoniacal odour;  the depo-
 site is entirely composed of the double oxalate of nickel
 and ammonia ; this is washed, and on being exposed to an
 elevated temperature, pure nickel in a metallic  state is
 obtained.
  Nicotin.  (Nicotine.)   A peculiar  principle obtained
 by Vauquelin from tobacco.  It is colourless, andhas the
 singular  taste  and smell of the plant.   It dissolves both
 in water  and alcohol;  it is volatile and  poisonous.   To
 obtain it, evaporate the expressed juice of tobacco to one
 fourth its  bulk; when cold, strain it through  fine linen ;
 then evaporate it nearly to dryness; dissolve  this again
 in alcohol, and again reduce it to a dry state.  Dissolve
 the residue in water, saturate the  acid which  it contains
 with a weak solution of  potash, introduce the  whole into
 a retort, and  distil  to dryness;  redissolve,   and  again
dissolve three or  four times successively.  The nicotin
 will thus  pass  into the receiver dissolved in water, from
 which solution  it may be obtained by very gradual evapo-
 ration. 
N I T
28;
  Nihil Album.    White nothing.   A name formerly
given to the oxide of zinc.   See this word.
  Nitrates.   (From  nitrum,  nitre.)   Salts formed by
the union  of  nitric  acid with salifiable  bases; as the
nitrates of potassa, soda, silver, &c. Exposed to the action
of fire, all the nitrates  are decomposed, but at different
degrees of heat; some give off at once oxide of nitrogen
or nitrous acid.  When the metal has much affinity for
oxygen, and is not at the highest  degree  of oxidation, it
absorbs a  portion of  this gas,  becoming more  highly
oxidated ; thus by heating the  proto-nitrate of mercury,
the deutoxide  is obtained; in other cases, the tempera.
ture being  high, and the metal having little  affinity for
oxygen, it is reduced.
  Those metals which  have the least affinity for oxygen,
such as gold, palladium, &c, form nitrates which, exposed
to a temperature a little elevated, disengage  thgir acid.
As nitric acid cannot exist without water, the nitrates of
course  contain  a  small quantitv.  The  nitrates are de-
composed by most of the non-metallic combustible bodies;
sulphur in decomposing them often forms a sulphate when
the oxide has as much affinity for sulphuric  acid as for
the alkalies; otherwise it forms a sulphuret; this is most
commonly the  case.   With  the  nitrates whose  metals
have not yet been  obtained, sulphur  can  form only sul-
phurous acid  and  an  oxide.  The nitrate of magnesia
forms an  exception.
   When the  nitrates  are heated with  charcoal, a car-
bonate will be the result; if the oxide has  as much affinity
for carbonic acid as for potash, soda, &c, the metal will
be reduced; if the  oxide has little  affinity for oxygen,
either an oxide and carbonic acid will  be obtained or an
oxide of carbon, according to the temperature, and quan-
tity of charcoal. Most of the nitrates are soluble in water;
such  as   are  not, become so  by long contact  with
ibis liquid; there are of these two classes : those whose 
288                    NIT
bases are in excess precipitate  in the  form of a sub-
nitrate the others with an excess of acid dissolve.
  A great number of acids, as sulphuric, phosphoric, ar-
senic, &c, decompose the nitrates; their action is more
lively in proportion as the temperature is elevated.   The
property which sulphuric acid possesses of decomposing
the nitrate of potash, (saltpetre,) is the foundation of the
art of preparing nitric acid.
   When into a solution  of a metallic nitrate based nei-
ther upon potash, soda, nor lithia, is poured a solution of
a sub-carbonate, a sub-phosphate, sulphate, &c, based
upon potash or soda, the  result is, a decomposition of the
two salts, forming a soluble nitrate, and an insoluble sub-
carbonate, sub-phosphate, &c  It is  only when the ni-
trate is very acid that decomposition takes place ;  since,
in order that the borate  or phosphate, &c. found, should
be acid and soluble, the excess of acid must be saturated
by potasli  or soda.   (M.  Thenard,  Traite de  Chimie,
tome III.)
   One nitrate exists in nature in large quantities, that of
potash or saltpetre ; but it is  always disseminated, and
never found in large masses.   The nitrates of magnesia
and lime are found in nature ; also  the nitrate of soda
lately discovered in Peru.  The nitrates appear to form
themselves, when a salifiable base sufficiently energetic
is in contact with decomposing  animal substances.  In
this way the nitrates of lime, magnesia, and  potash, are
formed under our eves ; but we  are ignorant of the pro-
cess which nature  carries on in the formation of the
great quantities of the nitrate of potash, which cover the
surface of the ground in  many  southern countries.  In
the neutral nitrates, the quantity of the oxygen  of the
oxide is to the quantity  of the oxygen of the acid in the
proportion of 1 to 5; but the sub-nitrates are an excep-
tion to this law of composition.  The quantity of the base
which  they contain is extremely variable, sometimes 
N I T
289
being  eight times  greater  than that of the  neutral ni-
trates.
   Nitrate of Alumine.   (Nitrate d'Alumine.)  A deli-
quescent salt, very styptic, and soluble; it reddens the
tincture of litmus, and is decomposed at a low tempera-
ture.   Alumine in jelly is  precipitated  from its solution
by the careful addition of an  alkali.  It is obtained di-
rectly by uniting nitric acid to a jelly of alumine.   It  is
without use.
   Nitrate  of  Ammonia.    (Nitrate  d'Ammoniaque.)
Crystallizes  ordinarily in six-sided prisms,  joined and
grouped longitudinally.   It is  colourless, of a pungent
taste, attracting in a slight degree moisture from the atmo-
sphere.  Cold water dissolves  a part of its weight;  if
exposed to the action of moderate heat, it soon melts in
its water of  crystallization; by elevating the tempera-
ture, it is  decomposed ; this  decomposition  will  be at-
tended with an elimination of  caloric and light, if the ni-
trate is thrown upon burning coals ; from thence its name
of inflammable  nitre,  given  by  the ancient chemists.
The nitrate of ammonia is  obtained  by uniting directly
ammonia with nitric acid; the  ammonia must be in ex-
cess,  because a  part  volatilizes during  evaporation.
This salt is formed of  54 of acid, and 17 of the base.
   Nitrate of Barytes.   (Nitrate de Baryte.)   A co-
lourless salt, of a sharp taste, capable of being  crystal.
lized in octoedrons, which contain no water of crystalli-
zation, are unalterable by the air, soluble in 20 parts of
water at 32°, and in 3 parts at 212°.  Barytes forms in-
soluble salts with many acids ; it follows that the solution
of the nitrate  is precipitated by many of  them, but chiefly
by the sulphuric and krameric ; the latter appears to have
even a greater power than the former to  separate barytes
from its combinations.   The nitrate of barytes is obtained
by calcining  strongly  in  a crucible a  mixture of char-
•  oal  and  native  sulphate  of barytes.   The sulphured
                          25 
290
M  I  T
of barium which is obtained is diluted in 10 parts of wa-
ter ;  an excess of  nitric acid is added ; the liquor is eva-
porated ; by the water of barytes is precipitated a little
of iron which it contains ; it  is filtered and crystals ob-
tained.   The  nitrate of barytes  is often  employed as a
re-agent.  It  is composed of 54 of acid  and 78  of the
base.
  Nitrate of  Bismuth.  (Nitrate de Bismuth.)   Ap-
pears in the form of large colourless  crystals;  its taste
is first  astringent, afterwards  very caustic.   It  contains
much of the water of crystallization.   It is  obtained by
treating bismuth with nitric acid.   Water decomposes this
nitrate, giving place to  a  precipitate of an insoluble sub-
nitrate, formerly called magistery of bismuth, and  to an
acid  nitrate which remains in  solution; this solution pre-
cipitates white with ammonia, black with sulphuretted hy-
drogen, and yellowish or  greenish white with the hydro-
ferro-cyanate   or   ferro-cyanide  of  potassium,  orange
yellow with the chromate of potash, and white with albu-
men.  The sub-nitrate can be  dissolved in nitric acid,
and then presents the same characters as the acid solu-
tion.
  Nitrate of  Cadmium.  (Nitrate  de  Cadmium.)   A
colourless salt, which attracts  humidity from the  air, con-
tains much of the water of crystallization, is very solu-
ble,  and susceptible of  crystallization in acicular prisms,
often in clustered circles.  It is obtained by treating cad-
mium with nitric acid.
  Nitrate of Cerium.  (Nitrate de Cerium.)  Cerium
can  form two nitrates.   The   proto-nitrate, which is ob-
tained by uniting the protoxide of cerium to nitric acid, is
colourless, of a pungent taste, a little sugared, deliques-
cent, and reddens the tincture of litmus.   The deuto-ni-
trate, which is obtained  in heating the deutoxide of ce-
rium with nitric acid, is of a yellowish colour, of a taste
similar to the  proto-nitrate ; it cannot  be crystallized «n- 
N I T
291
less it contain a great quantity of acid.  These substances
are without use.
   Nitrate of Chrome.   {Nitrate de Chrome.)  This is
little  known.
   Nitrate of Cinchonine.  (Nitrate de Cinchonine.)   It
is obtained by uniting directly cinchonine to nitric acid
diluted  with  water, and slowly evaporating the solution.
The nitrate separates  in the form of a limpid oil, which
collects in little drops ; it crystallizes in prisms.
   Nitrate of Cobalt.   (Nitrate de Cobalt.)  A violet
red salt, susceptible of producing crystals which  attract
moisture  from the air, and  are  very  soluble in  water.
The  cyanide of potassium  precipitates  this  solution a
very clear brown ;  the ferro-cyanide of the  same  metal
precipitates it a clear green ;  but sulphuretted hydrogen
does not precipitate it.  This salt is obtained by submit-
ting arsenical cobalt to a  number of successive  opera-
tions.   See Cobalt.
  Nitrate  of Copper.    (Nitrate  de Cuivre.)  Blue, of
a sharp and caustic taste, crystallizes in prisms, often aci-
cular.  It is very soluble in water ; its solution is decom-
posed by sulphuric  acid ;  the sulphate, less soluble than
the nitrate, easily crystallizes.  The solution of the nitrate
of copper is  precipitated  black  by sulphuretted  hydro-
gen, blue by  ammonia, green by  the deutoxide of arse-
nic, and a chestnut brown by the ferro-cyanide of potas-
sium.   The nitrate of copper is obtained by treating this
metal with nitric acid.
   Nitrate of Gold.  (Nitrate  d'Or.)  The deutoxide
of gold, can be dissolved only in concentrated nitric acid ;
the combination is very feeble, and the nitrate is decom-
posed if submitted to evaporation.   Water  decomposes
it by  uniting with its nitric acid.
   Nitrate of Glucina. - (Nitrate de Glucine.)  Colour-
less,  deliquescent,  uncrystallizable,  of a sugared taste ;
is very soluble  in water, and reddens  the  tincture  of 
292
N  I T
 litmus.  Its solution is not precipitated by sulphuretted
 hydrogen;  with potash  and soda  it forms a white pre-
 cipitate which an excess of the alkalies can re-dissolve. It
 is obtained  by treating glucina with nitric acid, and eva-
 porating the solution to dryness.
   Nitrate  of Iron.  (Nitrate de Fer.)   Of  this  there
 are  the  deuto-nitrate  and the  trito-nitrate.  Nitric acid
 causes the protoxide of iron to pass to its highest state of
 oxidation.   The deuto-nitrate may  be crystallized; it is
 soluble in water ; its solution can dissolve a certain quan-
 tity of the deutoxide of nitrogen; it is precipitated bluish
 green  by the cyanide of potassium ; it is not precipitated
 by sulphuretted  hydrogen.  This salt is obtained  by in-
 troducing iron into dilmed nitric acid and  concentrating
 the solution by a gentle heat.
   The trito-nitrate is always acid, of a beautiful red colour:
 it is uncrystallizable ;  it is precipitated white by the ferro-
 cyanide of potassium.   In attempting to bring it  to the
 solid state by evaporation, it decomposes and remains in
the state of a tritoxide.   It is obtained by  treating iron
 minutely subdivided, in nitric acid diluted with its  weight
of water.   There is always a  portion of  the ritoxide
which  is not attacked by  the acid,  and which remains at
the bottom of the vessel.
   Nitrate of Lead.  (Nitrate de Plomb.)  White and
opaque, of  a sugared  and astringent taste, soluble in 8
parts of water at 59°.   Its evaporated solution produces
tetrahedral crystals  which contain no water of crystalli-
zation. If boiled with thin plates of lead,  the latter ab-
sorbs a portion of the  oxygen of the nitric acid, and the
salt  is transformed  into a sub-hypo-nitrite.    The  solu-
tion of nitrate of lead  is precipitated black by sulphuret-
ted hydrogen, white by the ferro-cyanate (cyano-ferrure)
of potassium.   This salt is obtained by diluting litharge
 (deutoxide  of lead) in weak nitric acid.  It crystallizes
by evaporation. 
N I T                     293
   iNitrate of Lime.  (Nitrate de Chaux.)   Colourless, of
 ■i sharp taste, very deliquescent, soluble in water, dissolves
 also in alcohol, which leaves it to crystallize by evapora-
 tion.  If into its concentrated aqueous solution a certain
 quantity of liquid potash  is poured, the lime  being  set
 free immediately absorbs the water of  the  solution and
 forms a solid hydrate.  This phenomenon was formerly
 called Miraculum Chimicum.  The nitrate of lime is fre-
 quently  found in nature, but always in small quantities.
 It is collected with the nitrate of magnesia for the prepa-
 ration of the nitrate of potash.   To obtain the nitrate of
 lime  pure, it  must be prepared directly-with nitric acid
 and lime or  a very  pure carbonate of lime,  as white
 marble.
  Nitrate of Lithium.  (Nitrate de Lithium.)  Colour-
less,  very  deliquescent, very  soluble, crystallizing in
rhomboids or  in needles ; its taste is fresh and sharp ; it
melts easily and is obtained directly.
  Nitrate of Magnesia.   {Nitrate de Magnesie.)   A
colourless salt of a bitter taste,  deliquescent, very  solu-
ble, crystallizing usually in acicular prisms.   Potash and
soda  precipitate  magnesia; ammonia  precipitates  one
part only and forms  an ammoniaco-magnesian nitrate.
It exists with  the nitrates of lime and potash in saltpetre
beds.
  Nitrate of  Manganese.   (Nitrate  de  Manganese.)
The proto-nitrate only is known;  it is  very soluble and
with difficulty crystallized.  Its solution is precipitated
white by the ferro-cyanate of potassium, and  yellow by
the simple cyanide.   It is obtained by treating the oxides
of manganese with nitric acid.
  Nitrate of Mercury.  {Nitrate de Mercure.)   Mer-
cury can form two combinations with  nitric acid.  The
proto-nitrate is with difficulty obtained, it often  contains a
small portion of the deuto-nitrate.   To  obtain it, 18 parts
of nitric acid  at  77°,  10 parts of water, and 20 parts of
                          25* 
294
N I T
mercury are mixed and heated  in  order to favour then
combination.  It was formerly prepared by heating mer-
cury with very feeble nitric acid; the result always was
a deuto-nitrate, or at least a mixture of the two salts ;  so
that if a solution  of chloride  of sodium  (common salt)
was added, no precipitate was formed, the result being u
deuto-chloride, which is soluble.   This salt is white.
very sharp;  in contact  with the  air it decomposes into
an  insoluble sub-proto-nitrate and a soluble acid  proto-
nitrate.  In  order to effect its solution, the water must
be slightly acidulated to prevent its decomposition.   It
may be known  when the salt  is in  the state of a  proto-
nitrate, by pouring into  it a solution  of chloride of so-
dium, which, if this is  the case, will form a white pre-
cipitate of the proto-chloride. If it is in the state of a deuto-
nitrate, the salt will remain in solution.  The  liquor is
filtered and  a solution of potash added ; if it contains the
deutoxide it will be precipitated yellow, otherwise  it will
be black.
  The deuto-nitrate is obtained by  boiling mercury with
an excess of nitric acid, until the solution is not precipi-
tated by a solution of the chloride of sodium.   It is then
evaporated; a crystallized mass of whitish, sometimes yel-
lowish, needles is obtained.   Hot water decomposes this
as it does the proto-nitrate,  and the insoluble part which
is obtained was formerly known  by the  name  of turbith
nitreux.  The solution of the deuto-nitrate is precipitated
yellow by potash,  white  by ammonia and the ferro-cya-
nate of potassium, and  yellow by the cyanide of  potas-
sium.   It is  not precipitated by the chloride of  sodium.
Sulphuretted hydrogen forms with it an orange and  some-
times  a black precipitate, which in a short time becomes
white.   This salt is in pharmacy employed in the prepa-
ration  of red precipitate (deutoxide of mercury) and of
3ome mercurial salts,  which are obta ned by double de-
composition.    With  the proto-nitrate is prepared  the 
N I T
295
soluble mercury of Hahnemann,  a medicine  which is in
high repute in tne north of Europe.  It  is  obtained by
pouring ammonia into a sol ition of this salt, a black pre-
cipitate i- formed, the liquid is filtered, again precipitated
by ammonia, again filtered, and this process is continued
until no precipitate is formed by ammonia ;  the ammonia
must not be in excess, but the liquor should always con-
tain some of the nitrate in solution.
   Nitrate of Morphine.   (Nitrate de Morphine.)   It is
bitter,  is easily dissolved in water,  and crystals may be
obtained.   It  is prepared  by treating morphine  with di-
luted nitric acid and gently evaporating the solution.
   Nitrate of Nickel.  (Nitrate de Nickel.)  This  salt
is  of a  green colour, of a taste at first sugared and  after-
wards  styptic;  it  dissolves  in double  its weight of
cold water.  The solution  on being evaporated  crystal-
lizes in 8-sided prisms, which retain much  of the  water
of crystallization.   Its solution is not precipitated by sul-
phuretted  hydrogen, but  it  forms an  apple-green  precipi-
tate with the ferro-cyanate of potassium, an ■ a yellowish
white with the simple cyanide of the same metal.  (See
Nickel.)
   Nitrate of Palladium.   (Nitrate  de  Palladium.)
Scarcely known; it is  red, soluble, and is precipitated
>>live green by the ferro-cyanate of potassium.
   Nitrate of Potash.  (Nitrate de Potasse.)  Saltpetre.
A  white salt, of a cool and sharp taste, fuses upon burn-
ing coals.  It attracts moisture  from  the air only when
the latter is very humid.   In commerce it is found in con-
fused  crystallized  masses.  If redissolved  and crystal-
lized anew, it is obtained in 6-sided prisms, terminated by
dihedral summits ; when  exposed  to the action of heat
it  fuses ;  in this state if one sixteenth part of sulphur be
added, on cooling, a mass is obtained known by the name
of Mineral erystal.
   The fusion  which this nitrate experiences is the igne-
ous, for it enntnins nn  w^tor of crystallization.  It dis- 
296
N I 1
solves in 4 times its weight of water and in { its weight
of boiling water.   By  calcining  the nitrate of potash
with the cream of tartar, (supertartrate of potash,) a sub-
carbonate of potash is obtained ; this however is not per-
fectly pure,  as it contains a little  lime; this preparation
was formerly called " Nitre fixe par le  tartre."  By cal-
cining the nitrate of potash with charcoal  a sub-carbo-
nate more pure than the preceding is obtained ; this was
formerly called " Nitre fixe par le charbon."
  The nitrate of potash is still used to  prepare  nitric
and sulphuric acids;  it  forms  an important part of gun-
powder, and is used in fulminating powder, &c.  It is of
frequent use in medicine.  It  is found  on the surface of
the earth, usually existing with the nitrates of lime and
magnesia in places where animal substances have under-
gone decomposition.  It is found  in the form of mould,
constituting  efflorescences of  saltpetre upon damp walls,
in cellars, and under old buildings.   It  is  obtained pure
by lixiviation.   The nitrate of potash is formed of 100 of
acid, and 87-146 Of the  base.
  Nitrate  of Quinine.  (Nitrate de Quinine.)   Exists
in  rhomboidal  prisms with an oblique base ;  it  offers
much the same phenomena as  the  nitrate  of cinchonin,
hut the  form of the  crystals is  very different;  those of
the nitrate of quinine are rhomboidal prisms with oblique
bases.
  Nitrate  of Rhodium.  (Nitrate  de Rhodium.)  It is
only known  to exist, and to be of a red colour.
  Nitrate  of Silver.   (Nitrate  d'Argent.)    Lunar
Caustic.  Colourless, bitter, very  caustic, very soluble
in water.  It appears not to  be deliquescent.   Crystals
are obtained from it which seem to have no determinate
form.   It colours the skin black and disorganizes animal
substances.   It is obtained by  dissolving at a mild heat
grains of silver with nitric acid.   When pure silver can-
not be  obtained, but alloyed silver as  in coin is to be 
i
N I T
297
 used, the nitrate of silver should be separated as much
 as possible by crystallization.  A blue liquor will at first
 remain, this will contain some silver; in order to sepa-
 rate it from the copper  a solution of chloride of sodium
 should be introduced, which  will form an insoluble chlo-
 ride with the silver.   When  it  will no longer form a pre-
 cipitate  it must be washed,  then calcined with an oily
 substance and poured into water; the silver will be found
 very pure.  With  the nitrate of silver is prepared the
 lapis infernalis, or infernal stone, a name given on ac-
 count of its strong  burning property.  The nitrate of sil-
 ver is formed of 100 of acid and 214.380 of the oxide of
 silver.
   Nitrate of Soda.   {Nitrate  de Sonde.)  This salt re-
 sembles  in some of its  properties the nitrate of potash :
 its crystals are rhomboidal  prisms, soluble in water.  It
is obtained by decomposing the sub-carbonate of soda
with nitric acid.  Great quantities of it are found in Peru.
It is composed of 100 of acid and 57-745 of the base.
  Nitrate of Strontian.  (Nitrate of Strontiane.)  A
 colourless  salt of a sharp  taste ; crystallizes  in octoe-
 drons, which dissolve by contact with the air.   It is pre-
 pared like the nitrate of barytes.
  Nitrate of  Tin.   (Nitrate  d'Etain.)   When  tin is
brought  into  contact  with concentrated nitric acid, the
 action is very lively,  even at  the  ordinary  temperature  ;
the tin passes to the state of a  deutoxide by the decom-
position of one part of nitric acid, and remains  at the bot-
tom of the vessel without combining with the portion of
acid not  decomposed ;  but if nitric acid  diluted with wa-
ter  be employed, it will only form the  protoxide, which
will combine with the  portion of acid  not decomposed,
and produce a proto-nitrate.  In  both  cases  there is a
formation of the nitrate of ammonia, owing to union of
the hydrogen of the decomposed water with part of the
nitrogen of the nitric acid. 
298
N I T
   The proto-nitrate of tin is uncrystallizable ; its solution
 is yellowish, and when an attempt is made to obtain it in
 a very concentrated state it decomposes,  giving place to
 a deposite of the protoxide of tin.
   Nitrate of Tellurium.   (Nitrate de  Tellure.)   Co-
 lourless ;  crystallizes  in  very elongated  prisms, which
 arrange themselves in groups.  Its solution is precipitated
 orange brown by sulphuretted hydrogen.   This nitrate is
 obtained by treating tellurium with nitric acid.
   Nitrate of Titanium.  (Nitrate de Titane.)   A white
 salt, reddens the tinciure of litmus,  crystallizes in rhom-
 boidal flat prisms.  Its solution is  precipitated reddish
 brown by the ferro-cyanate  of potassium.  This nitrate
 is prepared by treating with nitric acid the oxide of the
 metal calcined with potash, and purifying it by washing.
   Nitrate of Thorinium.  (Nitrate de Thorine.)  Very
 astringent,  uncrystallizable ;  notwithstanding  its  great
 solubility,  if by  careful evaporations its  solution can be
 brought  to a sirupous consistence, then  exposed to the
 air and  aftewards heated  in a sand-bath, it  becomes
 opaque and insoluble.   This nitrate is obtained by treat-
 ing a jelly of thorinium with  nitric acid.
   Nitrate of Uranium.   (Nitrate d'Urane.)   Uranium
 forms two salts with nitric acid;  but the  proto-nitrate is
 little known.  The deuto-nitrate is of a yellowish green,
 very soluble in water; its solution is precipitated by pot-
ash and soda not carbonated.   It forms  with the ferro-
 cyanate of potassium a red precipitate, and with the sim-
 ple cyanide  a  yellowish white  precipitate.  If exposed
to a certain degree of heat, it changes into a yellow sub-
deuto-nitrate, which is entirely decomposed if  the  tem-
perature  continues to be elevated.   This nitrate is either
obtained  by uniting nitric acid directly to the  deutoxide
of the metal, or by extracting it from phosphated uranium
 which exists in nature ; in the latter case,  the mineral is
 r-nlcjned  with double its weight of carbonate of  soda, the 
N  I T
299
product is submitted to repeated washings ; the residue is
dissolved in nitric acid and crystallized.
   Nitrate of Yttria.  (Nitrate d'Yttria.)   A colour-
less salt, of a taste at first sugared, afterwards astringent,
deliquescent,  crystallizing with difficulty; it reddens the
tincture of litmus.   Its solution is precipitated white by
potash and soda.  It is prepared by a direct process.
   Nitrate of Zinc  (Nitrate de Zinc.)  Colourless, of
an astringent taste, deliquescent, very soluble. Its evapo-
rated solution produces crystals in4-sided prisms terminated
by points with 4 faces.   It forms with the ferro-cyanate of
potassium, the simple  cyanide of this metal ; with pot-
ash  and soda it  forms white precipitates; sulphuretted
hydrogen also forms with it  a similar precipitate.   This
nitrate is prepared by treating zinc with weak nitric acid.
   Nitrate  of Zirconium.  (Nitrate de  Zircone.)   A
white salt,  of  an astringent  taste, uncrystallizable, red-
dening the tincture of  litmus ; it gives by evaporation, a
transparent  viscous  mass, little  soluble  in water.   This
nitrate is  obtained by treating a jelly of the zirconium
with nitric acid.
   Nitre.  (Greek, Nitron.  Latin, Nitrum.)   The  com-
mon name for saltpetre, or the nitrate of potash.
   Nitre Ammoniacal.  A  name formerly given to the
nitrate of ammonia.
   Nitre Calcareous. (Nitre Calcaire.)   A name given
by ancient chemists to  the nitrate of  lime.
   Nitre Cubic  (Nitre Cubiquc.)  An ancient name for
the nitrate of  lime.
   Nitre  Inflammable.   An  ancient name for the ni-
irate of ammonia.
   Nitre Magnesian.   Ancient name for the nitrate of
magnesia.
   Nitrification.   The  process of the formation  of
nitrates.   This  formation takes  place   only  when ni-
trogen and  oxygen  in a  nascent state  are in contact. 
300
N  I  T
 and when the  nitric  acid which  is  the  result of  the
 combination  of these two gases,  meets with a salifia-
 ble base which possesses a strong affinity  for the acid.
 Thus in nature  we find only alkaline nitrates.   It being
 known that in nature nitrates are never found except in
 places exposed to  animal exhalations, and continued
 dampness, artificial  manufactures  of  nitre (nitriires)
 have been successfully attempted ; in this process  it is
 necessary to use earth, or calcined  substances which are
 not too  dense, and which  may  be  easily penetrated by
 water. Thus marble and other compact calcarious mine-
 rals and all quartzose minerals do not promote the forma-
 tion of nitrates  in the  most favourable situations.  (Sec
 Nitrate of  Potash.)
   Nitrites.    These  are little known;  when nitrous
 acid is brought in contact with a  salifiable base, the result
 is a nitrite and a hypo-nitrite.
   Nitrites (Hypo.)  They offer characters analogous
 to those of the nitrates ;  like them they are decomposed
 by heat, and dissolved by water except their base  is in
 excess.   Many acids decompose them, and the hypo-ni-
 tric acid which  cannot exist uncombined is transformed
 into nitric acid and deutoxide of nitrogen.   The hypo-
 nitrite, of  lead  is obtained by boiling the  nitrite of lead
 with metallic lead ; a sub-hypo-nitrite is formed, which is
 brought to a neutral state, by precipitating a portion of
 the  base  by sulphuric acid.  With  this neutral hypo-
 nitrite many others can be obtained by double decompo-
sition.  According to Berzelius,  in  the neutral hypo-ni-
 trites the quantity of  the  oxygen of the oxide is to the
 quantity of the  oxygen of the acid as 1 to 3; but in the
 sub-hypo-nitrites, the quantities of the base vary as in the
sub-nitrates.
   Nitrogen.   (Azote.)  (From the Greek nitron, which
 signifies nitre, and gennao, to generate, because it is the
 generator of nitre.  The  French term, azote, signifies a 
N O M
301
destroyer of life.)   A colourless gas, inodorous and insi-
pid ; it extinguishes combustion; its specific gravity is
0-9757.  It has never been decomposed; it constitutes
one of the  simple non-metallic bodies.  Some chemists
have considered it  as the  oxide of a metal which they
have termed nitricum; others as one of the oxides of a
metal which they call ammonium.   As neither of these
hypotheses has been established by experiments, we must
regard  nitrogen as  a  simple  substance.   It combines
with oxygen in 5 proportions, notwithstanding its affinity
for this body is but feeble ; this combination never takes
place by merely bringing the two gases in contact.  It
has as little affinity for other substances.
   The firmest combination of  nitrogen is-with hydrogen,
forming  ammonia.   Combined  with  carbon, it forms cya-
nogen.   It unites to chlorine, iodine, but with none of the
metals except potassium and sodium.
   Nitrogen forms f  of the atmosphere ;  it is a constituent
part of animal  substances.   It is of little use in an un-
<:ombined state.  It was formerly called alcaligene.  It
is obtained by burning,  under  a bell-glass containing
atmospheric air, some substances  so combustible as to
absorb all the oxygen from the air, leaving the nitrogen
pure.  Phosphorus  is often employed for  this  purpose;
nitrogen may  also be obtained from liquid  ammonia, by
decomposing it with liquid chlorine.
   Nitrogen Carbonated.  See Cyanogen.
   Nitrogen Oxymuriated.   See Chloride of Nitrogen.
   Nomenclature Chemical.   The establishment of the
chemical nomenclature as it now exists is one of the great-
est services which could have been rendered to the cause
of science ; where, indeed, we may ask, would now
have  been the science of chemistry, if arbitrary names
only had been given to the numerous compounds  which
have been  and are constantly discovered ? What chemists
                         26 
302
N O  M
 could  ever learn this crowd of names, which when re
 called bring with them  nothing to point out the nature of
 the bodies composing them ? But by the aid of the chemi-
 cal nomenclature, the name of a salt, an oxide, an acid, or
 any other compound, gives at once the composition of the
 substance, and  of course suggests most of its important
 properties.  This  nomenclature  is due  to  Guyton Mor-
 veau.
   There exists  a certain number of simple  bodies (See
 Elements); the names of them are unimportant, provided
 they are not too long.   Different terminations  affixed to
 the names of these elementary bodies, constitute all the
 nomenclature of chemistry. These simple bodies, oxygen
 excepted, take also the name of combustible bodies, be-
 cause that all can  form  combinations with oxygen, and
then take the general name of burnt bodies.   We have
 then two great  divisions ; simple combustible bodies, and
 burnt bodies.  The  combustible bodies can  form amono-
themselves a great number of combinations;  these com-
pounds have received different names.
   When they are solid or liquid, the name of one of the
compounds is terminated in  ure, and  this is  followed bv
the name  of the other; as iodure of azote, sulphure of
 lead, chlorure of sodium, hydrure of sulphur, &c, to de-
 signate the combination  of iodine with azote, of sulphur
 with lead, of chlorine with sodium, and of hydrogen with
 sulphur.*
   Sometimes however,  for greater  simplicity, the names

  * The translator has here followed the French nomenclature ; it is necessary.
 however, to admonish the English student that our terminations do not corn-,
 pond with those of the French ; their termination in ure, is in many cases trans
 'ated by ide, thus iodure d'azote is iodide of azote ; chlorure de sodium, is chlo ■
 ride of sodium, &c. ; in other cases the termination in ure is answerable to uret
 as sulfure de plomb is sulphuret of lead, Sec.  The French nomenclature in this
 as in many other cases presents a greater simplicity than the English, and is
 more accordant with scientific principles. 
NOM
303
of the simple bodies are given to binary compounds as
azoted hydrogen is sometimes called ammonia;  carbonated
azote, cyanogen, &c.; and their combinations with  com-
bustible bodies are called ammoniures,  and cyanures  more
commonly ammoniurets and cyanides.  Common use has
however more influence than rules of nomenclature ; thus
if combination takes place between two metals, the com-
pound is called an alloy, or amalgam if mercury is one of
the compounds ; we would not say an orure of copper, an
argentine of mercury, but an alloy of gold and copper, and
an amalgam of silver.
   In the second class of burnt bodies or such as  unite
with oxygen, the  general name of oxide is given to the
binary compounds which result from the union of simple
substances with oxygen, when their compounds do not
present acid  properties ; and as these combinations can
take place in different proportions, they are called proto,
deuto, trito, and per oxides, according as the simple sub-
stance is oxidated to the first, second, third,  or highest
degree;  thus we  say the oxide  of  carbon,  protoxide,
deutoxide, &c, of iron.  When  oxygen uniting with a
substance gives it the peculiar properties described under
the term acid, the  compound takes the general name of
acid, but as  one substance may with oxygen form differ-
ent acids ; the termination ic  {ique) is  used to denote the
highest portion of oxygen, that of ous (eux) the lowest;
thus  phosphoric  (phosphorique)  acid  and phosphorous
(phosphoreux) acid ; when a substance forms with oxygen
but one acid, the termination is in ic as carbonic acid.  In
 some cases a simple body may form more than two  acids,
the term hypo signifying under is then used ; commencing
with the highest portion of oxygen, we would say :
               Phosphoric      Acid.
               Hypo-Phosphoric  "
               Phosphorous       "
               Hypo-Phosphorous " 
304
O  I  L
  The acids formed with hydrogen  are  designated  bv
prefixing the word hydro, as hydro-chloric, hydro-sulphu-
ric, (sulphuretted hydrogen,) &c.
  The acids can  combine  with  most of the  oxides, and
form compounds distinguished by the name of salts.   A
salt formed with  an acid ending in ic is  known by the
termination ate, if the name of the acid ends in ous that
of the salt terminates  in  ite.  Thus we  would say the
sulphate of the protoxide of lead; sulphite of the protoxide
of potassium.  When there is an excess of the base it is
called a  sub-salt; when there is an excess of acid it is
called a  super-salt, or an  acid salt; as the sub-nitrate of
bismuth; the acid or super-sulphate of alumine.  The ter-
mination (more frequent in English) ine is used to desig-
nate organic salifiable bases, as  Narcotine, Quinine, &c.
  Numbers Proportional.  Numbers which  indicate
the proportion in which  substances unite.   See Atom.

                          o.

  Oil.   (Huile.)  (In Latin Oleum, from olea, the olive,
this name being at first confined to the oil expressed from
the olive.)  Oil  is a substance of a fatty or unctuous
nature, either solid or fluid, does not combine with water,
burns with flame, and  is  volatile  in different degrees.
Oils are never formed but in organic substances ; all the
minerals which  present oily characters have originated
from  the action of vegetable or animal life. They are
distinguished intoned and volatile or essential oils.
  Fixed oils (huiles grasses) are  usually fluid at the ordi-
nary  temperature, are  lighter than water,  inflammable,
more or less soluble in ether and  alcohol, and insoluble
in water;  they combine more or less easily with metallic
oxides, forming soaps which arc soluble or  insoluble ac-
cording to the nature of the oxides.  The  fixed oils com-
bine in all proportions with the essential oils.  Exposed to
the action of the atmosphere, they become thick, and lose 
                        OLE                    305

 their fluidity.   Such as dry so hard as not to affect paper
 when applied to them are called  siccative  oils;  linseed
 oil is of this kind ; hence  its use in painting.  When the
 fixed oils are submitted to distillation, they furnish much
 carburetted hydrogen and other products common to fat
 substances. According to Chevreul, all the  fixed oils are
 composed of elaine and stearine in different proportions.
   Oil of Vitriol.   {Huile  de Vitriol.)  The common
 name of sulphuric acid, probably given on account of its
 oily appearance.
   Oils  Volatile or Essential.   {Huiles Volatiles ou
 Essentielles.)  Pungent, caustic, odoriferous ;  many are
 without colour, others are yellow,  green, or blue;  most
 of them are lighter  than  water, all  are volatile ;  they
 easily absorb oxygen, and  then become more consistent;
 some even are solid.   Some form a crystalline substance,
 as the oil of turpentine.  These oils do not combine inti-
 mately with salifiable bases, the result of the combination
 being a kind of soap (savonules).  It is not known whether
 these oils are formed of two or more immediate principles;
 according  to many analyses, they  consist of hydrogen,
 oxygen,  carbon, and  nitrogen.   Saussure, who studied
 much into the nature of these substances, found no oxy-
 gen in the oils of lemon and turpentine.  The essential
 oils exist in all aromatic vegetables ; many are obtained
 by distillation with water.
   Oleates.  Combinations of oleic acid with salifiable
 bases ; these salts are decomposable by fire and by most
 of the acids.  Oleic acid unites to  bases in different pro-
 portions, giving rise to  acid, neutral, and   sub-oleates.
 According to the experiments of  Chevreul, oleic acid
 possesses the same capacity of saturation as the marga-
ritic  and stearic acids.  The oleates of lime, barytes,
strontian, magnesia, zinc, dec, are insoluble and pulveru-
lent ;  they are prepared  by double decomposition.
                         26* 
306
OP I
  Oleate of Potash.  {Oleate de Potasse.)  Of a bittei
taste, alkaline, pulverulent, and colourless.  It is very
soluble, and attracts humidity from the air; dissolved in
two parts of distilled water it  forms a jelly, and in four
parts, a  liquid of sirupous consistence ;  if dissolved in a
great quantity of water, it decomposes into a sub-oleate
and potash.  Most of the acids decompose it, also  the
solutions of lime, barytes, strontian, and most of the me-
tallic  salts.   It is obtained by  heating  moderately in a
capsule one part of potash with one part of oleic acid and
four or five parts of  water, and  suitably evaporating  the
mixture.
  Oleate of Soda.  {Oleate de Sonde.)  Is  prepared
like the preceding;  the proportions are 1 part oleic acid.
0-66 of pure soda dissolved in 5 parts of water.
  Olivile.   A white, pulverulent, inodorous  substance.
of a bitter and aromatic taste ; it is sometimes obtained in
little  acicular crystals; exposed to a high temperature..
it melts and becomes yellow; at a still  higher tempera-
ture,  it decomposes like vegetable  substances ; it  is
almost insoluble in  cold  water, but dissolves in boiling
water; the liquid on cooling  becomes milky by the pre-
cipitation of the olivile;  it becomes limpid on boiling
anew ; if the ebullition is long continued, this substance
separates, and appears on the surface in the form of an
oily liquid.  The  olivile  exists in the gum of the olive
tree ;  it was first extracted by Pelletier;  for this purpose
the gum is dissolved  in highly rectified alcohol; on stand-
ing a  short time, the liquor deposites the  olivile in  the
form  of little needles;  it  is redissolved   in alcohol, and
then washed with a little sulphuric ether,  in order to sepa-
rate the remainder of the  colouring matter.
  Opium.   (From the Arabian opi,  juice, it being  obr
tained from the juice of the poppy.)  A gum-resinous
extract from the Papaver somniferum, or white poppy.  In
various parts of Asia fields of poppies are cultivated fqr 
ORE
307
this use.  Incisions are made into the stems and capsule
of the poppy ;  the juice is collected, and evaporated by
gentle  heat.   Exposed to  the action of fire, opium de-
composes ; when heated  in contact with the air, it in-
flames,  and absorbs oxygen.  By analysis it has been
been found to  consist of
     Meconic  acid,.......2 parts.
     A new acid discovered by Robiquet,   3
     Morphine,   -.......1
     Narcotine,........  2
     A substance analogous to caoutchouc,  5
     Mucilage,........6
     Fecula,.........  7
     Resin,     .........8
     Fixed oil,   ........9
     Vegeto-animal matter,.....10
     Sand and other impurities,   -  -  - 11
  Orate.  A  name given by Pelletier to  designate a
iombination of the oxide of gold (or) with potash.  When
a great excess of alkali is added to a solution of the chlo-
ride of gold, the liquor immediately becomes discoloured,
and  takes a yellowish  green tint which disappears by
adding a little water.  A precipitate of the oxide of gold
retaining a little of the potash is formed ;  an acid restores
the yellow colour.   Pelletier supposes that the hydrated
oxide of gold performs the part of an oxide in relation to
the potash, and that it forms a very alkaline  orate which
is soluble in water; that by adding an acid it produces a
salt based  upon potash, and  muriate of  gold by the de-
composition of the orate of potash.  Thenard and some
other chemists believe  that this salt is but  a  double  salt,
because that the muriate of gold uniting to the muriate of
potash  forms  a compound which cannot be  precipitated
by an alkali.
   Ore.  {Mine.)  The mineral substances from which
metals  are extracted. 
308
O  X A
    Ore of Black Lead.  A name sometimes given to
  the per-carburet of iron.
    Ore of Red  Lead.   (Minium.)  See Tritoxide  of
  Lead.
    Orpiment.  See Sulphuret of Arsenic.
    Osmazome.  A yellowish  brown extract,  soluble  in
  water and alcohol, procured from the muscles of animals.
  It gives a peculiar odour to soap.
    Osmium.   A solid, pulverulent metal, of a blackish co-
  lour.   As it has never been fused, its physical properties
  are not well  known.  Heated in contact with  the air, it
  absorbs oxygen  gas and becomes a white volatile oxide
  with a most powerful odour. It has been hitherto combined
 only with chlorine and a few metals. According to Henry,
 it forms ductile alloys with gold and silver.  It is  never
 found but  in the ore. of platina, combined with iridium.
 It was discovered by Tennant in 1803.
   Oxacids.   This word is sometimes used to designate
 the acids formed of a combustible substance and oxygen.
   Oxalates.  Combinations  of oxalic acid with salifia-
 ble bases.   They are all decomposable  by fire, leaving
 little residue of charcoal on account of the great quantity
 of oxygen which the oxalic acid contains.   The oxalates
 present very interesting phenomena.  The neutral oxa-
 lates of alumine, potash, and soda, are the only ones, hav-
 ing for their bases metallic oxides,  which are soluble.
 Most of the others become soluble by the addition  of an
 excess of acid;  the former lose  their solubility by  the
 same  addition.  For this reason,  when  oxalic  acid is
 poured into a solution oflime or barytes, it forms a pre-
 cipitate which redissolves by adding an excess of acid ;
 while if to a solution of the oxalate of potash an excess
of the same acid be added, crystals of the oxalic acid are
formed.  Lime,  barytes,  and  strontian are the bases
which have the greatest tendency to unite  to oxalic acid.
In nature but four  oxalates are found;  those of iron, 
0  X A
309
lime, soda, and potash.   All the soluble oxalates are pre-
pared  directly by combining oxalic acid with the sub-
carbonates.  In the neutral oxalates the quantity of the
oxygen of the oxide is to the quantity of the acid as 1 to
5-568; in the acidulated oxalates as 1 to 5*568 multi-
plied by 2; in the acid oxalates as 1 to 5-568 multiplied
by  4 ;  and in the  sub-oxalates as  1  to 5-5G8  divided
by 2.
  Oxalate of Ammonia. (Oxalate d'Ammoniaque.) Crys-
tallizes in long prisms terminated by dihedral summits ;
it has  a pungent taste.   Submitted to distillation  in a re-
tort, it  furnishes the sub-carbonate  and  a portion of the
oxalate of ammonia which volatilizes ; there is little resi-
duum.   Water easily dissolves this salt; it is  insoluble
in alcohol.  Nitric, sulphuric, and muriatic acids abstract
a portion of its base, changing it  to an  acidulated oxa-
late.  It is said that when two solutions of equal parts of
corrosive sublimate and the  oxalate of ammonia are put
in a  dark place, the two salts suffer no alterations for
many days ; but if the mixture is exposed to the rays of
the sun,  an instantaneous action  is  observed, the liquor
becomes milky, and deposites a  certain  quantity of the
proto-chloride of mercury, disengages carbonic acid, and
the liquor becomes clear ; it contains only the muriate of
ammonia and a little of the oxalate of ammonia.  (Jour-
nal of Phar. tome I. p. 62.)   The oxalate of ammonia is
obtained in laboratories, by saturating a solution of oxalic
acid  with ammonia and evaporating it.  According to
Berzelius,  it is composed of 100 of acid and 47-679 of
the base.   It is frequently used as a re-agent to detect
the  presence of lime.  The acidulated oxalate of ammonia
is much  less soluble than the  neutral oxalate ; it is ob-
tained  in the same manner, except that double the acid
is employed in its preparation.
  Oxalate of Cinchonine.   Insoluble and pulverulent:
it is obtained by double decomposition.. 
310
O X 1
  Oxalate of Potash.   (Oxalate de Potasse.)   Exces-
sively soluble, almost uncrystallizable ; when decomposed
by fire, the sub-carbonate of potash is obtained for a  re-
sidue.   All the strong acids take from it a portion of its
base, and change it to the state of an acid oxalate, which
is  precipitated if the solution  is concentrated.   It pre-
cipitates with all the acids which can form insoluble oxa-
lates.   It is obtained by saturating  the salt of wood sor-
rel (Oxalis acetocella) with  potash.  The acidulated oxa-
late of potash crystallizes in short opaque parallelopipeds;
it reddens blue vegetable colours, is less soluble than  the
preceding ;  it does not attract moisture from the air.   It
is obtained very pure, by adding to a solution of potash
twice the quantity of oxalic acid which is necessary  un-
its saturation.
  Oxalate (Acid)  of Potash.  Sub-oxalate of potash.
Salt of sorrel.  This is less soluble  than  the neutral and
acid oxalate ;  it crystallizes easily.  It contains twice as
much  of the  acid as  the  acidulated  oxalate,  and four
times as much of the neutral  oxalate.  By some che-
mists it is called quadroxalate of potash.  In Switzerland
it is extracted from the common sorrel (Rumex aceto-
cella.)  The salt of sorrel is used for removing ink spots
and iron rust from linen.
  Oxalate  of Soda.  (Oxalate de Sonde.)  Exists in
small granular crystals having little taste : when decom-
posed by fire, it offers similar products to the preceding ;
it is obtained by the combination of soda with the juice of
Oxalis acetosella, rumex, dec.   The acidulated oxalate of
soda is  much  less  soluble, and reddens the  tincture of
litmus.
  Oxides Metallic.  (Oxides Metalliques.)  Compounds
which result from the combination of oxygen with metals.
The ancient chemists called  them metallic  lime, sup.
posing them to be metals deprived of an imaginary sub-
stance which they called phlogiston.  The most important 
0  X I
311
difference between the  metallic and other oxides, is the
property they  possess  of combining with  acids,  neu.
tralizing them, and forming  salts.   All  the oxides  are
brittle, solid, inodorous, (except that of osmium,) and in-
sipid, except those of the second class* (as  osmium and
arsenic.)   All the oxides are  heavier than water, and less
so than most of the metals.   None redden the tincture of
litmus, but many restore  its colour when reddened with
an  acid.  The oxides heated in close vessels, present
different phenomena; a  few are deprived  of all  their
oxygen ; others lose but a part; many retain it with great
tenacity.   Light has not a very perceptible  effect upon
them; though some chemists have asserted that it reduces
the oxide of gold.   Chlorine  decomposes many oxides,
disengaging oxygen, uniting to their metals, and thus trans-
forming them to chlorides: this however does not  take
place but at  an elevated temperature.   Liquid chlorine
does not combine with the oxides ; it decomposes them in
part, unites with the decomposed portion to form a chlo-
ride, while the oxygen of the  metal combines with a pari
of the chloride,  producing chloric acid which unites to the
portion of the metal  not deoxidized.  This experiment
succeeds well with potash. Iodine at  a high temperature
produces upon some metallic  oxides effects similar to
those of chlorine ;  that  is, by forming an iodide and dis-
engaging oxygen.   Through  the medium of water, it de-
composes  many oxides,  forming  iodides (iodures,) and
iodates.  Nitrogen has no action upon the oxides at any
temperature.   Sulphur, at an elevated temperature, de-
composes all  the  oxides of the last five sections;  with
all  the  oxides  of the  last  four sections,  it  disen-
gages sulphuric acid, and the deoxidated metal unites to
the sulphur;  with the oxides  of the second section, there
is a formation  of  a sulphate  and  a sulphuret (sulfure).
Sulphur through some medium presents nearly similar
* See Metals, Thenard's sections. 
312
O  X I
effects; yet according to Thenard, water is decomposed
with the alkaline oxides  in such a manner as to produce
hypo-sulphurous acid and sulphuretted hydrogen, which
uniting with a portion of the  base, form  a hypo-sulphite
and a hydro-sulphuret.   Phosphorus has no action upon
the earthy oxides ; it decomposes the oxides of the second
section, forming phosphates and phosphurets, (phosphures,)
with the oxides of the last four sections, it gives different
products.   When the oxide  may be easily reduced, the
result is a phosphuret and phosphoric acid ; when this is
not the case, there is  a formation  of a phosphuret  and
phosphate;  it would even be possible, if the metal  was
highly oxidated and had a great affinity for  oxygen,  that
only a phosphate would be obtained. Phosphorus united
to water exhibits different phenomena;  it acts only upon
the alkaline oxides  and those which are  easily reduced.
In the first case a phosphate is formed, and phosphuretted
hydrogen disengaged, a hydro-phosphite is also produced,
which proves that the water is decomposed ;  in the second
case the oxide is reduced, and  phosphoric  acid formed.
Carbon, at  a temperature more or less elevated, reduces
all the oxides except those of the first and second section ;
it disengages either carbonic acid or the oxide of carbon.
Electricity reduces all the oxides except those of the  first
section.   Selenium, according   to  Berzelius, produces
with the oxides effects similar to those of sulphur. •  The
hydracids in uniting to the oxides decompose them ;  the
oxygen of the oxide combines with the hydrogen of the
acid, forming water,  while the reduced  metal unites to
the disengaged base of the hydracid.
  Oxide of Aluminum.  (Oxide d'Aluminium.)   White,
smooth to  the  touch,  insoluble in water, and forming a
paste with  it, infusible by the fire of a  forge  furnace,
without action upon oxygen or atmospheric air; its spe-
cific gravity, according to Kirwan, is 2-000 ; it is seldom
found pure in nature ;  it exists in the sapphire, and is  fre- 
O  X i
313
quently combined with silex.  It was discovered in 1754,
by Margraff.  Many chemists have since  studied its na-
ture ;  they have until recently considered it as a simple
earth, which they designated by the name of alumine.
Since the discovery of the alkaline metals, chemists have
heen forced by analogy to add this substance to the list of
metallic  oxides.  Alumine is obtained  from  alum;  for
this purpose, alum is dissolved in about 20 parts its weight
of water;  ammonia is added until a precipitate is  no
longer formed.   The alumine   in precipitating, takes
always with it so much water as to give it the appearance
of a jelly ; after being well washed, it is  dried by heat.
Gay-Lussac has described  another process for obtaining
it; this is convenient and economical  when the object is
not to obtain the alumine in a jelly.   By  this  process, it
is only necessary to apply to the alum, for half an hour, a
heat sufficiently  great to  redden the crucible;  all  the
immonia, and all the sulphuric acid will escape, leaving
only the alumine in a very white powder.
  Oxide of Antimony  (Deuto.)    (Deutoxide d'Anti-
moine.)  White, reducible by the  voltaic pile, insoluble in
water, without action upon air or oxygen gas,  and unde-
 omposable by fire.   It is obtained  by pouring  diluted
nitric acid upon powdered antimony, slightly heating the
liquor, and then  adding  stronger acid.   The  metal oxi-
dizes  without dissolving, becoming a yellow white, then
A'hite  by calcination.  Berzelius states  that  this oxide
reddens litmus, and partly  saturates salifiable bases;  for
these  reasons  he called it antimonious acid.   According
to Thenard, it is composed of 26-07 of oxygen, and  100
of the metal.
   Oxide  of Antimony   (Proto.)   (Protoxide  d'Anti-
nioine.)  It is obtained by dissolving  in water the proto-
chloride  of antimony;  a white powder called  powder of
nlgaroth,  is immediately  precipitated;  this  is  a sub
chloride  of antimony.   This precipitate is heated with «
                         27 
314
O  X I
   solution  of potash, which unites with  the  chlorine am:
   sets free the oxide ;  it must be filtered and washed with
   many waters,  in  order to  be obtained pure.  Another
   method of obtaining the protoxide of antimony, is to heat
   antimony to redness in a long earthen crucible ;  a thick.
   white smoke is disengaged, which being condensed, forms
  a white crystalline substance, formerly called argentine
 flowers of antimony.   This, in its composition, is the same
  as the preceding  protoxide.   According  to Thenard.
  both contain 18-5 of oxygen to 100 of the metal.
    Oxide  of Antimony  (Thito.)  (Tritoxide  d'Anti-
 moine.)  At a high temperature it disengages a portion
 of its oxygen and becomes a deutoxide ; it is obtained by
 exposing to a red heat for.a considerable time, a mixture
 of 1 part  of powdered  antimony to 2 of the peroxide of
 mercury.   This oxide is formed in preparing that ancient
 composition, formerly known under the  name  of diapho-
 retic antimony.   For  this purpose  a mixture of equal
 parts of antimony and nitrate  of potash are thrown into
 a crucible and heated to redness ; a mass  composed of
 the peroxide of antimony and  potash  is obtained.  In
 this experiment, the oxygen of the nitric acid, goes to
 the antimony, and the potash unites in part to  the oxide
 formed.  By treating this mass with water,  the greatest
 part of the potash with a little of the antimony, dissolves ;
 the residue  constitutes  the diaphoretic antimony  which
 is a compound of 20 parts of potash and 80 of the  trit-
 oxide of antimony.*   According to Berzelius, the tritox-
 ide or peroxide of antimony is composed of 30-993 oi
 oxygen  to 100 of the metal;  the chemist calls  it antimu.
mac acid on account of its property of uniting to bases -
he admits also a fourth oxide of antimony, which he names'
sub-oxide ;  this, according to him, is formed by  exposing

 ; Re^elius remarks that this oxide thus obtained, can exist only in ,1k- *.■„
 '<  * hydrate, and that it would lose part of its oxygon by dedication   ' 
O  X I
315
 antimony to a current of humid air,  or to  the positive
 pole of the voltaic pile.
   Oxide  of Arsenic  (Deuto.)  (Deutoxide  d'Arse-
 nic.)  This oxide, known by the name  of white arsenic,
 rat's-bane,  and  arsenious acid, is white,  of a sharp and
 nauseous  taste ; when taken internally  it  disorganizes
 and ulcerates the parts in contact.  It is one of the most
 deleterious poisons,  occasioning death when  taken  in
 a very small dose.   The  deutoxide of arsenic is volatile,
 a property which it possesses in common with the oxide
 of osmium ; when it vaporizes,  it may be distinguished
 by an odour  resembling that of garlic ; it is soluble  in
 boiling water, does not redden blue vegetable colours ; on
 the contrary it greens the tincture of violets.   It is un-
 decomposable by fire, is  without action upon atmosphe-
 ric air and  oxygen gas ; when  heated with sulphur  it
 yields  all  its oxygen, burning one part of the  sulphur,
 and forming with the  other part a red sulphuret  of arse-
 nic.  It is found  in nature either in crystals or a pulve-
 rulent form ; but that which is used in commerce is obtain.
 ed from the wasting of the ore of arsenical cobalt.  The-
 nard considers this oxide as formed of 100 of metal and
 32-28 of oxygen.  The deutoxide of arsenic is employed
 in painting, in the manufacture of Scheele's green, dec. :
 it is also of use in medicine ; but on account of its poison-
 ous properties, it should be used with great care.   Ar-
 senic may be known  by being thrown on burning coals,
 where it gives off vapours which smell strongly of gar-
 lic ; its aqueous  solution is precipitated white by lime
 water ; sulphuretted  hydrogen gives it a yellow colour
 and precipitates  by the aid of heat the yellow sulphuret
 of  arsenic ;  this test is  so faithful, that according to
 Orfila, it would detect the one hundred thousandth part
 of white arsenic dissolved in a liquid.   The  solutions of
 sulphuret of  potassium and sulphuret of sodium, also
precipitate arsenic in  yellow flakes; but it is necessary 
316
O  X I
 to add  some drops  of strong acid,  that they may unitf
 with the base of the sulphurets, otherwise  there will  be
 no precipitates.   Legal writers upon medicine, have,  bj
 omitting this  circumstance, led to many errors in at-
 tempts to detect the  presence of arsenic.
  Oxide of Arsenic  (Proto.)  (Protoxide  d'Arsenic.)
 Black and pulverulent.  If heated in close vessels, this
 oxide decomposes to a  deutoxide and a metallic arsenic,
 for this reason  some chemists regard  it only as a mixture
 of metallic  arsenic and the deutoxide of arsenic.   Ber-
 zelius thinks it to be a peculiar acid ; he obtained it by ex-
 posing powdered arsenic for along time to the air ; it ap-
 pears to consist of 8 of oxygen to 100 of the metal.
  Oxide of Azote (Deuto.)   Deutoxide of Nitrogen.
 Nitrous  gas,  or  nitric oxide.   A colourless  gas, with-
 out action upon vegetable colours ; its specific gravity is
 1 -0390; it  extinguishes combustion, absorbs oxygen
 with extreme avidity, deeply reddens litmus, and passes
 to the state  of nitrous acid.  Heat and electricity decom-
 pose this oxide ; no combustible body has action upon it at
the ordinary temperature, but  at a red heat many com-
bustibles take its oxygen and set the azote free.  Phos-
phorus transforms it into phosphoric acid  and phosphu-
retted azote.  Chlorine has no  action upon it when the
gases are very dry, otherwise nitrous and muriatic acids
 will be formed.  Iodine and azote do not   combine with
 it.  Burning sulphur plunged in this gas is immediately
extinguished.  Cold water  dissolves one twentieth part
 of its volume ; boiling water does not dissolve  an atom.
It is always  a product of art; in order to prepare it, pour
into a flask containing copper filings, some nitric acid, and
fit to the flask a bent tube with one end placed in the cistern
in a manner  suitable for obtaining the gas.  The nitric acid
 decomposes  in part, to oxidate the metal, while the portion
not decomposed dissolves the oxide formed ; the deutoxide
 of azote set free, disengages in the state of  gas  which 
O  X I
311
passes into the receiver.  The first portions of the gas
should be suffered to escape on account of the atmosphe-
ric air contained in the retort.  In weight, it consists of
100 of azote, 112-98 of oxygen.  It was discovered by
Hales.
   Oxide of Azote  (Proto.)  Protoxide  of Nitrogen.
Nitrous oxide.   A colourless gas, inodorous, of a sugared
taste, specific gravity 1-5273.   This gas is  not perma-
nent.   Faraday  succeeded in  liquefying it with  a very
heavy pressure.   Caloric and the electric fluid decom-
pose it into azote and the deutoxide of azote.  One  of its
essential properties is that of rekindling combustion like
oxygen gas; this is owing to the great facility with which
combustible  bodies decompose it.   This  gas has been
called oxidated  azote, dephlogisticated nitrous gas.   The
English  chemists some years  since announced that it
possessed the singular property of exciting in all persons
the most  pleasurable  and  delightful sensations.   Vau-
quelin,  Gay-Lussac, and Thenard repeated the experi-
ment,  but instead  of finding  it uniformly exhilarating.
they  discovered  that by inhaling it, serious accidents,
such as vertigoes, syncopes, dec.  were  caused.*   The
protoxide of azote  does not exist in nature, it is easily
procured by decomposing at a mild heat, the nitrate of
ammonia ;  the salt is decomposed,  part of  the oxygen
of the acid  unites to the  hydrogen  of the ammonia,
forming water ;  the nitric  acid being thus by the loss of
oxygen  reduced to nit»us gas,  (deutoxide of azote,) it
unites to the azote  of the ammonia, and forms the protox-
ide of azote-  This gas was discovered by  Priestly in
1772 ;  and since then its  properties have been investi-
gated by Davy,  Vauquelin, Gay-Lussac, Thenard,  and
Faraday.

  * The French chemists could not have read with attention the account given
by Sir H. Davy, of the various effects of this gas, as he expressly states, that ii
tamo cases they were disagreeable and painful.
                          27* 
318
O  X 1
  Oxide of Barium (Deuto.)  (Deutoxide de Barium.
Of a  greenish  gray colour, alkaline, having little taste.
Exposed to the  air, it disengages oxygen and attracts car-
bonic acid ; submitted to a high heat it loses a portion of
oxygen, and is  brought to the  state of a protoxide.  All
simple non-metallic bodies transform it at a high tempera-
ture to the protoxide of barium-   Liquid chlorine decom-
poses it cold, disengaging oxygen and producing the chlo
ride  of barium;  heated  strongly  with  hydrogen gas it
disengages light and heat, producing, by the formation ot
water, a hydrate of the protoxide.  Cold water has little
action upon the deutoxide of barium ; boiling water dis-
engages a part of its oxygen.   It does  not exist in na
ture ; it is prepared by heating the protoxide with hydro-
gen;  the  operation should be performed over mercury.
It may  be obtained from the hydrate by pouring a con-
centrated solution of barytes  into acid oxygenated wa-
ter.   It deposits brilliant  spangles, but  these cannot  be
dried without disengaging oxygen gas.   Thenard, who
has paid  much attention to the  properties of this oxide,
states that it contains double  the  quantity of oxygen  to
that contained  by the protoxide.
  Oxide  of Barium  (Proto.)  (Protoxide de Barium.)
Barytes.  It  is of a grayish white, caustic, and  stronglj
greens  the infusion of violets.   Exposed  to the air, it
attracts moisture and carbonic acid.  When heated with
oxygen gas, it absorbs  it and  transforms  itself into a
deutoxide ; if submitted  to th««action of fire in contact
with the air,  it  is converted into a deutoxide and proto-
carbonate; by a degree of heat more  elevated, it  de-
composes, and only the proto-carbonate of barytes is  ob-
tained.    Barytes is not found in nature except in combi-
nation with carbonic  and  sulphuric acids.   The know-
ledge of  this substance  is  due to a  triple discovery of
Scheele ; this  pharmacian discovered in one experiment.
 muriatic  acid,  (chlorine,) manganese, and barytes: Fa 
0  X I
319
i aday and Vauquelin first obtained  barium in a state of
purity;  -it was regarded  as a simple  body until Davy
made the discovery of the alkaline metals.   The  pro-
toxide of barium is  composed of 11 -669 of oxygen and
100 of barium.   It is employed only in the laboratories
of chemists.
  Oxide of Bismuth.   (Oxide de Bismuth.)  Is yellow-
ish, without action upon  air and  oxygen  gas; it fuses
when submitted  to red heat.  . Some mineralogists think
that it exists  on *the surface  of native bismuth.  It is
easily procured  by boiling with a solution  of potash or
soda,  the sub-nitrate of bismuth;  in order to  obtain it
pure the precipitate should be washed, filtered, and cal-
cined.   It may also be prepared by heating bismuth in
contact  with the  air.  It  consists of 100 of metal, and
11*275 of oxygen.
  Oxide of  Cadmium.  {Oxide de Cadmium.)   Accord-
ing  to  Stromeyer, the  oxide of cadmium ;  is sometimes
yellow, sometimes brownish, and even black.   I.i the state
of a hydrate it is always colourless, it is undecomposable
at the highest  heat, is  easily reducible by  charcoal."  It
exists in nature, combined with carbonic acid and silex,
in zinc ores.  This oxide  is obtained by heating the me-
tal in contact  with the  air; by potash is  precipitated a
soluble salt of cadmium.  It is composed of 100 parts of
metal, and 14-352 of oxygen.
  Oxide of Calcium (Proto.)  (Protoxide de Calcium.)
Lime.   (Chaux.)  It is a white substance, of  a  caustic
taste, greens the infusion of violets ; its specific  gravity is
2-3, it is commonly called quick lime.  Submitted to the
greatest heat, it undergoes no  alteration ; exposed to the
air  it attracts  humidity and carbonic acid,  is  reduced to
powder and passes to the state  of a sub-carbonate; b\
the aid  of heat it combines with phosphorus  and iodine.
Sulphur, selenium, and chlorine effect its decomposition.
 Lime dissolves in 700 times its weight of water; it ab 
320
O  X I
 sorbs this fluid with great avidity, forming with it a true
 hydrate, and presenting  many remarkable  phenomena:
 when upon a piece of lime some  drops of water arc
 poured, the water is rapidly absorbed without the lime ap.
 poaring to be moistened ; it soon with a hissing noise ex-
 foliates, the vapour of the water passes off,  and the lime
 crumbles to powder; it eliminates so much  caloric as to
 set fire to tinder ; this process is called slaking lime ; one
 part of the water passes to  a solid  state,  leaves its calo-
 ric, and reduces to vapour the part'of the water which is
 still liquid.   This production of.vapour is sometimes ac-
 companied  with  light.   Lime has been known from the
 highest antiquity ; it is extensively diffused in nature, but
 never found in a state  of  purity, being  combined with
 carbonic, sulphuric, and phosphoric acids; with the firs
 (t constitutes  marble, chalk, building stones, dec.7 with
 the second it forms plaster or gypsum ; and with the third
 exists in the bones of all  animals.   The carbonate is
 usually employed for obtaining lime ; the carbonic acid
 is driven off by heat, and lime in a tolerably pure state is
 obtained.  The calcining of limestone for commerce is
 carried on in a  large  way in  lime-kilns in countries
 which furnish an abundance of carbonate of lime.   For
 use in the  laboratory, lime  is obtained by  introducing
 powdered marble or oyster shells (which are a very pure
 carbonate of lime) into a porcelain or earthen retort, and
 subjecting it to heat; the carbonic  acid passes off, and
 iime remains in the retort.   Too great a degree of heat
 should be avoided, otherwise the carbonate oflime which
 contains silex would undergo a kind of vitrification which
 would change its properties; it is then said  to be burnt.
 The lime is known to be sufficiently calcined when it no
 longer effervesces with acids.  The protoxide of calcium
 ls  composed of 100 of a metal, (called  calcium,} and
39-068 of oxygen.   It was  regarded as a simple body
 until the discovery of potassium.   Lime is of great uti 
O  X I
321
hty ;  it is employed in the manufacture of soap, for the
construction of buildings, for the preparation  of ammo-
nia, and for manuring land ; it is an important reagent in
the laboratory of chemists; it is also used by the physi-
cian in some medicinal preparations.
   Oxide of Carron.   (Oxide  de Carbone.)  An inodo-
rous, invisible,  insipid gas,  extinguishing combustion:
when inhaled by the lungs it is  fatal to  animal  life.  Its
specific gravity is 0-9727.  This  gas supports the inten-
sity of  the heat and the action of the voltaic pile without
being  decomposed; it  has no  action upon  atmospheric
air and oxygen gas.  Among combustible bodies, chlo-
rine alone acts  upon it; when a very dry mixture of
equal parts of chlorine and the  oxide gas  of carbon are
exposed in a flask to the influence of the  solar rays, the
volume  con'racts half its  bulk, giving rise to  an  acid
known by the name of chloroxi-carbonic gas, (also called
chloro-carbonous acid, or carbo-muriatic acid, phosgene gas,
dec.)    1 he oxide  gas of carbon  is  inflammable;  if
brought into contact with a lighted  taper, it burns with
flame and  is changed into carbonic acid ;  it is almost
insoluble in water.  This gas is procured by introducing
at a high temperature carbonic acid into a  porcelain tube
filled with dry charcoal; it may also be procured by de-
composing by heat in a retort the oxalate of- lead or zinc ;
in both  these cases it  is necessary to pass  the  gaseous
product  across a solution  of wax or potash in order to
absorb the  carbonic acid which it always contains.   It is
formed  of one volume of carbon and \\ volume of oxy-
gen, or in weight of 100 of oxygen" and 76-56 of carbon.
It was discovered nearly at the  same time  by Mr Cruik-
sha k in England, and  by MM. Clement  and  Desormes
in France.
   Oxide Caseous.   {Oxide Caseux.)  A name given by
M. Proust to a white, insipid, inodorous, and spongy sub-
stance, which is  obtained from caseum or fermented glu 
322
O  X I
ten;  this oxide exists abundantly  in  old  cheese ;  h  i-
obtained from its combination by successively using recti-
fied alcohol, diluted alcohol, and water.
  Oxide of Cerium.*  (Oxide  de Cerium.)   White, al-
most infusible ; submitted to the action of  fire, at a high
temperature, it passes to the state of a  deutoxide.  It has
not yet been found in nature; it  is procured easily by de-
composing the chloride of cerium by a solution of soda,
or potash; the precipitate is washed and filtered.  It is
composed of  100 of cerium, and 17-41 of oxygen.   The
deutoxide is of a chestnut brown ; it is without action upon
atmospheric air and oxygen gas.  It exists in some cop-
per mines of Sweden, constituting  what some mineralo-
gists called cerite.  It may be obtained by  suitably heat-
ing the  protoxide, or  decomposing  the deuto-nitrate  by
dissolving it in nitro-muriatic acid.  The filtered solution
being neutralized with pure potassa, it is precipitated by
tartrate of potassa.   Hisinger, Berzelius, Vauquelin, and
Laugier  have all investigated the properties of these ox-
ides.  The last of these chemists has published an excel-
lent process for separating them entirely from the oxide
of iron.
  Oxide of Chlorine.  (Oxide de Chhre.)   A yellow-
ish  green gas, of an odour not disagreeable, and having
no analogy to that of chlorine.  It  does not  redden lit-
mus, but destroys its colour.   According  to Faraday it
may be  liquefied.  Exposed to a high  temperature it be-
comes luminous, exploding with such violence as to break
the vessel which contains it; phosphorus introduced into
this gas produces similar effects.  Water dissolves it rea-
dily, and acquires a corrosive  and disagreeable taste.
This  oxide was discovered by  Davy  in 1815, and has
since been investigated by Count Stadion.   Its prepara-
tion is attended with danger on account  of its liability to

  •* The planet Ceres was discovered about  the same time  as this ojidc, hnnr.
rhe name 
O  X I
323
explosion.  Thenard advises, in order to  prevent  such
accidents, to prepare it as follows : let  a paste, made of
the pulverized chlorate of potash and  of diluted sulphu-
ric acid, be introduced into a glass  tube hermetically
sealed at one end; place it vertically and fit to it a little
bent tube, heat it very slowly in a sand-bath; the disen-
gaging gas must be collected over mercury ; it is a mix-
ture of one twentieth of oxygen and one fortieth of chlo-
rine.  The oxide  of chlorine is in volume composed of
1  of oxygen and l£ of chlorine  condensed into one.
Chevreul called it the chloride of oxygen, (chlorure d'oxi-
gcne.)   By treating  the chlorate of potash with  hydro-
chloric acid, an oxide of chlorine has been obtained,
which has been called euchlorine and chlorous acid;  but
according to  Davy and  Thenard it  appears to be  but  a
simple mixture of the preceding oxide gas with a certain
quantity of chlorine.
  Oxide of Chrome  (Deuto.)   (Deutoxide de Chrome.)
This oxide is brown,  pulverulent,  brilliant, insoluble in
water and in  acids.   It is obtained by dissolving in nitric
acid the  protoxide to the state  of a hydrate, and evapo-
rating the solution until it no longer disengages nitrous
vapours.  According  to Berzelius it is formed of 100 of
metal and 56-84 of oxygen.
  Oxide of Chrome  (Proto.)   (Protoxide de Chrome.)
Green,  pulverulent, infusible  and undecomposable by the
heat of the furnace, without action upon oxygen gas at
any temperature, insoluble in water.  Thenard and Gay-
Lussac  obtained, by beating  the  oxide of chrome  with
part of its weight of potassium or sodium, a brown mass
which  on being cooled  burnt  spontaneously in the air,
transforming itself into  a  chromate of potash or soda.
This oxide is sometimes found on the surface of chro-
mated  lead;  it is this which causes the green colour of
the emerald  and many  magnesian rocks.  In order to
prepare it, a  very common method  is  to ^decompose the 
324
O  X I
chromate of mercury at a  high  temperature ;  the met
cury is disengaged and the oxide  of chrome remains
fixed.  The oxide of chrome  was  discovered by Vau-
quelin.  It  is composed of 100 of chrome and 42-633 ol
oxygen.  This  oxide  is employed in the arts ; it is this
which gives the fine green colour to porcelain, and which
colours the artificial stones  made to  imitate the emerald.
It is used in chemistry in order to extract the metal.
  Oxide of Cobalt (Deuto.) {Deutoxidede Cobalt.) Black,
insoluble in water and the acids.  Exposed to a high tem-
perature it abandons a portion of its oxygen.  It is found
in nature on the surface  of arsenical cobalt.   It is ob-
tained by decomposing the nitrate of cobalt with heat, or
by exposing the protoxide to a red heat.  According to
Proust, it is formed of 100 of metal and 26  of oxygen,
and according to Berzelius, of 40-647 of oxygen.
  Oxide of Cobalt   (PrOto.)  (Protoxide de Cobalt.)
Gray, almost infusible, blue when in  the state of a hy-
drate.  It absorbs oxygen easily, becoming a peroxide.
It exists in  nature  only in combination.   It  is  procured
by decomposing the  chloride of cobalt  by a solution of
potash or soda ;  it combines with acids and forms  rose-
coloured solutions.  According to Berzelius, it contains
100 of metal to  27-097 of oxygen.   The oxides of cobalt
are employed in giving a blue colour  to glass and enamel;
it is the base of Thenard's blue (cobalt blue).
  Oxide of Columbium.   See Columbic Acid.
  Oxide of Copper (Proto.) (Protoxide de Cuivre.) Au
orange red, fusible  into a reddish mass, changes to a
deutoxide  at  a  heat little elevated.   It exists in nature.
is frequently found either in crystals or in capillary veins
in deposites of sulphuretted  copper.  It is obtained by de-
composing the chloride of copper by potash  or soda.  It
ts formed of 100 of metal and 12-636 of oxygen.
  Oxide of Copper   (Trito.)   {Tritoxide de Cuivre,)
Thenard obtained this oxide by means  of oxygenated 
O  X I
325
 water and the nitrate  of copper.   See his Treatise  on
 Chemistry.
   Oxide Cystic.  (Oxide Cystique.)  It is found in some
 animal substances; it  may  be found described in the
 Chemical Treatise of Dr. Wollaston, and has also been
 noticed by Lassaigne.
   Oxide of Glucinum, or Glucina.   (Oxide de Gluci-
 nium, ou Glucine.)  (The name is derived  from the Greek
 gluteus, sweet, because it gives that taste to the salts which
 it forms.)  White, insipid, without  action  upon simple
 bodies.  Exposed to a  strong heat, it melts to a white
 enamel.   It  is insoluble in water, attracts carbonic acid
 from the air, and  possesses the property of forming su-
 gared salts if they are soluble.   This substance has yet
 been found only in the emerald, the beryl, (aigue-marine)
 and the euclase.   Glucina is extracted from the  emerald
 by treating the mineral successively with potash  and
hydro-chloric acid, evaporating the  residue to dryness,
 diluting it with water and then filtering it; into the  fil-
 tered liquor is poured an excess of the sub-carbonate of
 ammonia, it  is filtered a second  time  and then boiled  :
 the carbonate of glucina which was rendered  soluble by
 the excess of the sub-carbonate of ammonia is deposited  ;
 it is  washed and strongly calcined in order to disengage
 the carbonic acid.   Glucina  was discovered by Vauque-
 lin, and regarded  as a simple substance, until the disco-
 very of the alkaline metals.
   Oxide of Gold  (Deuto.)   (Oxide d'Or deuto.)  It is
 reddish yellow when in the state of a hydrate,  and brown
 when  it is dry.  It  may easily be reduced by heat and
 by the voltaic pile ;  it  has no action upon  oxygen, dis-
 solves with difficulty even in the strongest acids ; on the
 contrary it dissolves very well in alkalies, and according
 to Pelletier acts with them  the part of an acid.   That
 chemist gives the  following process  for obtaining it: a
 solution of the  chloride of gold is boiled with magnesia-;
                         28 
326
0  X 1
 the oxide precipitates  and takes with it a portion of the
 magnesia ;  the precipitate is boiled  with diluted nitric
 acid which dissolves the magnesia without attacking the
 oxide of gold,  which remains in the  state of a hydrate;
 it is collected on  a filter and dried under the receiver of
 the pneumatic  cistern.  It is by Berzelius said to consist
 of 100 of gold  and 12-077 of oxygen.
   Ostide of Gold (Proto.)  (Protoxide d'Or.)  Berzelius
 admits an oxide of gold which according to him contains
 but one third of the oxygen of the deutoxide of gold ; hut
 if this oxide  exists, it  is decomposed with the greatest
 facility by light.  It remains  in combination with  hydro-
 chloric acid when the hydro-chlorate of gold (muriate) is
 evaporated until chlorine can no longer be disengaged.
   Oxide of Hydrogen (Deuto.)  See Oxygenated  Wa-
 ter.
   Oxide of Hydrogen (Proto.)  (Protoxide d'Hydro-
 gdne.)   The  scientific  name of water ; it is noi however
 in use; the  common  name  being  consecrated  by the
 highest antiquity, it would appear ridiculous to attempt
 to substitute its chemical name.
   Oxide of  Iridium.   (Oxide d'Iridium.)  This oxide
 is not known, because that iridium cannot be acted upon
 by acids and  oxygen gas.  It can be  oxidated only by
 calcining it strongly with the nitrate of potash; but it is
 impossible  to separate it wholly from  the alkali.  The
 salts of iridium being sometimes red and sometimes blue,
 Vauquelin  supposes that  there  may be many oxides of
 this metal.
   Oxide of Iron (Deuto.)  (Deutoxide de Fer.)  Black
 and magnetic ;  if heated in close vessels, it fuses without
being decomposed ; but in the air, unless the temperature
be too elevated, it passes to the  state  of  a tritoxide.
Gay-Lussac,  in investigating  the properties of this  sub-
stance, observed the following remarkable phenomenon,
viz. that this oxide, when heated to redness in a  porce- 
O  X 1
32?
 lain tube with hvdrogen gas, formed water, and the metal
 was reduced.  This circumstance is the more surprising
 as  fire  decomposes  water at the  same temperature.
 According to Vauquelin, concentrated nitric acid  carries
 it to the  highest point of oxidation, dissolving it, and pro-
 ducing a colourless trito-nitrate.  Sulphuric acid dissolves
 without  changing  it, and  forms  a deuto-sulphate which
 varies in colour with the quantity  of oxide dissolved.
 This oxide is soluble  in a great excess of ammonia. The
 deutoxide of iron is found abundantly iia nature.  It  is
 sometimes crystallized in octoedrons or dodecahedrons;
 as that found in Sweden  and the island  of Corsica.   It
 exists also in the form of sand in France, Italy, dec, or in
 compact masses, as in Bohemia, Siberia, Norway, and
 many other places.
  The deutoxide of iron  constitutes the loadstone,  or
magnet (aimant) ; it is obtained  by exposing iron filings
in a  porcelain  tube to a current of steam as long as any
hydrogen comes over. It is employed in medicine under
the  name of ethiops martial;  this maybe obtained by
making with pure water a paste of iron filings, putting the
paste into a shallow earthen pan, and often  stirring  it,
taking care to have the surface  kept moist.  The mass
heats, disengages from the water hydrogen gas ; the iron
uniting to the oxygen of the water becomes a deutoxide.
A more expeditious method is to add about  one eighth ,
part nitric acid to the water used in making the paste ;
this causes a more  sudden increase of temperature, and
the  operation is completed in a few hours.  By washing
the  deutoxide with several waters, the ethiops is obtained
perfectly pure.  According to  Gay-Lussac, it is  formed
of 100 of iron and 38 of oxygen.   Dulong and Berzelius
think that it is but a combination of the protoxide with the
tritoxide, and that the one performs the part of  an acid
with respect to the other. 
328
O  X  I
  Oxide of Iron (Proto.)   {Protoxide de Fer.)    Tin-
oxide is known only in the state of a hydrate; it is then
white.  It cannot  be dried without passing to a higher
state of oxidation ;  it becomes greenish on being brought
in contact with  the air, then takes a  reddish  tinge  by
absorbing oxygen and carbonic acid.  It  is insoluble in
water, and exists  in  nature only  in combination with
silex  and  sulphuric acid.   The  protoxide  of iron  is
obtained by decomposing a  solution of the  sulphate of
iron with potash or soda;  the precipitate  is washed with
water which has been deprived of air ; it is then preserved
in flasks of water  closely stopped.   According to Gay-
Lussac, it is composed of 100 of iron and 28-3 of oxygen.
It was discovered by Thenard and Chenevix.
  Oxide of Iron (Trito.)  (Tritoxide  de Fer.)   Violet
red, more fusible than  iron, not decomposable  by heat,
not magnetic, insoluble in water.   It absorbs  carbonic
acid from the air  at the ordinary temperature.   The
tritoxide of iron exists in nature in great quantities ; as in
the hematites, oligiste iron,  eagle-stone  or (Btite* brown
oxide of iron,  dec, whi«h are almost entirely constituted
of  this substance.   It  is found in various countries;  as
Norway,  Sweden,  Siberia,  the  island  of Elba, various
parts  of North America, dec.  It is the tritoxide of iron
which colours the different kinds of clays known  under
the names of  red ochre, yellow ochre, clay of Tripoli, bole
of Armenia, terra sigillata, dec   This oxide was formerly
known in medicine  under the name of  colcothar; it may
be obtained, 1st, by decomposing the nitrate of iron with
heat;  2d, by precipitating .a trito salt of  iron by potash
or soda; 3d, by decomposing the  sulphate of iron at a
high heat, in order to disengage the sulphuric acid.

  * This is found in nodules of various sizes, from that of a small nut to the
iize of a man's head  The ancients supposed that the eagles were in the habit
of transporting these balls to their nests; they therefore gave them the name of
'•agle-stones.  The mincralogical name in English is Nodular Argillaceous
Oride of Iron. 
0  X I
329
   Oxide  of Lead  (Proto.)   (Protoxide  de Plomb.)
 Litharge.   Yellow ;  it easily fuses, crystallizes in yellow-
 scales on cooling; it has no  action upon  oxygen gas at
 the ordinary temperature ;  but it attracts a little carbonic
 acid from  the air; at a heat  little elevated it passes to a
 higher degree of oxidation.   It exists in nature only in
 combination with  acids. It is prepared in laboratories by
 heating to redness the red oxide of lead, (minium,) or by
 decomposing the proto-nitrate of lead in a platina cruci-
 ble.  This acid is an article of considerable  importance
 in commerce ; it is obtained  in the working  of argenti-
 ferous (silver-bearing) lead ores.   The alloy of lead and
 silver is calcined in the open air ; the silver remains pure,
 and all  the lead  oxidates.  The  protoxide  of  lead is
 stated by Berzelius to consist of 100 of metal  and 7-73 of
 oxygen.   It is much employed in the arts ; it is used in
 preparing white lead,  Naples yellow, the acetate of  lead,
 dec, and also for medicinal preparations.
  Oxide of Lead  (Per.)    (Oxide  Puce. Per-oxide de
 Plomb.)   Brown,  insoluble in acids,  passes  to the  state
 of a protoxide at a red heat.   It inflames when triturated
 with sulphur, forming a sulphuret of lead and disengaging
 sulphurous acid.   It has no action upon the air or  oxy-
 gen gas.   It is not found in  nature, but is obtained by
 bringing the red oxide of lead in contact with concen-
 trated  nitric acid.  One portion  of the oxygen  of the
 oxide of lead unites with another part of the  same oxide
 forming the protoxide ; this protoxide is dissolved in the
 nitric acid; the precipitate is washed and carefully pre-
 served from contact with the  air.   It is said to consist of
 100 of metal and 15*474 of oxygen.   It is not used in
 the arts or in medicine.
  Oxide of Lead  (Sub.)   (Oxide de Plomb sous.)  Ash
 coloured.  It is said by Berzelius to be formed by expos-
ing lead at a small  increase of temperature to the air.
                         28* 
330
0  X I
This oxide, according to Dulong, may be obtained b\
calcining the oxalate of lead.
  Oxide of Lead  (Deuto.)  (Deutoxide de Plomb.)  A
lively red ;  it is unalterable by the air, is insoluble in acids.
In contact  with  nitric acid one portion  deoxidates  and
becomes soluble, while the other gains oxygen  and pre-
cipitates in the form of an insoluble peroxide.   At a red
heat this oxide  decomposes into oxygen and  a yellow
protoxide.   Some  mineralogists believe that it exists in
nature with sulphuretted  lead.  It is prepared in the arts
by calcining lead  in large  reverberatory furnaces; the
lead fuses and is covered with a crust of yellow oxide of
lead, known  by the  name of massicot; this crust is re-
moved as well as others which are formed.   When all
the  lead is changed to  massicot, the  calcination is still
continued  for a time, in order to oxidate the lead which
might still  be in a metallic state; the oxide is then with-
drawn from the  furnace  and cooled  by throwing upon it
cold water.  This oxide is known in commerce as minium,
or red lead,  (mine de plomb rouge).  It sometimes con-
tains the oxide of copper and the protoxide of lead ;  these
may be  separated by leaving the oxide for some days in
water a little acidified  by vinegar; the two  oxides dis-
solve, while the deutoxide of lead remains without being
 affected.  The  deutoxide of lead  is  formed  of 100 of
 metal and 11-587 of oxygen.  It is used in potteries for
 glazing, it is also  employed in the manufacture of crys-
 tal and in oil painting.   It may  be but a combination of
 the protoxide and the tritoxide.
   Oxide of Lithium.   (Oxide de Lithium, ou Lithine.)
 Lithia.  (From the Greek lithos, a stone.)  White, very
 caustic, inodorous,  greens the infusion of violets ; and
 strongly attracts  carbonic acid  from the air, changing
 itself to a sub-carbonate; it is  soluble in 100 times its
 weight of water.  This  substance is analogous to potash
 and soda; it is  much more soluble in water than barytes 
0  X 1
331
or strontian.   Combined with acids it forms neutral salts.
Its  tendency to attack platina is such, that according  to
Berzelius, this metal can  always be  depended upon  to
detect traces of  lithia in any  mineral.   This  savant
directs to take a piece  of mineral of  the size of a pin's
head, by means of a blow-pipe to heat it with an excess
of soda upon a thin  leaf of platina ;  the mineral is  de-
composed, the soda expels the  oxide  of lithium  from its
combination, and the excess of soda, being liquid  at this
temperature, spreads over the leaf of platina surrounding
the  decomposed  mass.   Around  this  melted alkaline
mass the platina takes a deeper colour, forming a circle,
darker  and  larger in  proportion as the mineral takes a
greater portion of lithia.  The platina  resumes its me-
tallic lustre on being washed and heated ; oxidation does
not take place without the alkali.
  Lithia has  hitherto  been  found only in  the petalite,
(riphane, green tourmaline, and the rubellite; it exists  in
these but in very small quantities.   The oxide of lithium,
or lithia, may be obtained by strongly calcining, in a pla-
tina crucible, for two hours, a mixture of equal parts of car-
bonate of barytes and of a mineral containing lithia;  the
carbonate of barytes  is decomposed, while the  barytes
uniting to the mineral changes  its nature,  rendering it
liable to be acted upon by  acids.   By the aid of heat the
mass is dissolved in diluted hydro-chloric acid, the hydro-
chlorates which  are formed are  then  dried; the residue
is diluted with water and filtered  in order to  separate the
silex.   The solution contains only the hydro-chlorates of
alumina, barytes,  iron, and lithia;  by sulphuric  acid  all
the barytes  is separated, ammonia is added to  saturate
the excess of acid.  When the liquor is neutral, an excess
of the carbonate of ammonia is introduced ;  this decom.
poses all the salts except the lithia, precipitating them in
the  state  of a carbonate.   The sulphuric acid  decom-
posing the hydro-chlorates; there remains in the liquor 
332
O  X I
 only the sulphate  of lithia, ammonia, and the hydro-
 chlorate of ammonia;  the residue is strongly calcined in
 order to decompose the ammoniacal salts, and the pure
 sulphate of lithia alone remains.   This sulphate is re-
 dissolved in distilled water, and the sulphuric acid being
 saturated by a solution of barytes, precipitates an insolu-
 ble  sulphate of barytes, and the new alkali remains in
 solution  in  the liquor;  this is evaporated  in a retort to
 dryness, in order to prevent the lbhia from absorbing
 carbonic acid  from  the air.   The oxide of lithium is sup-
 posed to-be formed  of 100 of metal and 78-25 of oxygen.
 This new  alkali was  discovered  in 1818  by M. Arf-
 wedson.
   Oxide of Magnesium.  (Oxide de Magnesium.) Mag-
 nesia.  A white, soft  powder, without odour or taste ; it
 greens the sirup of  violets ; its specific gravity, according
 to Kirwan, is 2-3.   It  has no action upon  oxygen  gas
 and  imponderable  fluids; it is  infusible  by  the most
 violent heat, and at  the ordinary temperature, attracts the
 carbonic acid from  the air.   Among combustible bodies,
 chlorine  alone is known  to have any  action  upon this
 earth.
   Magnesia exists  abundantly in  nature,  but always in
 combination with acids or metallic oxides.   It is obtained
 by heating the sub-carbonate of magnesia, until it will no
1 onger effervesce with acids.   It is employed in medicine
 under the name  of calcined magnesia, magnesie calcinee.)
 The oxide of magnesium consists of 100 of  metal  (mag.
nesium,) and 63-159 of oxygen.  It was discovered by
 Frederic Hoffman,  in 1722;  but  Dr. Black first consi-
 dered it as a peculiar substance ; it was afterwards studied
by Margraff and Bergmann, and regarded  as a simple
body until the discovery of potassium, by Davy.
  Oxide of Manganese (Deuto.)  (Deutoxide de man-
 ganese.)  A substance of a reddish  brown colour, redu-
cible by the voltaic  pile, insoluble by water, and not de. 
O  X I
333
 composable by fire.  This oxide  absorbs the oxygen of
 the atmosphere, at the ordinary temperature, particularly
 if the air is humid. In contact with nitric acid, it separates
 into a soluble protoxide, and a peroxide Which is precipi-
 tated.  It exists in nature only in combination with silex.
 It is  obtained by strongly calcining the peroxide.   Ac
 cording to Arfwedson, it consists of 100 of metal,  and
 37-475 of oxygen.
   Oxide of Manganese  (Proto.) (Protoxide de man-
 ganese.)  White in the state of a hydrate;  green when
 it is dry ; it readily attracts  the oxygen of  the  air,  and
 becomes brown:  it is reducible by the  voltaic pile,  and
 undecomposable  by fire.  According to Clarke, it  has
 been reduced by losing its oxygen, by means of Brooke's
 blow-pipe.   It is obtained by precipitating a  proto-salt of
 manganese with potash or soda.   It is preserved like the
 protoxide of iron.   It is  composed of 100 of metal,  and
 28-1077 of oxygen.
  Oxide of Manganese  (Trito or  Per.)   Blackish
 brown, of a metallic appearance when in crystals, without
 action upon oxygen gas, reducible by the voltaic pile, in-
soluble in water.   Heated strongly in a porcelain tube
 with phosphorus, it changes  into a phosphate of manga-
 nese ;  sulphur in the same situation changes  it to a sul-
 phuret, disengaging sulphurous acid.  The  peroxide of
 manganese exists in nature in great quantities ; some-
 times in  brilliant needles, as  in sulphuretted antimony;
 sometimes  in stalactites, but  ofener in masses which
 have  a metallic  appearance,  sometimes varying  from
 brown to black.   It is  only pure when crystallized; con-
 siderable deposites of it are found both in primitive and
 secondary countries ; it exists in the Vosges mountains,
 the Cevennes, and the Hartz, in Saxony, Siberia, and
 various parts of North  America.   It can be  prepared in
laboratories  by decomposing  with heat the nitrate of
 manganese.   It is composed of 100 of manganese, and 
334
O  X I
56-215  of oxygen.  It  is employed in the arts for tin
preparation of chlorine,  and in the laboratories  of che-
mists, for the obtaining of oxygen gas.  Arfwedson admits
four oxides of manganese ;  be designates by the name of
tritoxide, one which  is  intermediate,  between the deu-
toxide and the oxide above described ;  he considers  it
as composed of 100 of metal, and 42-016 ofoxvgen; but
this oxide  is not  by most chemists supposed to have an
existence.
  Oxide of  Mercury   (Deuto.)  (Deutoxide de  Mer-
cure.)   Red Precipitate.  Of a lively red, yellow when in
the state of a hydrate.   This oxide is reducible at a red
heat; it has no action upon atmospheric air and oxygen
gas.  At a temperature  little elevated, it yields its oxygen
to most combustible bodies.   It is always a product of
art.  It is obtained by dissolving mercury in nitric acid.
and afterward decomposing the mercurial salt  by heat;
the nitric  acid  is decomposed into oxygen and nitrous
acid which is disengaged.   The deutoxide of mercur)
remains in the  form of violet red spangles,  which on
cooling  become  orange red.   The operation  is  com-
pleted when nitrous vapours, which can always be known
by their odour,  are no  longer visible.  This  deutoxide
can  also be obtained by  decomposing the per-chloride of
mercury by a solution of soda or  potash, and washing
and  drying the precipitate ; or by beating  mercury in  a
matrass for fifteen or twenty hours, at a temperature near
to boiling and in contact with the air.  The oxide thus
obtained, was formerly called precipite per se.  The deu-
toxide, or  red oxide of  mercury, on which alcohol has
been burnt, was called arcanum corallinum.   This  oxide
is formed of 100 of mercury, and 7-9 of oxygen.   It is
only used  in medicine, and the laboratories of chemists.
  Oxide of Mercury  (Proto.)  (Protoxide  de  Mer-
cure.)   This  oxide exists only in  combination.   Man)
chemists have considered the black precipitate which is 
0  X I
335
obtained by decomposing the proto-nitrate'of mercury by
a solution of soda or  potash, as  a protoxide of mercury.
According to M. Guibourt, it was not proper to take for a
protoxide, the black precipitate obtained by decomposing
the  proto-nitrate of mercury  by a solution  of soda or
potash;  he thinks this pretended protoxide is but a mix.
ture of deutoxide and subdivided mercury ; for by rubbing
it  between two  hard  bodies, little globules of metallic
mercury appear.
   Oxide of Molybdenum  (Deuto.)  (Deutoxide  de
Molybdene.)   Blue oxide.   As  this oxide possesses all
the properties of acids, in a certain degree, it has been
described under the article Acid Molybdous.'   Richter
called it blue carmine.  It .was used in painting before the
discovery of Thenard's blue.   (Cobalt blue.)
   Oxide of Molybdenum  (Proto.)  (Protoxide de Mo-
lybdene.)  Of  a  reddish  brown  and crystalline appear-
ance.  It does not exist in  nature.  It was obtained by
Bucholz, by heating  strongly, in a crucible covered with
powdered charcoal, pulverized molybdate  of ammonia.
ft contains 100 of metal and 16-755 of oxygen.
  Oxide of Nickel   (Deuto.)   '(Deutoxide de Nickel.)
This  oxide  was  obtained  by Thenard  when  treating
nickel with oxygenated water and potash.  This chemist
not having analyzed  the oxide, considered its existence
somewhat doubtful.   See Thenard's Treatise on  Che-
mistry.
  Oxide of Nickel   (Proto.)  Of a deep brown when
dry, and of an  apple-green when in the state of a hydrate.
The  protoxide of nickel is almost infusible; it is reduci-
ble by hydrogen gas aided by heat;  it has no action upon
atmospheric air  and oxygen gas.  It is easily  obtained
by decomposing a proto-salt of nickel by potash or soda;
it precipitates in  greenish flakes.   According to Berze-
lius,  it is composed of 100 of metal and 27-049 of oxy- 
336
O  X I
 gen;  but  LasS&igne states the quantity of oxygen to be
 only 20.
   Oxide Nitrous.   (Oxide Nitreux.)   See Deutoxide of
 Azote.
   Oxide of Osmium.  (Oxide d'Osmium.)   White, of an
 odour similar to that of horse-radish ;  caustic, melts and
 volatilizes easily, is  reducible by  heat; it has no  action
 upon  oxygen  gas,  combines difficultly with acids;  it
 dissolves well  with  alkalies, exhibiting in  combination
 with them phenomena analogous to those presented by
 the oxide of gold.   It does not exist in nature ; it  is ob-
 tained by heating a mixture of osmium and the nitrate of
 potash in a retort, to the neck of which is fixed a small
 receiver, into which  the oxide of  osmium in the form of
 an oily liquid passes ; this on cooling becomes solid.  It
 is not used in medicine or the arts.
   Oxide of Palladium.   (Oxide de Palladium.)  Red-
 dish brown when in the state of a hydrate, black when it
 is dry.  It is always a product of art.  It is  obtained by
 pouring into a solution of the chloride of palladium an
 excess of potash, heating, washing, and drying the pre-
 cipitate.   It was discovered by Vauquelin ; according to
 Berzelius,  it consists of 100 of metal and 14-207 of
 oxygen.
   Oxides of Phosphorus. ( Oxides de Phosphore.)  Some
 chemists admit two oxides of phosphorus ; the first,  which
 they call white oxide, (oxide blanc,) is  formed whenever
 phosphorus remains  some time in water in contact with
 the air.  The cylinders  of phosphorus  become covered
with a  whitish crust,  of an  odour similar to  phosphorus,
but less inflammable.  The other oxide, which chemists
call red oxide,  (oxide rouge,) is  the residue obtained on
distilling phosphorus which  has been several times used
for the analysis of atmospheric air. Phosphorus  burnt
rapidly in the  air produces  a similar  substance.   This
appears to differ little from the preceding except in  co- 
O  X I
331
  lour.  Thenard considers these two oxides identical, ex-
  cept that the first is in the hydrated state.
    Oxide of Platina (Deuto.)  (Deutoxide de Platine.)
  Black, insipid, reducible by the pile and by heat, decom-
  posable by most of the combustible bodies.  This oxide
  is obtained  by pouring an excess of caustic soda into a
  solution of the chloride of platina; it is made to boil, one
  part of the oxide precipitates, and the other by means of
  the alkali remains dissolved in the liquor, till after many
  washings it is obtained pure.   According to Berzelius, it
  is composed of 100 of platina and 16.45 of oxygen.
    Oxide  of Platina (Proto.)  (Protoxide de Platine.)
  It resembles the protoxide of gold.   According to Ber-
  zelius, it remains in combination with hydro-chloric acid
  when the hydro-chlorate of platina is evaporated, until it
 no longer engages chlorine.  Chenevix also admits this
 oxide.
   Oxide of Pluranium.   It appears  in  long prismatic
 rose-coloured crystals, and is  obtained from the  native
 platina of Russia.  After this platina has been subjected
 to the process for obtaining osmium, if the residue is al-
 lowed to rest for 24 hours, these crystals appear.
   Oxide of Potassium  (Deuto.)  (Deutoxide de Potas-
 slum.)  Yellowish green, very caustic.  It strongly greens
 the sirup of violets.   All simple bodies except nitrogen
 take  from it a  portion of  its  oxygen, reducing it  to a
 protoxide.   Water decomposes it.  It does not exist in
 nature ; it is obtained by heating under a bell-glass a
 small piece of potassium with an excess of oxygen gas •
 the operation must  be performed over mercury.   This
 oxide consists of 100 of potassium and 60 of oxygen.  It
 was discovered by Gay-Lussac and Thenard.
  Oxide  of Potassium   (Proto.)  (Potasse.)  Potash.
 So called  from the pots or vessels in which it  was first
made.  When pure  it is white, caustic, very alkaline •
of a specific gravity greater than the metal, reducible by
                         29                     ' ' 
338
O  X 1
the voltaic  pile,  particularly when  aided  by mercury;
fusible at red heat.   Exposed to a high temperature with
oxygen gas, it combines  with  it and becomes a deut-
oxide.  It  is not acted upon by boron, nitrogen, hydro-
gen, or carbon.   Phosphorus,  sulphur, selenium, chlo-
rine,  and  iodine  act upon  the protoxide  of potassium,
(see Oxides Metallic).  Exposed to contact with the air.
it attracts humidity and carbonic acid, and the result is
a liquid sub-proto-carbonate.  At a high temperature one
part attracts the oxygen of the air, and the other carbonic
acid, from  which there is a formation of the deutoxide
and proto-carbonate;  but in  continuing to heat it for
some time  the mass is converted into the  proto-carbonate
of potash.   It  is obtained  in laboratories by exposing
potassium  in thin plates to very dry oxygen gas.  Care
must be used not to  employ atmospheric air which con-
tains carbonic acid,  and which  is more  or  less charged
with water, for it has such an affinity for  water, that at
its highest  temperature it retains a quarter of its weight
of water.   In this state it is known by the name of the
hydrate of  the protoxide of potassium, or potash.
   Potash was formerly called  kali and vegetable alkali,
on account of its being obtained in a pure state by the
lixiviation  of vegetables.   Weeds are  found to afford
more"" ashes and  more salt  than wood.  The  weeds  or
wood should be burned within  doors  on  a  grate, and the
ashes laid  in a chest as fast as they are produced.   The
ashes should be lixiviated with  twelve times their weight
of boiling  water.  The ley thus formed should be evapo-
rated to dryness in iron pans or pots.   The salt thus pro
duced is of a dark  colour and contains  much extractive
matter, and being formed in iron pots, is called potass or
potassa:  The  extractive matter of this pure potash is
burnt off in a reverberatory furnace.  Much care should
be taken to prevent the potash from melting, as the ex-
 tractive matter would not then be  perfectly consumed. 
O  X I
339
and the alkali would form such a union with the earthy
parts as could not easily be dissolved.   When the salt is
thus refined it is called pearlash.
   Potash for use in the arts is often obtained by throwing
into an iron basin heated to redness, a mixture of the ni-
trate of potash, (saltpetre,) and pulverized cream of tar-
tar.   The  mixture takes fire, much azote is thrown off;
water and  carbonic acid are formed from the elements of
the two acids ; all the products volatalize except the carbo-
nic acid, which combines with the potash, forming a sub-
carbonate.   This  is dissolved in three times its weight of
water ; an equal part of  quick lime diluted in 12 times its
weight of water  is added; it is then boiled, water being
added in proportion to the evaporation which takes place.
The carbonic acid of the potash unites to the lime, form-
ing an insoluble sub-carbonate of lime, and the potash de-
prived of carbonic acid remains in  solution in the liquid.
It is boiled until the liquid no  longer precipitates  lime
water ; the solution is then filtered ; the residuum remain-
ing upon the filter is washed with boiling water until the
waters of the  washings are nearly tasteless;  all these
waters are united and evaporated to dryness;  the  mass
which results from the evaporation is then fused by heat,
poured upon marble, and when partly cooled it is put up
in flasks, which are hermetically sealed.
   The potash most commonly used in  commerce is com-
posed of the sub-carbonate, the muriate, and sulphate of
potash, silex,  hme, the  oxides of iron and manganese.
Potash in ancient medical  books was called potential cau.
tery.   The protoxide of  potassium consists of 100 of me-
tal and 20 of oxygen.  The hydrate of the protoxide, ac
cording to Thenard, consists of 25 parts of water to 100
of the protoxide.  Potash  is employed in the making of
glass ; it is the basis of all the common soft soaps ;  it en-
ters into the composition  of saltpetre, alum, dec.;  it is
*he basis of many salts used in medicine and in the arts; 
340
O  X 1
combined with water in the state of a hydrate, it is of fre-
quent use in medicine.   It exists in nature only in combi-
nation with acids.
  Oxide of Rhodium (Deuto.)  (Deutoxide de Rhodi-
um.)  Brown, combines with difficulty  even with  the
strongest acids.   It acts with the alkalies in a manner
analogous to the deutoxide of gold.   It can be obtained
by strongly  calciningj pulverized rhodium with caustic
potash, and  the nitrate of potash ;  the mass is lixiviated
and brought in contact with sulphuric acid  in order to
attract the alkali which it contained.   According to Ber-
zelius, it consists of 100 of rhodium and 13-32 of oxygen.
  Oxide of Rhodium  (Proto.)   Black, pulverulent;
mixed with a deoxygenating body it explodes, and is re-
duced.   It is obtained by heating rhodium in contact with
the air.   Berzelius states that it consists of 100 of metal
and 6-66 of oxygen.
  Oxide of Rhodium (Trito or Per.)  Solid, red, pul-
verulent ; at a feeble heat it loses part of  its oxygen and
becomes a black protoxide.   It is  procured by decom-
posing a solution of the chloride of rhodium by potash or
soda.  According to Berzelius, it contains three times as
much oxygen as  the  protoxide.  None of the oxides  of
rhodium are of use.
   Oxide of Selenium.   (Oxide de  Selenium.)  Disco-
vered by Berzelius ; it has never been obtained in a state
of purity, no method having yet been discovered for se-
parating it from the air with which it is  mixed.   It ap-
pears to  be  gaseous, colourless, without action upon ve-
getable colours.  Its odour resembles that of cabbage  in
a decaying  state; water dissolves but a  small quantity,
but sufficient to imbibe its odour.  It is obtained by burn-
ing selenium under a small bell-glass filled with air or hy-
drogen gas.
   Oxide of Silicium.  (Oxide de  Silicium, ou  Silice.)
 (From a Hebrew word Selag.)  Silex.  White, inodorous. 
0  X I
341
 insipid, rough to the touch, infusible with the  most in-
 tense heat, without action upon imponderable fluids, oxy-
 gen,  atmospheric air, and  all combustible non-metallic
 bodies.  Silex is extensively  diffused  in  nature, some-
 times in a state of purity, sometimes in combination with
 alumine, iron, manganese, soda,  potash, dec.   It is very
 pure in the  hyaline quartz, crystallized  in beautiful six.
 sided prisms terminated by pyramids with six faces ;  sand
 and the white free stone are almost wholly composed of
 it; it  constitutes  the  greater part  of  agate,  cornelian,
 opal,  mill stones, dec.   It is found in solution in water, in
 most vegetables,  dec.
    Pure silex is obtained in laboratories  as follows :  pow-
 dered flint or quartz is mixed with 2 parts  of potash and
 heated in a  crucible to a red  heat;  the  mass swells and
 at length fuses; the matter is then poured  into a capsule
 and boiled with 3 times  its weight of water;  the liquor
 is filtered and a little strong  acid poured upon it;  much
 carbonic acid is disengaged, a salt  based upon potash is
 formed, and  the silex is precipitated  in the  form of a ge-
 latinous hydrate;  the liquor is decanted, the precipitate
 washed with many waters, collected upon a filter, and
 dried;  it is  then calcined to redness and  preserved for
 use.   If the silicated potash  should  be  dissolved in too
 great a quantity of water, it would not  form a precipi-
 late by the addition of an acid; it would then be neces-
 sary to evaporate the liquor in order to increase the cohe.
 sion of the silex.
   This substance has been  known from the earliest anti-
 quity ;  ancient chemists called it vitrifiable earth, because
 it  entered into the  composition of glass.  It was after-
 wards  called silex;  after the  discovery  of potassium, it
 was by analogy ranked among the metallic oxides; but
 Berzelius has recently insulated silicium, and from  this
learned chemist it  appears that it should no longer retain
a place among the metallic oxides, (see Silicium.)  Silex 
342
O  X I
is very useful in the arts; it is the base -of all glass and
earthen ware, even of porcelain;  it is employed in re-
ducing some  ores to a metallic state, as those of copper,
iron, dec.
   Oxide of Silver.  (Oxide d'Argent.)  Pulverulent, of
an olive green colour ; insipid, without action upon air or
oxygen ; alterable  by  light,  reducible  by a feeble de-
gree of heat.   It is a product of art ; it is obtained by
precipitating  a solution of the nitrate of silver, by potash
or soda; the precipitate is filtered, and washed  man\
times in order to obtain the oxide of silver perfectly pure.
It  is  said that silver which  has been kept in the air for
some time  in a state  of fusion, absorbs  oxygen; this
oxide is however but transient, it reduces as soon as the
temperature is lowered.  The oxide of silver is in  labo-
ratories employed to obtain very pure oxygen : According
to Gay-Lussac and  Thenard, it consists of 100 of metal
and 7-8 of oxygen.
   Oxide of Sodium (Deuto.) (Deutoxide de Sodium.) It
contains more oxygen  than the deutoxide of potassium  :
it is at first deliquescent, becomes efflorescent, on expo-
sure to the  air ; it loses part of its oxygen at a high tem-
perature ; for this reason, in  order to obtain it, sodium is
first burnt in oxygen, and afterwards treated with this gas ;
as the combustion alone produces only the protoxide.
   Oxide of Sodium (Proto.) (Oxide de Soude)  Soda.
Solid, white, very caustic ; it strongly greens the infusion
of violets ; acts with combustibles in a manner analogous
to the protoxide of  potassium; like that, it is deliquescent
by attracting  the carbonic acid of the air, and becoming
efflorescent.   It exists in nature only in the state of com-
bination with acids, and some metallic  oxides.   It is ob-
i ained by burning the  metal  in oxygen gas.  The pro-
toxide of sodium like that of potassium, has such an affinity
for water, that it always retains a certain quantity even at
the highest temperature, and it is in  the state  of a hydrate 
0  X I
343
 of the protoxide of sodium that this substance is employed.
 It is obtained by treating the sub-carbonate of soda, suc-
 cessively by lime and alcohol. It is not easily decomposed
 by fire.  Soda has important uses in the arts ; combined
 with silex, it forms glass ; united to oil and grease, it forms
 hard  soap ; with chlorine it forms common salt; and with
 the acids a series of salts of great importance in medicine
 and in the arts.  According to Gay-Lussac and Thenard,
 the  protoxide of sodium consists  of 100 of metal and
 33-995 of oxygen.   Berzelius states  the  proportion of
 oxygen at 34-372.
   Oxide of Strontian (Deuto.) (Deutoxide  de Stron-
 tium.)  This oxide is known only in the state of a hydrate.
 In this state, it is in  thin  pearly  scales,  little soluble  in
 water.   It  partly decomposes by drying ; it is alkaline.
 greens the infusion of violets,  reddens curcuma paper.
 It is obtained by pouring a solution of strontian into oxy-
 genated water ; as it is soluble it is deposited with facility.
 It is washed by decantation and preserved for use.
   Oxide  of Strontian (Proto.) Strontian.  It  is of a
 whitish gray, of a bitter taste, caustic, strongly greens the
 infusion of violets, reddens curcuma paper.   Exposed to
 the air, it  attracts carbonic  acid,  and passes to the state of
 a sub-carbonate of strontian.  Boiling water dissolves it;
 on cooling, it deposites lamellar crystals.  Strontian  exists
 in nature only in the state  of combination with carbonic
and sulphuric acids, more commonly with the latter. This
substance is obtained by decomposing the nitrate of stron-
tian at a red heat.    The protoxide of strontian is com-
posed  of  100 of metal and  18-273 of oxygen.  It was
discovered by Klaproth,  but it is to Pelletier and Vauque-
lin that we are chiefly indebted for a knowledge  of its pro-
perties ; it was considered as an  elementary body until
the discovery of the alkaline metals.   It is only used in
chemistry.
                                             t 
344
0  X I
  Oxide of Tantalum.  (Oxide de Tantale.) See Oxide
of Columbium.
  Oxide of Tellurium.  (Oxide de  Tellure.)  White,
fuses below red heat; oxygen and atmospheric air do not
act upon it.  Strong acids  easily dissolve it; with  the
alkalies it in a degree performs the part of an acid, and
gives products which are little soluble.   It does not exist.
in nature ; it  is procured by decomposing the nitrate of
tellurium by heat.  According to Berzelius, it consists of
100 of tellurium and 24-797 of oxygen. It was discovered
by Klaproth.
  Oxide of Thorinum. ( Oxide de Thorinum, ou Thorine.)
 Thorina.  White, without odour or taste, infusible, not
reducible by the voltaic  pile, or  by any known means,
insoluble in water.   Exposed to the air  it attracts car-
bonic acid, and gives it off at red heat.    It dissolves in
nitric, sulphuric, and  hydro-chloric acids,  producing salts
which have an astringent taste.   The following process
for obtaining thorina is given from Berzelius : the pulver-
ized gadolinite of Korarfvet  is dissolved  in hydro-nitro-
chloric  acid (nitro-muriatic)  ; this  forms the hydro-chlo-
rates of yttria, of cerium and  thorina ;  from  these  the
iron  is separated by the acidulated succinate of ammonia.
After having saturated the excess of acid of the solution
by caustic  ammonia,  it is filtered in order to separate the
succinate of iron ; sulphate  of potash is poured into the
liquor, which precipitates the cerium ; the liquor is again
filtered,  and an  excess  of ammonia added ;  the  yttria
and thorina are precipitated ; the  precipitate  is washed
with many waters, and redissolved in hydro-chloric acid ;
the hydro-chlorates are evaporated to dryness, and boiled
with water, which dissolves that of yttria, and decomposes
and precipitates that of thorina.   By washing and drying
the precipitate, the thorina is obtained pure.   This sub-
stance is very rare.  Berzelius could only obtain it from 
0  X 1
345
 the deuto-fluates of cerium and yttria, and in  the  gadoli-
 nite of Korarfvet.
   Oxide of Tin (Deuto.) (Deutoxide d'Etain.)  White,
 '■ indecomposable  by fire, unalterable  by the air.   This
 oxide dissolves in potash, on account of which property
 Berzelius gave it the name  of stannic (stannique) acid. It
 exists abundantly in  nature in  Cornwall, England;  in
 Saxony, Bohemia, Spain, dec   It also forms rich mines
 in China, Malacca, and Mexico.  This  natural  oxide is
 sometimes  crystallized  in  quadrangular  prisms ;  it is
 always coloured by a little oxide of iron.   The deutoxide
 of tin is obtained  in laboratories by treating small bits of
 tin with nitric acid.  It may also be procured by calcining
 tin in contact with the air ; the deutoxide of tin is not em-
 ployed in the arts.
  Oxide of Tin (Proto) (Protoxide d'Etain.)  Blackish
 gray, reducible by the voltaic pile, insoluble in water and
undecomposable by fire.   This  oxide heated in contact
with the  air, easily inflames and passes to the state  of a
deutoxide.   It  is obtained by decomposing a solution of
the proto-chloride of tin by  ammonia.   It is at first  pre-
cipitated in the  state of a white hydrate ;  but it blackens
if dried with a gentle heat- According to Gay-Lussac and
Berzelius, it consists of 100 of tin and 13-6 of oxygen.
 The deutoxide, according to the same chemists, is formed
 of 100 of tin, and 27-2 of oxygen.
  Oxide  of Titanium.  (Oxide de  Titane.)  White,
almost infusible, dissolves in acids after  its cohesion is
destroyed.  It  is found in nature, but always in primitive
countries.   It  constitutes the anatase of Saint Gothard,
dec ; combined with lime and silex it forms the mineral
called sphene :  the oxide of titanium  is generally found
with the oxide  of iron, silex, dec M.  Laugier has given
a process for obtaining this oxide ; it consists in calcining
at a  high temperature  the  natural  oxide  with the  sub-
rarbonate of potash ; lixiviating the mass, dissolving the 
340
O  X 1
residue in hydro-chloric acid by the aid of a gentle heat ,
pouring into the liquor  oxalic acid ;  washing the precipi-
tate, drying, and calcining it in order  to expel the little
hydro-chloric acid which it might have retained, and to
decompose  the oxalic acid ; the  oxide of titanium will
remain pure.
  Oxide of Tungsten.  (Oxide de  Tungstene.)  Dark
brown. This oxide is very little known ; it is unalterable
by the air, and insoluble in water, it does not  exist  in
nature.  It is procured by passing at red heat a current of
hydrogen  gas through a  porcelain tube.  It has been
observed that  if the temperature is greatly  elevated, a
blue oxide has been obtained which seems to be distinct
from the brown oxide.  The oxide of tungsten is formed
of 100 of metal and 16-564 of oxygen.
  Oxide of Uranium (Proto.)  Oxide d'Urane.  Blackish
gray, almost infusible, without  action  upon atmospheric
air and oxygen gas, at any temperature.  It is obtained
by strongly heiting the metal in contact with the air.  It
is found in nature in Saxony, Bohemia, dec*  According
to  Berzelius,  it is composed  of 100 of uranium, and
0-360  of  oxygen.  It was discovered by Klaproth, and
studied by Bucholz, who admitted  six  oxides of the
metal.
  Oxide of Zinc  (Deuto.)  Deutoxide de Zinc.)  Dis-
covered by Thenard ; it was obtained  by means of oxy-
genated water, by a  process  similar to that used in the
preparation of the tritoxide of  copper.   It is white, in-
sipid, and inodorous ; it decomposes spontaneously ; thus
it has but an ephemeral existence.   It dissolves in acids,
losing part of its oxygen.
  Oxide of Zinc (Proto.) (Protoxide de Zinc.)  White,
insipid, inodorous, fixed, difficult to fuse, reducible by the
voltaic pile, without action upon the air ;  at the ordinary
* It is said to be found near Baltimore, in Maryland. 
0  X I
34'
 temperature, it absorbs a little carbonic acid.   This oxide
 is very rare in nature ;  it is  found only in America.
 This should not be confounded with calamine, which is a
 silicate and carbonate of zinc.  The protoxide of zinc is
 obtained by heating to redness the fused metal, in a cru-
 cible in the open air; the zinc  burns with a  beautiful
 green flame, and forms at its surface a wool-like covering ;
 this is  gradually taken off with  a spatula; a portion of
 this oxide rises into the   atmosphere, and  resembles
 (lakes of snow.   It was formerly called flowers of zinc,
 (oxide de zinc sublime,) nihil album, philosophorum lana,
 dec  It is formed of 100 of metal, and 24-797 of oxygen :
 it is used in medicine.
  Oxide of Zirconium.  (Oxide de Zirconium, ou Zir-
cone.)   Zirconia. Zircon.  White, insipid, inodorous, un-
alterable by imponderable fluids, reducible by potassium.
It is said to contain of the  metal 100 parts to 65  of
oxygen.   One  method for  obtaining it, is to  heat in a
silver crucible, 1 part of finely powdered  zircon  with 2
parts of potash;  dilute the mass in distilled water, wash
and  filter it; the  residue  remaining upon the filter, is
composed of silex, zirconia, and the oxide of iron ; this is
treated by hydro-chloric acid, which dissolves all  except
the silex; the liquor is filtered again ; ammonia is  poured
into it, which precipitates the zirconia  and the oxide of
iron, in the state  of a hydrate ; after being well washed,
the latter is separated by oxalic acid ; it forms a soluble
oxalate of iron, and an insoluble oxalate of zirconia ; the
washings are repeated, and then by calcination, perfectly
pure zirconia is obtained.   This substance was disco-
 vered by Klaproth.
  Oxide  of  Yttrium.    (Oxide d'Yttrium.)   Yttria.
 White, insoluble, inodorous, insipid, infusible by the heat
of the  furnace, unalterable by the imponderable fluids ;
without action upon  oxygen gas and combustible bodies;
it attracts carbonic acid from the air.  It  has yet been 
318
O  X Y
 found only in the gadolinite, the yttro-tantalite, the yttro-
 cerite.  Its preparation is long and difficult.   Yttria was
 discovered by Gadolin, in 1794,  and  has since been
 studied by Vauquelin and Klaproth.  It was regarded as
 a simple substance until the discovery of potassium  and
 sodium.
   Oxiodine.   A name  applied by Sir H. Davy, to  an-
 hydrous iodic  acid.  It is a semitransparent, inodorous,
 white substance,  with a sour astringent taste.   When
 exposed to a heat of 500°, it  fuses  and changes  into
 oxygen and iodine.
   Oxygen.  (Oxigene.)  (From the Greek oxus, acid,  and
 gennao, to produce, because it generates acid.) A colour-
 less gas, inodorous, insipid, invisible ; its specific gravity
 is 1-1026; that of the  air being  taken  for unity.   All
 efforts made to liquefy it have hitherto been vain ;  when
 strongly compressed in a glass cylinder, it heats to the
 luminous point.   According to Berzelius, oxygen of all
 known bodies is the most electro-resinous.  This body is
 unalterable at the highest temperature, by  all known
 agents.  It is indispensable to combustion,  and to the
 respiration of animals;  of all  substances,  it  acts  the
 most important part in chemistry, being an  element of
 all acids and oxides.   Mixed with nitrogen, it constitutes
 atmospheric   air; combined  with  hydrogen, it  forms
 water; in short, it is one of  the constituent elements of
 all minerals and  vegetables.   It exists  every where ; is
 capable of conbining with all  bodies,  often  in  differen
 proportions.
   Oxygen gas was discovered nearly at the same time,
 by three distinguished chemists.   Prieslty,  who first  dis-
 covered it, called it dephlogisticated air.   Scheele, without
 any knowledge of the labours of Priestly,  discovered it
 sometime afterward, and called it the air of fire (air de
feu.)  The illustrious Lavoisier, after having studied its
 properties, called it  eminently respirable air, (air  emi- 
0  X Y
349
  icmmentrespirable;) afterward, on account of the acidifying
 property supposed to belong to  this gas exclusively,  he
 designated it by the word oxygen, composed of two Greek
 words, which  signify to engender acids.  This name
 being very convenient, has been  universally adopted;
 but since the discovery of the  hydracids, and the estab-
 lishment of the fact that hydrogen  and many other sub-
 stances can produce acids without the aid of oxygen, that
 general hypothesis has been abandoned, and k has been
 perceived that  the term  oxygen, in its  strictest sense
 as signifying the producer of acid, is incorrect;  this term
 however  having been  establised by usage,  no attempt
 has been made to substitute any other name for the im-
 portant substance which it represents.
   Although oxygen is diffused throughout all nature , it is
 never found in  a state  of purity; it may be obtained  by
 one of the  following  processes :  1st. A stone retort is
 almost filled with the peroxide of manganese ;  to the
 neck of the  retort is fitted a bent tube, which communi-
 cates with the pneumatic cistern ; the retort is gradually
 heated to redness ;  the gas disengages, passes out at the
 extremity of the tube, and is collected under a bell-glass
 or  phial  filled with water; the first portions  of the gas
 which  come over,  are  rejected  on account  of being
 mixed  with  the atmospheric air  which was in the retort
 and tube, and in some cases also with a little carbonic
 acid, derived from some  carbonates which exist in the
oxide of manganese.   It is  a very good precaution  to
 wash the oxide  of manganese with a little diluted muriatic
 acid, and  to dry it before  using.  The operation  of col-
 lecting the gas  is known to be terminated, when at a red
 heat oxygen no longer passes over.  One pound of the
oxide of manganese of commerce  ordinarily furnishes from
 4 to 5 gallons of this gas.
  2d. Another method of obtaining oxygen gas, is to treat
the peroxide of manganese with diluted sulphuric acid*
                         30 
350
O  X Y
For this purpose a tubulated retort may be one third filled
with manganese; the sulphuric acid  is poured through
the tubulure; the apparatus is fitted as in the preceding
case, except that the heat of the sand bath is sufficient to
reduce the manganese.
  3d. Oxygen gas may be obtained by decomposing at a
gentle heat, the chloride of potash in a small retort.
  4th.  The oxide of silver may  be decomposed in the
same way.   The last two methods furnish oxygen per-
fectly pure; in the first  case  the chloride of  potasium
remains, and in the second the silver is reduced.
  5th.  Oxygen may be obtained from the red oxide of
lead.   Pure oxygen  is employe^ only in  chemistry;
though at the  period of its  discovery, physicians enter.
tained great hopes respecting  its utility in the cure  of
diseases, particularly that of the  lungs ; but experience
proved that it  produced upon these  organs too great  a
degree of excitement, and at length caused the destruc-
tion of animals who for any length of time respired it.
  Oxygen  was discovered  in  1774.  For an accurate
knowledge  of this important  element of nature, the
reader is referred to the chemical  treatise of Fourcroy.
  Oxygenation.  Differs  from  oxidation,  in being  a
more .general term ; every union  with oxygen, whatever
the product may  be,  is oxygenation; but oxidation take
place only when an oxide is formed.
  Oximuriates.   See Chlorates  and Chlorides.
  Oxymuriatic  Acid Chlorine.
   Oxysulphurets.  (Oxisulfures.)  See Sulphurets. 
P A I
351
                         P.

   Paints.   "In  the  Philosophical  Transactions  for
1815, Sir H. Davy has communicated the resultsof some
interesting researches,  which he made at Rome, on  the
colours used by the ancient artists.
   He  found  the  reds  to be minium, ochre,  and  cin-
nabar.
   The yellows were ochre, orpiment, and massicot.
   The blues were formed from carbonate of copper,  or
cobalt, vitrified with glass.
   The purple were  made of shell-fish, and probably also
from madder and cochineal lakes.
   The blacks and browns were lamp-black, ivory-black,
and ores of iron and manganese.
   The whites were chalk, white clay, and ceruse.
   The Egyptian azure, the excellence of which is proved
by its duration for seventeen hundred years, may be easily
and cheaply made.  Sir H. Davy found that 15 parts by
weight of carbonate of  soda, 20 of powdered opaque
flints, and 3 of copper  filings, strongly heated together
for two hours, gave  a substance of exactly the same tint,
and nearly the same degree of fusibility, and when pow-
dered, produced a fine  deep sky blue.
   He conceived that next to coloured frits, the most per-
manent pigments are those furnished by the peroxides or
persalts, such as ochres, carbonates of  copper, patent
yellow, (sub-muriate of lead,) chromate of lead, arsenite
of copper, insoluble chloride of copper, and sulphate of
barytes.
   M. Merime inserted a note very interesting to painters
in the " Annates de Chimie  et Phys." for  June, 1820.
When carbonate of lead is exposed for some time to va-
pours of sulphuretted hydrogen, it becomes black, being
r on verted to a sulphuret.   This white pigment, employed 
352
PAL
  with  oil, and  covered with a varnish which  screens it
  from  the air, may be preserved for many hundred years
  as the paintings of the 15th century prove.   But when
  the varnish is abraded or decays, the whites of ceruse
  are apt to contract black specks  and form spots which
  ruin fine paintings.  Miniatures in water colours are fre-
  quently injured in this way.  M. Thenard was requested to
  occupy himself with the means of removing these stains
  without injuring the rest of the picture.   After some tri-
  als  which proved that the reagents which would  operate
 on sulphuret of lead would equally attack the  texture  of
 the  paper,  as  well  as  the  colours, he recollected that
 among the numerous phenomena  which his discovery  of
 oxygenated water had presented to him, he observed the
 property it possessed, of converting instantly the black
 sulphuret of lead into  the  white sulphate of the same
 metal.  He gave a portion of water, containing about
 five  or six  times its volume of oxygen to an artist who
 had a  fine picture of Raphael spotted black.  On apply-
 ing a  few  touches of his pencil, he perceived  the stains
 vanish  as if by enchantment, without affecting  the other
 colours in the slightest degree."*
   Palladium.   A solid metal, of the colour of silver,
 hard, very malleable, specific gravity 11-3.  It has no
 action  upon atmospheric air and oxygen gas ;  it can only
 be fused with the gas blow pipe;  in this state Vauquelin
 observed that it burnt  with  an appearance of brilliant
 flames  (aigrettes.)  When a jet of hydrogen is passed
 upon spongy palladium, the metal reddens and water is
 formed.  It has been  united to sulphur, chlorine, selc
nium, and several metals.   This metal is very rare, and
it has yet only been procured from the ore of platina'.  It
was discovered in 1803 by Wollaston and studied by
Vauquelin and Berzelius.
* Dr. Ure 
PET
353
   Panacea.   (Panacee.)  From  the Greek pan, all or
 universal, and akos, medicine, signifying universal medi-
 cine, or one which should cure all diseases.  The search
 for this medicine occupied the  attention of many of the
 alchemists.
   Panacea Mercurial.  An ancient name for the proto-
 chloride of mercury.
   Pancreatic Juice.   This fluid  differs from saliva.
 According to  Tiedemann and Gmelin, its principal con-
 stituents are  albumen and a curdy substance;  it con-
 tains also some osmazome.   It possesses some acid pro-
 perties.
   Pearlash.   An impure potash obtained  by lixiviation
 from the ashes of plants.
   Per-Carburets.  See Carburets.
   Per-Nitrites.   See Nitrites (Hypo.)
   Per-Oxides.   See Oxides.
   Per-Sulphurets.  See Sulphurets.
   Petrifactions.  " Stony matters deposited in the way
 A incrustation, or in the cavities of organized substances,
 are called petrifactions.  Calcareous earth,  being uni-
 versally diffused and capable of solution in  water, either
alone or by the medium of   carbonic or  sulphuric acids
which are likewise very abundant, is deposited whenever
the water or the  acid becomes dissipated.   In this way
we have incrustations of  limestone or of selenite, in the
form  of stalactites or dropstones, from the roofs of ca-
 verns and in various other situations.
   The most remarkable observations relative to petrifac-
tions are those given by Kirwan :
   1st. That those of shells are found on or  near the sur-
 face of the earth, those of fish deeper, and those of wood
deepest.   Shells are found in  immense quantities  at con-
siderable depths.
   2d. That those organic substances that resist putrefac-
:ion most, are freauentlv found Detrified ; such as shells 
354
P H L
and the harder species of woods :  on the contrary, those
that are most apt to  putrify are  rarely found petrified;
as fish, and the softer parts of animals.
  3d. That they are most  commonly  found in strata of
marl, chalk, limestone, or clay;  seldom in sandstone, still
more rarely in gypsum, but never in gneiss, granite, ba-
salt, or schorl ; but they sometimes occur among pyrites,
and ores of iron,  copper, and silver, and almost  always
consist of that species of earth,  stone, or other mineral
that surrounds them,  sometimes of silex, agate,  or cor-
nelian.
  4th. That they are found in climates where their ori-
ginals  could not have existed.
  5th. That those found in slate or clay are compressed
and flattened."*
  Petroleum.  See Naphtha.
  Pewter. (Etain.)  Tin alloyed with copper or other
metallic  bodies;  as  lead, zinc, bismuth, and antimony.
The French word etain being  applied  both to  tin and
pewter, the two substances are often confounded.
  Pharmacy.   (Pharmace.)  (From  a Greek word sig-
nifying medicine.)   The art  of preparing medicine.
   Phlogiston.   (Phlogistique.)   (From the Greek phlo-
gizo, to burn.)   The supposed general inflammable prin-
 ciple of the chemists of the last age ;  they  imagined that
 it was pure fire, or the matter of fire, fixed in combusti-
 ble bodies, and distinguished from fire in action, or in a
 state of liberty.   Chemists imagined that  in every case
 of combustion phlogiston was  disengaged; on the con-
 trary, whenever a metal was reduced or a body became
 combustible, they imagined  it  absorbed phlogiston.  It
 may easily be seen  that this theory, although plausible, is
 erroneous; for were it true, it would follow that  bodies
 after combustion would be diminished in weight, whereas
* Dr. Ure- 
PHO
355
facts prove  the  reverse of this, as may easily be ascer-
tained by the experiment of burning a metallic wire in
oxygen gas; the metal is found to be heavier after com-
bustion.
   Phocenine. A fetid substance, of an odour resembling
that of ether,  very soluble in  boiling  alcohol, without
action upon litmus.  Phocenine treated by potash is trans-
formed  into dry phocenic acid, hydrated oleic acid, and
glycerine.   It exists in the fat of the porpoise combined
with phocenic acid  and elaine,  and in the  oil of the  dol-
phin united  to the same substances and  to cetine.  Pho-
cenine is obtained by dissolving the fat of the porpoise in
boiling  alcohol, leaving the solution  to cool, decanting
the alcoholic part, and submitting  the residue to distilla-
tion.  An acid is obtained which is neutralized by magne-
sia ; it is treated with cold  alcohol, which  dissolves all
the phocenine.   It  was discovered  by Chevreul.
   Phosgene.   A name  given  by Mr. John  Davy to
chloro-carbonous gas  (chloroxi-carbonique.)  See  Car-
bonous Gas.
   Phosphates.   Salts resulting from the combination of
phosphoric acid with bases.   All the  phosphates, except
those of soda and ammonia,  are insoluble ; they are
affected by fire like the borates.  Carbon at a high tem-
perature decomposes  them ; with the metals of the  last
four sections, whose oxides are reducible  by charcoal,
it  produces  carbonic  acid, and forms metallic  phosphu-
rets ; but with the oxides  of the first two sections, which
are not reducible by charcoal, it disengages phosphorus
and the oxide gas of carbon, while a sub-phosphate re-
mains.   Liquid phosphoric  acid dissolves all the phos-
phates.  All the strong acids unite with one part of the
base of the neutral phosphates,  forming  soluble  acid
phosphates.   These  salts  are  extensively diffused in
nature;  the phosphate of lime is most abundant, some-
times  consfitutinsr  whole  mountains,  and forming an 
356
P H O
 important part of all animal  bones.   There  are  phos
 phates with an  excess of the base, neutral phosphates
 acidulated phosphates, and acid phosphates.  The solu-
 ble phosphates  are  prepared by  adding the base to a
 solution of the acid phosphate of lime.  Those which arc
 insoluble are obtained by  double decomposition.
   According to Berzelius, in the neutral phosphates the
 oxygen of the oxide is to the oxygen of the acid as 2 to 5.
 The sub-phosphates contain  once  and a half as  much
 of the base as the preceding; the  acid phosphates con-
 tain only half as much of the base  as  the neutral  phos
 phates ; and the acidulated phosphates, three quarters.
   Phosphate of Alumine.   This  salt exists in nature ,
 it  constitutes  almost wholly  a mineral called wavelile.
 Vauquelin discovered it in a mineral  brought from the
 island of Bourbon.   It can be obtained only by decom-
 position.
   Phosphate of Ammonia.   (Phosphate d'Ammoniaque.)
 Solid, white,  without action upon atmospheric air; it
 greens the infusion of violets.  Exposed  to the action o'
 fire, it disengages all the  base,  the phosphoric acid re-
 maining fused and transparent.  It is obtained by  pour-
 ing liquid  ammonia into  the acid phosphate of  lime ; the
 sub-phosphate of lime is  precipitated, separated  by fil-
 tering the liquor, and afterwards suitably  evaporated and
 crystallized.   A slight  excess of  ammonia  should be
 added;  because by evaporation  the salt soon becomes
 acid.  The phosphate of ammonia is employed to obtain
 phosphoric acid.  Gay-Lussac  has demonstrated  that
 any kind of cloth impregnated with phosphate of ammonbi
 is incombustible.  At the approach  of a burning body the
 salt decomposes; all the  ammonia is  disengaged; and
the phosphoric acid  covers the tissue with a kind of var-
 nish which opposes the action of fire.
  Phosphate  Ammoniaco-Mag>esian.   White,  solid,
semi-transparent, vitrifiable at a red heat.  By trituration 
P H O
357
 with an alkali it  disengages  ammonia; it is soluble in
 sulphuric acid, and insoluble in a solution of the alkalies,
 and  is prepared  by saturating the  acid  phosphate of
 magnesia with ammonia.
   Phosphate of Barytes.   (Phosphate de Baryte.)
 Solid, white, pulverulent, insipid,  without  action  upon
 atmospheric air and upon vegetable colours, insoluble in
 cold and  boiling water.   Treated with  ammonia, if
 passes to the state of a s 'b-phosphate.   Phosphoric acid
 and  the strong acids transform  it  successively into an
 acidulated phosphate and an acid phosphate of barytes.
 This salt is obtained  by decomposing a solution of neu-
 tral  phosphate of ammonia, by another solution of the
 chloride of barium, equally neutral;  the  phosphate of
 barytes precipitates, and is  separated by filtering.   Be-
 sides the neutral  phosphate above  described, there are
 two acid phosphates of the same  base.   They are ob-
 tained by processes analogous to the preceding.
  Phosphate of Copper. (Phosphate de Cuivre.) Green,'
 insoluble, unalterable  by the air;  crystallizing in rhom-
 boidal prisms, or in rectangular octoedrons.   It is found
 native in Hungary and many other countries, but usually
 in small quantities.  This phosphate may be obtained by
 double  decomposition.  According to Berthier, it  con-
 sists of 64 parts of phosphoric acid and 29 of the deut-
 oxide of copper.
  Phosphate of Cobalt.  Blue of Thenard, or  Cobalt
blue.  See Blue.
  Phosphate of Iron.  (Phosphate de Fer.)  Blue, some-
times in crystals, sometimes  in amorphous  (shapeless)
masses.   The crystals are usually in the form of  rect-
 angular prisms.   This  phosphate  is insoluble in  water,
unalterable by air ; it is a rare substance, is found in the
mines of Cornwall, England, in micaceous rocks  asso.
ciated with magnetic sulphuretted  iron ;  in Bavaria, and
in the volcanic products of the island of Bourbon,   In a 
358
P H O
pulverulent state it is found only in the argellites of the
newest formation.  According to Fourcroy it consists of
22 parts acid, 44 of the protoxide of iron, and 34 of water.
This salt may be artificially obtained by decomposing a
solution of the sulphate of iron by the phosphate of soda
or potash.  It has no use  in the arts or in medicine.
  Phosphate of Lead.  (Phosphate de Plomb.)   This
varies in colour, sometimes it is green, sometimes brown,
yellow, dec   It  usually contains the arseniate of  lead.
It is found in France, in the Hartz mountains, and in the
Lead Hills of Scotland.*  It crystallizes in hexahedral
prisms more   or less regular.   Klaproth, who analyzed
this natural phosphate, found it formed of 76 of the  oxide
of lead  and 24  of phosphoric  acid.  It is prepared b)r
double decomposition.  A sub-phosphate  of  lead is ob-
tained by boiling the native phosphate with ammonia.
  Phosphate of Lime.  {Phosphate de Chaux.)   White,
pulverulent, insipid, without action upon vegetable co-
lours.   It acts with the acids like the phosphate of ba-
rytes.   This salt does not  exist  in nature.   It is prepared
by pouring a solution of the chloride of lime into a solu-
tion of the neutral phosphate of  soda ;  the phosphate of
lime  is immediately  precipitated.   Berzelius  observes,.
that if we should invert this process,  that is, should pour
the phosphate of soda into the chloride of lime, only the
phosphate with an excess of the  base would be  precipi-
tated, and the liquor would become acid.  It consists of
100 of acid and of 79-838 of lime.   Berzelius, besides
these neutral phosphates, admits four others;  two sub-
salts and two super-salts.  One of these sub-salts is some-
times found  crystallized; in this state  it is known bj
mineralogists by the  name  of apatite.   The same sub-
phosphate of lime constitutes almost all the hard parts ol
bones.   It is of much use in the arts.   Chemists usually

  * It is found in some parts of the United States, as in the load mines of Penti
sylvania and of Southampton in Massachusetts. 
P H O
359
extract phosphorus from the sub-phosphate of lime.  See
Phosphorus.
  Phosphate of Potash.  This  salt is  known only in
solution ;  when an attempt is made to crystallize it during
evaporation,  it separates into  an acid phosphate which
crystallizes, and an alkaline phosphate which is deposited
in the form of a jelly.   It has a strong taste and is unde-
composable by fire.   According to Saussure, it can dis-
solve a quantity of lime and form a phosphate of calca-
reous potash.   The same chemist dissolved a large quan-
tity of the phosphate  of lime by boiling  it with potash :
but the calcareous  phosphate must be hydrated, other-
wise the cohesion would be too strong, and there would
be little or no action.    It exists in the seeds of the cere-
alia, or the gramineous vegetables, and is prepared  b\
pouring a solution of the  sub-carbonate  of potash into
the acid phosphate of lime.  It can also be obtained  by
a direct process.
  Phosphate of Soda.  (Phosphate de Soude.)  Crytal-
lizes in rhomboidal prisms, transparent, rendered soluble
by heat.  Exposed to the air, this salt  parts with a portion
of its water of crystallization and effloresces.   Submitted
to the action of fire it first undergoes the aqueous, then
the  igneous  fusion ;  at a cherry red it produces  an
opaque glass.  The phosphate  of soda greens the infu-
sion  of violets, for this reason Thenard considers it as a
sub-phosphate.  It is prepared  by calcining bones in a
furnace ;  when very friable,  they are reduced to a fine
powder, sifted, mixed with water and  two thirds of their
weight  of sulphuric  acid; the mass becomes heated,
swells, and disengages carbonic acid  from the carbonate
of lime contained in the bones ;  the mass  is again diluted
with water and filtered; all the lime remains upon the
filter while the acid phosphate of lime, which is very so-
luble, passes through.   Into this solution  is poured car-
bonate of soda, until the liquor becomes so alkaline as to
green strongly the infusion of violets ; a violent efferves- 
360
P H O
 cence takes place, followed by  a gelatinous precipitate
 of the phosphate oflime ;  it is again filtered,  the preci-
 pitate washed and suitably evaporated ;  the phosphate of
 soda in a day or two crystallizes.  If the mother-waters
 were  acid or even neutral, it would be  necessary to add
a new quantity of the carbonate  of soda.   This salt is
used in  the arts for the preparation of cobalt blue  (The-
nard's blue).  It is employed in medicine.
  Phosphate of Uranium.  (Phosphate d'Urane.)  It
exists in nature in small quantities.  It is crystallized in
lamellar clusters.  It is of a yellow or green colour ; in
the latter case, it contains copper, such as that of Eng-
land  and Siberia.  Phillips, who analyzed this natural
phosphate, found it composed of  10 parts of phosphoric
 acid,  75 of the deutoxide of uranium, and 15 of water.
   Phosphate of Yttria.   The  substance formerly de-
scribed  by Berzelius  under the  name  of Thorina, has
since been ascertained to be a phosphate of yttria.
  Phosphites.  Salts resulting from the action of phos-
phorous acid, with salifiable bases.  All  the phosphites.
exposed to heat, disengage phosphuretted hydrogen and
a little of phosphorus, and a phosphate  coloured by the
oxide  of phosphorus remains.   The phosphites thrown
upon burning coals, produce a yellow flame, which is in-
tense  in proportion to the quantity of acid. The phosphites
of potash, soda, and  ammonia, are excessively soluble ;
it  is  even impossible to crystallize the first.  Those of
strontian, lime, and barytes, can crystallize only by spon-
taneous evaporation ;  at 212° they  separate into acids,
phosphites, and sub-phosphites.   Gay-Lussac observed
that the phosphites could absorb oxygen gas, and become
phosphates,  without any particular change at the points
of saturation.  All these  salts are the products of art ;
they are either obtained directly, or by double decompo-
sition.  It has been observed by some chemists, that the
oxides easily  reducible,  cannot combine with phospho-
rous acid.  According to Berzelius, in the  phosphites. 
P H 0
361
of the oxygen of the acid as 2 to 3.  See Memoirs by
Dulong and Gay-Lussac.
   Phosphites  (Hypo.)   Combinations of hypo-phos-
phorous acid with bases.  These salts have been studied
only by Dulong ;  they are aoted upon  by fire like the
phosphites,  and like them they disengage phosphuretted
hydrogen and  phosphorus,  being  changed into phos-
phates coloured by the oxide of phosphorus, but their vo-
latile products are more abundant than in the phosphites.
Upon burning coals they produce like the phosphites, a
yellow flame.  They are so  soluble that they cannot be
crystallized; they  transform chlorine  to hydro-chloric
acid and possess  the  property  of  reducing the salts of
gold and silver.   The hypo-phosphites are all the pro-
ducts of art; they are prepared by a direct process.
  Phosphorus.  (Phosphore.)  (From the Greek phos,
light, and phero, I  carry.)  A  solid body, white, some-
times yellowish or  reddish.  It is flexible, of the consist-
ence of wax, may be cut  with a knife, or  broken by the
fingers.  Its specific gravity is 1*770 ; it liquifies at 110°,
and according as it cools slowly  or  quickly, it takes dif-
ferent shades from white to black.  Phosphorus  may be
crystallized in little octoedral needles.  If fused in a phial
with water,  it appears  like a white oil;  and occupies, on
account of its specific gravity, the lower part of the ves-
sel ; by shaking it in this  state until the water is  cold,  it
is converted into a powder more  or less  fine.  At a tem-
perature a little more elevated, the phosphorus volatilizes ;
by this property chemists  are able to purify it; but it  is
necessary to use a retort  deprived of air, as in contact
with the air it inflames.  To the retort is  added a receiver
full of water in order to condense the phosphorus.
  Light has an  important effect upon phosphorus, turn-
ing it red when excluded from  all contact with the air.
When exposed to the air phosphorus becomes luminous,
and burns without being inflamed.   It does not, at the or
                          31 
362
P II O
 dinary pressure, burn in oxygen gas at a temperature be
 low 80° ;  but  if the pressure is diminished, phosphorus
 becomes luminous in the dark, and burns.   Nitrogen,
 by rarefying the oxygen of the atmosphere, acts like the
 diminution of pressure, and  singularly favours combus-
 tion.   When a small piece of phosphorus is burned on a
 plate under a bell-glass filled with  oxygen,  all the oxy-
 gen is  absorbed and solidified ; the sides of the bell-glass
 are covered  with phosphoric acid ; and on the plate re-
 mains a reddish substance, which is the oxide of phospho-
 rus.   Hydrogen brought in contact with phosphorus, dis-
 solves  a portion and changes it to phosphuretted hydro-
 gen (hydrogene phosphore) ; some red  star-like crystals
 are deposited, which M. Vogel  regarded as the oxide of
 phosphorus.
   Phosphorus forms combinations with most other combus-
 tible bodies.  It has not been discovered pure in nature-
 Combined with oxygen, it  enters into the combination of
 many  minerals,  and forms  a great part of the  animal
 frame ; united to oxygen, hydrogen, carbon, nitrogen,  it
 constitutes a part of  the nerves and brains of fish.   Phos-
 phorus is employed  in the arts for the construction of
 phosphoric matches ; in chemistry for the analysis of air
 and the preparation of phosphoric acid.   Its use in medi-
 cine  has been  attempted, but according to  the  experi-
 ments  of Pelletier and others, it too highly irritates the
 animal organs.   Phosphorus was  discovered by Brandt,
 an alchymist,  at Hamburg.   Scheele  and Gahn first
 obtained from it  bones.
   Phosphorus of Baudouin.   See Nitrate of Lime.
   Phosphorus of Bologna.  See Sulphate of Barytes.
   Phosphorus of Homberg.   See Chloride of Calcium.
   Phosphurets.  (Phosphures.)  Combinations of phos-
 phorus with combustible bodies.  Phosphorus unites with
 metallic combustibles, and to combustible bodies non-me-
^ralhc  All the metallic phosphurets are brittle, solid, and 
P H o
363
more fusible than the  metals  they contain, when  those
are fused with difficulty ; in the other case they are less
fusible ;  thus, the phosphuret of iron is more fusible than
iron ; while that of tin or  lead  is sensibly  less fusible
than lead or tin, taken in  their  separate state.  These
compounds have been  but imperfectly studied ;  yet there
is reason to  believe that they are subject to the same
laws of composition as the sulphurets ; of course there
may be as many phosphurets of a metal as there are sul-
phurets and oxides  of the same metal ; or, which is  the
same thing, a proto-phosphuret, in absorbing the quantity
of oxygen proper to burn the metal and phosphorus, may
be changed into a neutral proto-phosphate. (Dulong.) All
the phosphurets are insipid, except those  of the alkaline
metals, which  decompose water of the ordinary tempera-
ture ; some are susceptible of decomposition by fire.   It
is probable that all the  phosphurets, at an elevated tem-
perature, can obsorb oxygen gas and become phosphates.
The phosphurets were  discovered by Pelletier ;  they are
all the  products of art.   Various processes are used for
obtaining them :
  1st.  Dulong advises to make phosphorus in a state of
vapour pass upon the metal heated to redness.
  2d.  The metal to be phosphuretted is  to be  minutely
subdivided and melted  if it is fusible ; if not  fusible, the
metal should be heated to redness and phosphorus added
in small proportions ; one part of the phosphorus inflames
and the other combines with the metal.   Phosphorus  is
added  until the metal will absorb no more.  When the
metal oxidates easily by heat, a  little resin is  added in
order to  preserve it from contact with the air.
  3d.  A neutral  phosphate is treated with lamp-black in
a crucible lined with carbon ; at a high  temperature the
carbon unites with  the oxygen of the metal and phos-
phoric acid. 
364
PHO
   4th. Phosphurets whose metals have little affinity tot
 oxygen, are prepared by passing a  current of phosphu
 retted hydrogen into a solution of the salt.
   Phosphuret of Antimony.   (Phosphure oVAntimoine.)
 White,  of a metallic appearance,  crystallizes  in  little
 cubes.  It is very fusible, and decomposes by fire.  It is
 obtained by  fusing antimony in a Hessian crucible, and
 throwing upon it by degrees dry phosphorus.   It  must be
 taken from the fire  as soon as the last  portions of phos-
 phorus are added.
   Phosphuret  of  Arsenic.   (Phosphure   d'Arsenic.)
 Grayish black ;  it decomposes so easily that it cannot be
 preserved except under water.  It is obtained by heating
under water equal  parts  of phosphorus and the deut-
 oxide of arsenic ; one part of the phosphorus  absorbs the
 oxygen of the arsenic and passes  to the  state of phos-
 phoric acid, which dissolves in the water ;  the other part
 of the phosphorus unites to the reduced  metals.   Thb
 phosphuret may be prepared  by heating  equal  parts of
 phosphorus and arsenic in a small glass retort.
  Phosphuret of Bismuth.   (Phosphure  de Bismuth.)
 Black, pulverulent, decomposes at a moderate heat.  It
is obtained by decomposing a salt of bismuth with phos-
 phuretted  hydrogen;  it  is filtered  to separate the  pre-
 cipitate, washed  and dried with a gentle heat.
  Phosphuret  of  Cobalt.   (Phosphure  de  Cobalt.)
 Bluish white, brittle, more friable than  cobalt; at a high
temperature it absorbs oxygen and becomes a phosphate
 of cobalt.   It is  obtained by strongly calcining, in a cru-
cible lined with charcoal,  (creuset brasque.) a mixture of
4 parts of dry phosphoric acid, 4 parts of cobalt, and half
a part of charcoal.   It can also be obtained  by  passing
the vapour  of phosphorus upon cobalt heated  to  red-
ness.
  Phosphuret of  Copper.    (Phosphure de  Cuivre.)
White, brittle, very  hard  and brilliant.   When exposed 
P H 0
365
 to a great heat in the air, it produces a phosphate of cop-
 per.   Dulong obtained it by passing vapour of phospho-
 rus upon copper filings heated to redness in a porcelain
 tube.   That  which is prepared by throwing  phosphorus
 upon the heated metal is not saturated with phosphorus.
   Phosphuret of Gold.  (Phosphure d'Or.)  Black, pul-
 verulent, decomposes at a gentle heat;  it is obtained by
 heating gold to redness  in a porcelain tube, and intro-
 ducing the vapour of phosphorus.  Thenard  considers
 this phosphuret  as  not saturated, and directs  that a  cur-
 rent of phosphuretted  hydrogen shall  be passed into a
 solution of the chloride of gold.
   Phosphuret  of Iodine.  (Phosphure d'lode.)  Iodide
 of phosphorus.
   Phosphuret  of  Iron.   (Phosphure de Fer.)  Bluish
 gray, of a  granular fracture, brittle, unalterable by the
 air, without action  upon the  magnetic  needle ; decom-
 posable by nitro-muriatic  acid and charcoal.   It is ob-
 tained  by powerfully heating 4 parts of  the phosphate of
 iron with one  of lamp-black in a crucible with charcoal;
 if the charcoal is in excess, a mixture of the  phosphuret
 and carburet of iron will be obtained; this may be sepa-
 rated by muriatic acid which dissolves the  latter without
 attacking the former.   It  may be  prepared  by heating
 iron to redness in a porcelain  tube, and introducing the
 vapour of phosphorus.
   Phosphuret of Lead. (Phosphure de Plomb.)  Bluish
 white,  more brilliant than the metal, little ductile, less
 fusible than lead, decomposable at a high temperature :
the action of  the air transforms it into  the phosphate of
lead.   It is prepared by throwing small  pieces of phos.
phorus into lead  in a state of fusion.
   Phosphuret of Manganese.  (Phosphure  de Manga-
nese.)   Brilliant,  very brittle,  much more fusible  than
manganese ; without action upon the air at the ordinary
                         31* 
366
P H O
 temperature ;  it is obtained  in the same  manner as the
 phosphuret of iron.
   Phosphuret  of Mercury.  (Phosphure de Mercure.)
 Black, of little  consistence.  It  decomposes in contact
 with the air, diffusing phosphoric acid in white  vapours.
 It is  obtained by heating phosphorus under water, with
 the deutoxide of mercury.   Thomson denies the exist-
 ence of this phosphuret; he  considers the compound thus
 produced as an intimate mixture of phosphorus and mer-
 cury, or rather as the black oxide of mercury.
   Phosphuret of Nickel.  [Phosphure de Nickel.]  Bril-
 liant, brittle, more fusible than nickel, crystallizes in lit-
 tle annular prisms ; at an elevated temperature it is trans-
 formed into  a phosphate of nickel.   It  is obtained by
 passing the vapour of phosphorus  upon the metal heated
 to redness, or by decomposing a salt of nickel by phos-
 phuretted hydrogen.
   Phosphuret of Platina.  (Phosphure de Platine.)  Of
 a grayish white,  very hard, brittle, of  a granular texture,
 more fusible than the metal.  It decomposes at a high tem-
 perature.  It is prepared by subjecting to an intense heat
8 parts of phosphoric  acid with 8  parts of platina and 1
part of lamp-black.  Mr.   Edmond   Davy  admits  two
phosphurets of platina.  Platina having a great tendency
to combine with  phosphorus, it follows that platina cruci-
bles should not be used for preparations  containing this
 substance.
   Phosphuret  of Potassium.  (Phosphure de Potas-
 sium.)   Dark brown, of a sharp and  caustic  taste ;  it is
 easily reduced to powder.   Heated in the air, it absorbs
 oxygen gas and  becomes phosphate  of potash.  It de-
 composes water at the ordinary temperature, throwing off
 phosphuretted  hydrogen, which inflames  spontaneously.
 It is obtained by heating phosphorus and  potassium in a
 small retort. 
P H O
36^
  Phosphuret of Selenium.  (Phosphure de Selenium.)
Berzelius is the only chemist who has prepared this phos-
phuret.   Phosphorus  can combine with selenium in all
proportions.  It is very fusible, has a metallic brilliancy
and glassy fracture ; water decomposes it into phosphoric
acid and hydro-selenic acid.
  Phosphuret  of  Silver.    (Phosphure  d'Argent.)
More fusible than  this  metal.  White, brittle, granu-
lar ; it decomposes at a high temperature.  It is obtained
by throwing small pieces of phosphorus upon filings of
silver heated to redness.
  Phosphuret of Sodium.   (Phosphure de  Soude.)  It
possesses all the physical and chemical properties of the
phosphuret of potassium,  and is prepared in the same
manner.
  Phosphuret of  Sulphur.   (Phosphure  de  Soufre.)
Sulphur, like  selenium,  combines  with phosphorus in
many proportions, of course it may be  supposed that the
phosphuret of  sulphur varies much in its  properties:
sometimes  it is liquid, sometimes solid, of a yellow co-
lour, more  or less dark ; it is always  heavier than water.
If the temperature  is but little increased, it volatilizes:
oxygen gas decomposes it into sulphurous and phospho-
ric acids, with an elimination of light and heat; it inflames
by  contact with the  air.   Great precaution should be
taken in the preparation  of this  phosphuret, on account
of danger from its explosion.   To avoid this accident, the
substances should be heated under  water,  having  pre-
viously moistened the (lowers of sulphur that it may not
swim upon the surface ; the heat is raised  to about 140°.
and the mixture is stirred with a tube  in order to favour
the  combination.  Phosphuret of  sulphur can also be
prepared by melting phosphorus in a small glass tube, and
adding by degrees small  bits of sulphur; it  is necessary
to wait till each fragment shall have combined  before
adding another; a slight noise like that made by plung- 
308
P H T
ing hot iron into water gives notice  that the combination
has taken place.*  This phosphuret was discovered b\
Margraff, studied by Pelletier,  Thenard,  Faraday, and
many other chemists, whose labours are recorded in the
Journals of Chemistry and Physics.
   Phosphuret  of Tin.   (Phosphure d'Etain.)   In ex-
ternal  appearance resembling  silver;   it separates into
thin scales by the action of the hammer; when  fused,  i!
crystallizes  like  antimony into a resemblance  of fern
leaves : at a high temperature it absorbs oxygen gas and
becomes a  phosphate of tin.   This phosphate is a little
ductile ; for this reason Thenard  regards it as not satu-
rated  by phosphorus.  It is prepared by throwing small
fragments of phosphorus into melted tin.  (Pelletier.)
   Phosphurets of Titanium, of Tungsten, and of Mo-
lybdenum.   Scarcely known ;  it is only ascertained thai
they exist.
   Phosphuret of Zinc.   (Phosphure de Zinc.)   Bluish
white,  slightly malleable, decomposable  at  a great heat.
It  is prepared  by putting small  fragments of phosphorus
upon zinc melted  and covered  with resin to prevent its
oxidation.  A better  method of  preparing it is  to decom-
pose a salt of zinc by a current of phosphuretted hydro-
gen.   (Pelletier.)
   Photometer.   An instrument constructed  by Leslie.
he  supposing  that light, when  absorbed, produces heat.
One of  the bulbs  of his differential  thermometer  is
blackened ;  this when exposed  to the light,  becoming
warmer than the clear bulb, indicates the effects of the
depression of the fluid.
  Phtore.  A  name  formerly given  to the  supposed
base of fluoric acid; it is now called fluorine.

 * The authors state however that this process is not without danger, as on*
<>f them, in the use of it, had nearly fallen a victim to a violent explosion. 
P I c
369
   Physiology.   (From the Greek phusis, nature,  and
 logos, a discourse.)  The science which has for its ob-
 ject the knowledge of the phenomena of organic bodies.
 It  is divided into vegetable and  animal physiology;  che-
 mistry, so far as it investigates  the elements of organic
 matter, is a  branch of physiology.
   Picromel.  (From the Greek pikros, bitter, and megi,
 honey, so called  from its peculiar taste.)  A substance
 without colour,  of the  consistence of  turpentine,  of a
 nauseous  smell, a sharp, bitter, and sugared taste, of a
 greater specific gravity than water.  Exposed to the ac-
 tion of fire,  it decomposes and furnishes a few azotic pro-
 ducts.  It attracts moisture from the air and is insoluble
 in water and alcohol;  it is not precipitated from its solu-
 tion by the acetate of lead, infusion of nutgalls, or  the
 alkalies;  the sub-acetate of lead,  the  salts of mercury
 and iron, are the only agents which precipitate this  sub-
 stance.  Picromel treated with acids at a mild  heat be-
 come a viscous mass, almost insoluble in water.
  Picromel exists in the bile of man, the ox, and probably
 in that of all animals.   It is usually prepared by pourino
 into the bile of  the ox, neutral acetate of lead, which pre-
 cipitates a yellow and resinous matter, and sulphuric and
 phosphoric acids.  The liquor contains all the picromel;
 this is  filtered and mixed with the sub-acetate of lead ; it
 forms  a flosculous precipitate composed of the oxide of
 lead and picromel; this after being washed with many-
 waters is  dissolved  in diluted acetic  acid;  a current of
sulphuretted  hydrogen is passed into  the solution; this
 precipitates the  metal  in the state of a  sulphuret;  it is
 then only necessary to filter and heat  the liquor in order
to vaporize the acids,  and obtain pure  picromel.  Ac-
 cording to Thomson, this substance consists of
           ^      Carbon,    53-54
                   Hydrogen,  1-82
                   Oxygen,   45*65
It was  discovered by Thenard. 
0/0
P  L A
  Picrotoxine.   Picrotoxia.  Solid,  transparent,  bril-
liant ; crystallizes in quadrangular  prisms, its taste is in-
supportably bitter.  Submitted to the action of fire, it acts
like  the resins;  it gives no ammoniacal  products.   It
easily dissolves in alcohol; boiling water dissolves ^V and
cold water TL of  it.   It exists in the  fruits of the Meni-
spermum cocculus.  According to Orfila it is of a nature
so deleterious that the smallest quantity will destroy ani-
mal  life.
  Piperine. (From piper,  the Latin  name for pepper.)
Solid, transparent, insoluble in cold water, hardly soluble
in boiling water ;  but dissolves in ether and alcohol.   It
is procured by treating pulverized black pepper  with
boiling alcohol, filtering  and evaporating the solution  to
dryness.  The brown mass  resulting  from the evapora-
tion  is  treated with  water, and the part  not dissolved is
afterwards treated with  boilin.> alcohol, which dissolves
all the piperine ;  on cooling, it crystallizes in elongated
prisms.  It is purified  by many times repeating the pro-
cess.
  Pipette.   A glass bulb with which are connected two
little glass  tubes, one of which  is  bent and  the  other
straight. This instrument is used for decanting liquids; the
straight end is introduced into the liquid; at the other end
the operator sucks with the mouth, until the bulb is nearly
filled with the liquid, the aperture is then closed with the
tongue, the pipette is withdrawn from the liquid  and its
contents discharged by the  straight tube  into the vessel
destined to receive it.
  Plaster of Paris.   See  Sulphate of Lime.
  Platina.   (Platine.) This metal was so called by the
Spaniards from the word plata, silver,  which it resembles
in colour ; or from the river Plata, near which it is found.
Platina is a solid metal of a silvery whiteness^ery ductile,
very malleable;  it is so soft that it may be cut with scissors,
or scratched with the nails;  it is unalterable by the  air at 
P L A                   371
 all temperatures.   It is the heaviest substance known in
 nature ; its specific gravity is 20-98; it is infusible at the
 most  intense heat of the  furnace ; it has never been
 fused  but by the gas bkw-pipe.   It unites to metals  and
 forms alloys ; among combustible non-metallic bodies, it
 has been combined only with boron,  sulphur, phosphorus,
 chlorine, selenium, and iodine. This metal, like palladium,
 possesses the property, when in the spongy state, of in-
 flaming hydrogen gas at the ordinary temperature.
   Platina ore is found in nature combined  with the four
 new metals iridium, rhodium, palladium, and osmium, and
 also iron and chromium.   The ore of platina is in flat
 grains ;  the largest piece of platina  known, weighed one
 pound and nine ounces : this was  discovered by a negro
 slave, in the  gold  mines  of Condoto.   Platina ore has
 been seldom found except in America. The places where
 it  has  been  most common are Peru, Carthagena,  and
 Brazil.  Vauquelin discovered it in silver ore from Spain.
 in which, it constituted one  tenth of the metal.
   Platina was first  discovered  by Wood, an assayer in
 Jamaica, in the year 1741 ; but Don Antonio Ulboa first
 described its existence, in the narrative of his voyage to
 Peru, with the French academicians. Most chemists have
 studied the properties of this metal; rhodium and palla-
 dium were discovered in it by Bergmann, Lavoisier, dec ;
 iridium was discovered in it by Descotils, and osmium by
 Tennant.  Various processes for the  extraction of platina
 have been described.   Those  who  may wish  to learn
these   methods are  referred to the works of Thenard,
Vauquelin,  and  Wollaston.  As the newly discovered
metals iridium, rhodium, dec, exist in the ore of platina,
the process for obtaining the former are connected with
 that of extracting the latter metal.
   The property of platina to resist the most intense heat,
and the action of the  most powerful acids, renders this
substance very precious in the arts; in chemistry it is 
372
POL
used  for  retorts, crucibles, capsules,  and tubes ;  it i-
used for the evaporation of sulphuric acid, dec.; but un-
fortunately this metal is still too rare to be of use in do-
mestic economy.
  Plomb.   See Lead.
  Plumbago. (Plombagine.) (Fromplumbum, lead.) Black
lead.   A  name  given in the  arts to the per-carburet of
iron.   It is an ore of a shining blue colour, greasy to the
touch. It is chiefly found in primitive rocks. In mineralo-
gy it is called graphite.   It is used in the manufacture of
black lead pencils and crayons.
  Pluranium.   Recently discovered by  Osann.   It is
obtained from platinum, and is a grayish coloured metal.
It forms an oxide and sulphuret; its farther properties are
not known.
  Pneumatic  (From the Greek pneuma, wind;  relating
to air.) Of, or belonging to air or gas.
  Poison.  (Poison,  French; Venenum, Latin.)   This
name is given to substances which, taken internally or
applied externally, derange the vital functions, producing
serious accidents, and even death.   We have been care-
ful in describing each poisonous substance to remark upon
its venomous property,  and  to point  out the  principal
agents by which its presence  may be detected. To those
who would wish to investigate the subject more fully, the
learned treatise  on Toxicology of Professor Orfila is par-
ticularly recommended.*
  Pollenin.  The pollen  of tulips has been ascertained
by Professor John, to constitute a peculiar substance, in-
soluble in alcohol, ether, water, oil of turpentine, naphtha,
or carbonated and pure alkalies ; it  is extremely com-
bustible, burning with great rapidity and much flame, and
hence used  at the theatres to imitate lightning.

  * Toxicology includes the study of the nature of poisons, their mode of opera-
tions and antidotes. Most writers on poisons have drawn their facts  chiefly
from the treatise above recommended. 
POT
373
   Polychroite. A red pulverulent substance, of a slightly-
bitter taste, inodorous, colouring the saliva yellow.  It is a
little soluble in cold water, more so in boiling water; is
dissolved by alcohol and ether, also  by the alkalies and
fixed and volatile oils.  Exposed to heat, it acts like vegeta-
ble substances.  Vegetable acids dissolve one part of the
polychroite; the solution, by the addition of an alkali, pre-
cipitates all the  colouring matter.  Nitric acid gives  it a
green colour, which disappears on diluting it with  water,
and re-appears by a new quantity of the same acid ; sul-
phuric acid at first  communicates to it a blue colour; it
then passes to a violet;  chlorine entirely deprives it of
colour.  This substance is obtained by treating the aque-
ous extract of saffron with alcohol at 104° ;  evaporating
three fourths of the  liquor, mixing a little potash and soda,
in order  to separate the essential oil, pouring in acetic
acid to saturate the alkali, and washing the residue with
many waters.
  Pompholix.   A name formerly given to  the oxide of
zinc   (See this word.)
  Potash.   Protoxide of potassium.   (See this word.)
  Potash Vitriolated.  Some ancient chemists gave
this name the sulphate of potash.
  Potassium.   A solid metal, very ductile, lighter than
water, softer than wax,  of a steel gray colour;  when
newly  cut, it has great metallic brilliancy.   It tarnishes
easily  on exposure to the air, becomes bluish, and soon
changes  into a  white protoxide commonly called pot-
ash.   When heated in contact with  oxygen  gas,  the
absorption is  instantaneous; much  caloric  and light
are disengaged, and the result  is a deutoxide of  potas-
sium.  Atmospheric air, at  the ordinary  temperature,
acts upon potassium like oxygen gas ;  but in proportion
as the  metal oxidates,  it absorbs carbonic  acid from  the
air, and passes to the state of a proto-carbonate.   Potas-
sium heated in  a small  retort, with the oil  of naphtha.
                         32 
374
POT
fuses at 138° ;  at a temperature a little elevated,  it sub-
limes, diffusing green vapours.   Boron and carbon have
no effect upon potassium ;  it is the  same  with nitrogen,
in a phial of which, notwithstanding the combustible  na-
ture  of that metal, it may be preserved.  There does how-
ever exist a combination of nitrogen, ammonia, and po-
tassium.
  If potassium is  heated in close  vessels with a little
phosphorus, the result will be a phosphorus of a brown
chestnut colour, easy to be  reduced to powder, and with-
out any metallic appearance.  Sulphur acts upon potas-
sium like  phosphorus, producing a reddish yellow  sul-
phur.  Iodine,  aided by heat, unites to potassium with a
great elimination of light and caloric,  producing a white
iodide of a pearly appearance.
  By moderately heating potassium in hydrogen gas,  and
gently agitating it,  a gray hydruret without a metallic
appearance is formed.   According to  M. Sementini,  hy-
drogen can unite to this metal in two other proportions,
producing proto and deuto potassuretted hydrogen gases ;
it is with  respect to these gases as with the proto  and
deuto phosphuretted hydrogen ; the first of them inflames
only at the approach of a burning body, while the second
inflames spontaneously;  in  both cases there is a forma-
tion  of water and the protoxide of potassium.
  When potassium at the ordinary temperature  is  agi-
tated in chlorine,  much  caloric and light are  disen-
gaged ; the chlorine is solidified, forming a chloride of
potassium, similar in all respects to the saline compound
known as the febrifuge salt of Sylvius.   All the gaseous
hydracids  are  with heat decomposed by potassium;  it
abstracts  their base  in  order to  form a  chloride, an
iodide, or a sulphuret of potassium ; hydrogen is disen-
gaged.   Potassium also  decomposes  the  anhydrous* or
L Anhydrous signifies without water. 
POT
375
 gaseous acids; it  takes oxygen from water, sometimes
 disengaging the base ;  but with boracic acid it forms
 boron and a sub-borate of potash ;  with phosphoric  acid
 it  forms phosphorus and the phosphuretted protoxide of
 potassium.
   One of the most important  properties of potassium is
 the facility with which, at the ordinary temperature, it
 decomposes water.   If some fragments  of potassium
 are thrown  into a vessel  of water, action immediately
 takes place, the metal rises to the surface of the water,
 which decomposes  with a slight explosion.-  So much
 caloric is disengaged,  that the hydrogen gas resulting
 from the decomposition of the water  is inflamed; the
 water which remains, contains the protoxide of potassium
 in solution.
   We are indebted to Sir H. Davy for the discovery  of
 potassium; previously potash had been  considered  as a
 simple substance.
  Potassium may be obtained by the  following process :
 a piece of potash, having a small cavity filled with mer-
 cury, is placed upon a metallic plate ;  the  positive pole
 of the  voltaic pile is brought in contact with the plate,
 and the negative with the mercury;  as soon as the  pile
 commences action,  decomposition takes place ; the mer-
 cury solidifies; it is then put  into the  oil  of naphtha;
 new mercury is placed in. the cavity of the potash ;  the
 potassium is  separated from the mercury by distilling it
in a very small retort with  the  oil of naphtha.   By  this
process only a very small quantity of potassium can be
obtained with a great degree of labour.  The following
is  a more simple manner of obtaining  potassium : if a
thin piece of solid hydrate of potassa be placed between
two discs of platinum, connected with the extremities of
a voltaic apparatus of  200 double plates,  four  inches
square,  it will soon undergo fusion; oxygen  will sepa* 
370
PRE
rate at the positive surface, and small metallic globules
will appear at the negative surface ; these are potassium.
  Gay-Lussac and Thenard, in 1810, discovered a more-
expeditious mode of procuring potassium, by heating iron
filings to whiteness in a curved gun-barrel, causing melted
potash to be slowly brought into contact with the iron, air
being excluded; potassium is formed and  collected in
the  cool part of the tube.   For more particular directions
with respect to this last process, the reader is referred to
Thenard's " Traite de Chimie."
  Potassium is employed in chemistry in order to absorb
oxygen from some bodies which cannot  be deoxidized
by any other means.  Both by analysis  and synthesis
potassa is proved to be a compound of oxygen, with the
peculiar inflammable  base potassium.
  Potassuretted Hvdrogen.   (Hydrogine  Potassie.)
A name given by Sementini to a gas which is obtained by
treating at a high temperature, the hydrated protoxide of
potassium with iron filings, as in the extraction of potas-
sium.  The existence of this gas seems doubtful; if it
does exist, it is but ephemeral.
  Potential Cautery.   Caustic potash.
  Powder.   (Poudre.)   See Gunpowder.
  Precipitate  White.  (Precipite   Blanc.)  A namr
formerly given  to a  precipitate which was obtained by
pouring a solution of  common salt into the nitrate of mer-
cury ;  a precipitate was  formed, which  was washed, in
order to separate the nitrate of soda, and the  corrosive
sublimate, which always in a greater or less quantity, was
formed during this operation.  See Proto-chloride of mer-
cury.
  Precipitate Per  Se.  Red Oxide of Mercury by heat.
  Precipitate Purple of Cassius.   Chloride of Gold.
  Precipitate Red. (Precipite Rouge.) A name given
to the deutoxide of mercury. 
PYR
377
   Precipitation.  (Precipitatio, from precipito, to cast
 down.)  When two bodies are  united, for instance, an
 acid  and an oxide, and a third body is added such as
 an alkali, which has a greater affinity for the acid than the
 metallic oxide  has,  the consequence  is, that the alkali
 combines with the acid, and the  oxide thus deserted, ap-
 pears in a  separate state at the  bottom of the vessel in
 which the  operation is performed.  This decomposition
 is commonly known by the name  of precipitation, and
 the substance that sinks, is named a precipitate.  The
 substance,  by the addition of which the  phenomenon is
 produced, is denominated the precipitant.
   Principles.  (Principia.)  Primary substances.   Sub-
 stances or particles which are composed of two or more
 elements; thus  water, gelatine, sugar, fibrine,  dec, are
 the principles  of many bodies.   These  principles  are
 composed of elementary bodies, as oxygen,  hydrogen,
 azote, dec, which are undecomposable.
   Prussiates.   Before the discovery of cyanogen, the
 compounds which  we have  described as cyanides and
 hydro-cyanates, were termed prussiates.   They are salts
 formed  by the union of prussic (hydro-cyanic)  acid,  or
 the colouring matter of prussian blue, with a salifiable
 basis.
   Prussic Acid.   See Acid Hydro-Cyanic.
   Prussine.   Prussic Gas.  Cyanogen. (Seethis word.)
   Pyrometer.   (From the  Greek pur, fire, and metron
 measure.)  An  instrument  for  measuring  degrees  of
 heat, to which the thermometer cannot be applied.  The
 most  celebrated  instrument of this  kind, is  Wedge-
 wood's.
   Pyrophorus.   (Pyrophore.)   A chemical combination
 which possesses the singular property of inflaming spon-
taneously when in contact with the air.  It is said to  be
composed of sulphuret of potassium, of alumine, and a
finely powdered carbonate.  It was discovered by Horn- 
378
P Y R
berg.  Tthis  chemist having  been  engaged  in some
analyses with various substances, was surprised some
days afterwards, when on taking from a cold  retort the
caput mortuum of one of his  mixtures, to see it immedi-
ately take fire ; he recollected that this residue, was that
of a  mixture of alum and animal matter which he had dis-
tilled.   He repeated the process and obtained  the same
result.   When assured of his success, he published his
discovery, which was repeated by many  chemists.  For
a long  time  they scrupulously followed  the process  of
Homberg ; but Lemery demonstrated that for the animal
matter, sugar, honey, farina, dec, might  be substituted.
At present pyrophorus is prepared  by  mixing  3 parts of
alum, based on potash, with  1 part of sugar or  molasses,
drying the  mixture  over the fire in an  iron pan, till it
begins to  burn;  it must be  carefully stirred during the
operation ; it is then pulverized, and a phial or matrass is
about three quarters filled, and covered with a tube ; this
phial is placed in the furnace, gradually surrounded with
burning charcoal; it is heated until a blue flame, which
appears in the neck of the phial, begins to disappear ; the
the phial is then withdrawn from the furnace,  closely
stopped, and left to cool.  The pyrophorus may be pre-
served a long time  if kept from contact with the air.  It
is well made, if on pouring a very little upon paper it  in-
stantly takes fire ; but if it only heats the paper or takes
fire  with difficulty, it is not  good.   Damp air favours  it>
inflammation.
   Pyro-Tartrates. Combinations of pyro-tartaric acids
with bases.  These salts are little  known ; like  all ve-
getable  acids, they are  decomposable  by  fire;  they
cannot support an elevated temperature without being  re-
duced to their elements.   The pyro-tartrates of soda,
ammonia, lime, barytes, and strontian, are very soluble ;
the first is even deliquescent, resembling much the acetate
of potash, differing however  in this  respect, that the 
Q U  I
379
latter is not precipitated by the acetate of lead, while the
pyro-tartrate of potash produces with it an abundant pre-
cipitate.


                          a.

   Quadroxalate Of Potash.  See Acid Oxalate  of
Potash.
   Quicksilver.  See Mercury.
   Quinine.   A muddy white substance, not crystalline.
little soluble in boiling water,  and still less so in  cold
water ;  it is soluble in alcohol and ether.   Its vapour is
that of  the  quinquina.   The essential  and volatile oils
dissolve a small proportion of the quinine.  Exposed to
the action of heat it fuses at 194° ; if the heat is continued.
it  decomposes like vegeto-animal  substances ; it under-
goes no  alteration by exposure to the air; it  possesses
alkaline  properties,  restores  the  blue colour of litmus
paper when reddened  by an  acid;  it saturates acids,
producing white salts, which crystallize easily.   Quinine
exists in the yellow, red, and gray quinquinas,  (peruvian
bark,) combined with kinic acid. In the yellow  quinquina
this vegetable alkali exists in the greatest abundance.
   Quinine was discovered by Pelletier and Caventon.  It
is obtained  by decomposing  with heat, the  sulphate  of
quinine  by  magnesia; the quinine is deposited  and re-
mains mixed  with an excess of magnesia; it  is treated
with alcohol, which dissolves all the quinine; this on
cooling, is precipitated ;  it is purified by a second time
dissolving in alcohol.  According to  the analysis of Pel
leticr, it is composed of carbon 75
                  Azote     8-45
                  Hydrogen  6-66
                  Oxygen  10-43 
380
R  E A
                         R.

   Radical.   That which is  considered as constituting
 the  distinguishing part of an acid by its union with the
 acidifying principle, or oxygen which is common to  all
 acids ;  thus, sulphur is the  radical of the sulphuric and
 sulphurous acids.  It is sometimes called the base of the
 acid, but base is a term of more extensive application.
   Rancidity.   The  change which oils undergo by ex-
 posure  to the air.
   The  rancidity of oils is probably  an effect analo-
 gous to the oxidation of metals.  It  essentially depends
 on the combination of oxygen with the extractive princi-
 ple,  which  is naturally united with the oily  principle.
 This inference  is proved  by attending to  the process
 used to  counteract or prevent the rancidity of oils.
   Re-agent. (Reactif.)  Synonymous with test.  Such
 bodies are termed re-agents, as when brought in contact
 with other unknown bodies, form with them combinations,
 whose characters serve to point out the unknown  body,
 or at least, to indicate its nature.  All bodies,  simple  or
 compound, may be employed as re-agents; since all, when
 simple can form combinations, or when compound can be
 separated from  their combinations to  form new  ones,
 when the  sum of the forces which retain them, is less
 than the sum of the forces  which tend to form  new com-
 pounds.  Although the term re-agent might thus  be applied
 to all substances, its application is usually confined to such
 as are commonly used in  chemical analyses.   Many of
 these substances possessing analogous  properties,  pro*
 duce singular effects  with most  of  the  substances  to
 which they may  be presented;  we are to choose among
 these, that substance which has the greatest affinity for
 the substance sought for, or which forms with it combina-
tions having the greatest cohesion.  Other circumstance^ 
REA
381
 being equal, those re-agents should be selected, which are
 the cheapest, and may be most conveniently employed.
 These considerations reduce chemical re-agents to a com-
 paratively small number.  We shall, in this article, treat
 only of such  as are  most commonly used ; those who
 wish for more extensive information, are referred to the
 Treatise on Re-agents (Traite des Reactifs)  of MM. Che-
 valier and Payen.  It  is from this work that most of our
 remarks on the subject will be  selected.
   Acetate of copper (acetate  de cuivre) precipitates gold
 from its solutions to a metallic state ; it is also employed
 for ascertaining the quantity of sulphur contained in  mi-
 neral waters.
   Acetate  of lead {acetate  de plomb) forms  with  boracic
 acid  a borate insoluble with water, soluble without effer-
 vescence in nitric acid, and fusible by the blow pipe into
a colourless glass.  It  precipitates carbonates and sub-
carbonates white ; the  precipitate is  heavy, soluble with
effervescence in nitric  acid.  It also  precipitates phos-
phates ;  the  precipitates  upon  burning  coals  give an
odour of  phosphorus.   Like the  acetate of copper, it
forms a  sulphuret in solutions  containing  sulphur, and
can of cqjirse  be  employed in the  analysis  of mineral
waters.  It precipitates almost  all  colouring matters.
It serves to separate almost all vegetable acids which form
an insoluble salt;  it precipitates tartaric acid and does
not precipitate hydro-tartaric acid.   It is employed  for
ascertaining  the purity of  citric acid ; if the precipitate
contains no sulphate, it will dissolve in acetic acid.   It
detects foreign colouring matter in wines ; such wines as
are coloured by the elder and campeachy wood, it preci-
pitates a deep blue ; such as are coloured by  sandal wood
or  the red beet, it precipitates red;  and precipitates
greenish  gray,  such as are coloured  naturally by the
grape. 
382
R E  A
   The subacetate of lead is employed in much the same
 circumstances as the neutral acetate.  It precipitates the
 picromel from bile ; it precipitates animal mucous matter
 in flakes, and does not precipitate gelatine.
   Acetic acid is'sometimes employed as a substitute for the
 acetate ; it  serves  to neutralize certain salifiable bases,
 when it is wished to retain the salt in the liquid.
   Arsenious acid, (acide arsenieux,) or  the  deutoxide  of
 arsenic,  precipitates  sulphuretted hydrogen  in a yellow
 sulphuret, giving an odour of garlic  when thrown upon
 burning coals.   It precipitates lime water ; united with
 potash, it precipitates the solutions of copper green.  All
 its precipitates when thrown upon  hot coals give the
 same garlic-like odour.
   Carbonic acid is employed  for detecting the quantities
 of lime, barytes, and strontian, contained in liquors :  an
 excess of this acid is introduced into the liquors to be ex-
 amined, it is heated in order to precipitate the carbonate
 which is formed ; these precipitates dissolve with effer-
 vescence in nitric acid.  It precipitates white the sub-ace-
 tate of lead and  the precipitate  immediately  becomes
 black by contact with an alkaline hydro-sulphuret.
   Gallic acid colours the  solution of iron ; its*.colour  is
 deep  in proportion as the  iron is more  highly oxidated.
 It does not colour the  solutions of the  protoxides, unless
 in contact with the air at the same time ;  the acid employ-
 ed should be in excess.   It precipitates barytes greenish
 white ; does not precipitate strontian.  It precipitates the
 solutions of titanium orange red.
  Hydriodic acid precipitates the solution of platina wire
 red.
  Hydro-chloric (muriatic)  acid precipitates  silver from
 its solution in the state of a chloride  insoluble in nitric
 acid,  and soluble in  ammonia.  It precipitates the solu-
 tions of the  proto-salts of mercury; and does not preci-
pitate those of the deuto-salts, in which it forms a deuto- 
R E A
383
chloride (soluble corrosive  sublimate).  It discovers by
white vapours the presence of free ammonia in any sub-
stance whatever; it  is sufficient to present to this sub-
stance, a small tube or stick dipped in a solution of this
acid, in order to perceive the loss of very small portions
of ammonia through the lutes of an apparatus ; by am-
monia also,  the loss  of muriatic  acid  may be  equally
manifested.  This acid is employed to separate iron from
many metals upon which it does not act.
  Sulphuretted hydrogen, (hydro-sulphuric acid,) is em-
ployed to ascertain the nature of metallic solutions by the
colour of its precipitates ; these precipitates are almost
always sulphurets.

Thenard's  Table of the colour of precipitates formed by
      sulphuretted hydrogen, in metallic solutions.
Salts of the first two sections   .  .  .  not precipitated.
        manganese   .  .  .   .  .  .     do.
        the protoxide and deutoxide of iron do.
        peroxide of iron  ....   yellow.
        cerium.......not precipitated.
        cobalt   .  .  .  .  .  .  .     do.
        titanium    ......     do.
        nickel.......     do.
        zinc........white.
        deutoxide of tin (d'etain deutox.) yellow.
        protoxide of tin (d'etain protox.) chocolate.
        cadmium      .....   yellow.
        deutoxide of arsenic    .   .   yellow,
        chromium
        molybdenum
        columbium
        antimony      .....orange.
        uranium
        bismuth......   blackish brown*
        copper......   dark brown. 
384
R E A
 Salts of tellurium    .....orange brown.
         lead.......blackish brown.
         mercury......black.
         silver (d'argent.)   .  .   .  black.
         palladium
         rhodium
         platina......black.
         gold (d'or.).....black.
         iridium
   The nature of those precipitates which are of the same
colour, is determined ny other trials, and in these we are
assisted  by the knowledge  that the metal must be one of
those which give similar precipitates with  the re-agent.
   Nitric acid is  frequently employed to  separate the
metals little oxidable from those which it can dissolve,
in order  to distinguish iron from steel ;  it forms upon the
latter a black  spot.   It  precipitates a concentrated solu-
tion of the arsenite and forms no precipitate in an equally
concentrated  solution of the arseniate.   It entirely dis-
solves the deutoxide of  mercury, but does not completely
dissolve  minium or the red oxide of lead, leaving a brown
oxide more oxygenated than the former.   It shows the
presence of hydro-sulphuret, by precipitating the sulphur.
It is employed in many of the  chemical experiments
upon minerals.                    .
   Oxalic acid has so great an  affinity for lime that it
takes it from sulphuric  acid ; it  is therefore employed to
detect this substance.   It is employed pure or combined
with ammonia; it is used to separate  many metals mixed
in solutions.   Among these metals some form insoluble
oxalates, and others  soluble oxalates ; as for example,  in
a mixture of iron, titanium, ana* cobalt, the oxalates of the
last two are insoluble.   It forms with barytes a soluble
oxalate in an  excess of the acid, which is  not  the case
with strontian  ; when poured into wine which  is adulter-
ated with lead, it gives a precipitate  which when heated 
RE  A
385
 by a blow pipe in the cavity of a piece ot charcoal gives
 a globule of metallic lead.
   Sulphuric acid  precipitates  the  solutions of barytes,
 lead, and many other substances. The precipitate formed
 with solutions of lead gives with the blow pipe a metallic
 globule ,- that formed in solutions of barytes gives a yel-
 low flame ; that formed in solutions of strontian gives a
 purple flame.  It dissolves indigo without discolouring it,
 but does not act in the same manner upon the cyanide of
 iron (prussian blue.)   It  points out  most of the salts
 whose acids are volatile or little soluble.
   Albumen (albumine)  precipites in flakes  the mercu-
 rial  salts ; the precipitate  ought to give by combustion
 the mercurial vapour, which is easily known by the appli-
 cation of a plate of copper.
  Alcohol. This re-agent is employed almost as frequently
as water; its use is founded upon its property of dissolv-
ing  certain bodies which are insoluble in water; and
precipitating others by  uniting with those  which held
them in solution ; thus it is used in all vegetable analyses
to separate the products, to dissolve resinous matters, and
to separate  certain salts; for  example, the acetate of
 potash  from the  acetate of soda; the  last is insoluble in
 alcohol.
  Stairh  (amidon) shows  the  presence of iodine, with
 >vbich it forms blue mixtures.
  Ammonia (ammoniaque)  precipitates  copper from its
solutions, and re-dissolves  the precipitate, forming with it
a blue  liquor, which  soon covers with metallic copper a
[date of iron or  zinc, that is dipped into it.   It precipi-
tates zinc white, redissolves the precipitate ; it also pre-
cipitates iron but does not  dissolve the precipitate when it
is peroxidated.   It is employed to separate  iron from
manganese;  these metals  being brought to the state of
. hlorides are treated by this re-agent, which dissolves the
manganese while the iron remains in a solid state ; it i^
                          33 
386
R  E A
however better as respects precision to separate the two
metals by the succinate of ammonia.
  Barytes (baryte). The water of barytes forms precipi-
tates in many solutions, but is more particularly employed
to ascertain the presence of sulphuric and carbonic acids;
the precipitate  formed by the first of these  acids is inso-
luble in an excess of acid, very heavy and gives with the
blow pipe in the cavity  of a piece of charcoal a small
fragment of the  sulphuret of barium.  The precipitate
formed  by carbonic acid is easily known by nitric acid.
  Benzoate of ammonia  forms an insoluble benzoate with
the oxide of  iron, and a soluble benzoate  with those of
manganese, nickel, and cobalt.
  Borate of  soda  {borate de sonde). Heated by  the blow-
pipe with a metallic  oxide it  is coloured  differently ac-
cording to the nature of the oxide.  It forms with the
  Oxide  of chrome  ...  an emerald green.
           cobalt  .  .   .  deep blue.
           copper (cuivre)  bright green.
           tin  (etain) .   .  pale green.
           iron (fer)  .   .  bottle green or yellow.
           manganese .   .  violet.
           silver (argent)   yellowish.
           antimony   .   .     do.
  The  sub-borate  of soda is always employed in  the
analyses of gases  to separate  sulphurous and muriatic
acid, the latter of which it has the property of absorbing.
   Carbonate of ammonia precipitates the solution of alu-
mine, of glucina, and yttria, but  an excess re-dissolves
the last  two bases without attacking the alumine.
   Neutral carbonate of potash, when poured into a solu-
tion containing magnesia and lime, precipitates only  the
latter, if the solution  is cold.
   Sub-carbonate  of potash is chiefly employed with  the
 sub-carbonate  of soda to precipitate metals from their
 solutions. 
R E  A
387
Table of the precipitates  of different metallic solutions
   produced by the sub-carbonates of potash and soda:
Solutions of alumine
           silver (argent)
                           white flakes.
                           white, it blackens by the action
                             of light and sulphuretted hy-
                             drogen.
                           white, pulverulent, soluble in ni-
                             tric acid.
                           white, blackens by sulphuretted
                             hydrogen.
                           granulate, of a silver whiteness.
                           white.
                           violet.
            copper (cuivre) apple green.
            iron (fer) .  .   yellow or brown.
                           white.
                           white, pulverulent.
                           reddish white.
                           white, light, flosculous.
                           white, heavy, blackens by con-
                             tact with sulphuretted hydro-
                             gen.
                           white, heavy.
                           yellowish white.
                           white.
                           white.
                           white.
  Heat (chaleur) or caloric is much emnloyed in  chemi-
cal analyses.  When a mixture contains two substances of
which one at a certain degree of heat is volatile  and the
other fixed, it is evident that  it will be sufficient, in order
to separate  the  constituent  principles, to raise the tem-
perature of the mixture to that degree  which is necessary
to volatilize the one.   In  other cases heat renders solu-
ble in certain mediums substances which are insoluble in
the same medium without this agent, and which can be
separated on the cooling of the liquid. The  various ways
m which bodies are affected by caloric as to their fusion.
barytes .   .

bismuth

cerium .   .
lime (chaux)
cobalt  .   .
glucina .   .
yttria  .   .
manganese
magnesia  .
lead .  .   .
strontian
titanium
uranium
zinc .  .
zirconium 
388
R E  A
change of colour, diffusion of odours, volatilization, coloui
of their  vapour, decomposition, dec, often throw greal
light upon  their nature, and sometimes are alone  suflv
 ient to manifest their presence.
   Chlorine (chlore)  precipitates solutions of those hydro-
genated  bodies, in  which  hydrogen  is  united to a sub-
stance by itself insoluble in the liquid of the solution ; it
is the same as respects  the gases with gaseous chlorine.
It  decomposes  most vegetable and  animal substances,
particularly colouring matter, always by uniting with theii
hydrogen.   It precipitates solutions  of silver white ;  the
precipitate which is insoluble in  nitric acid and soluble
in ammonia, is a chloride.
   Chromate of potash (chrdmate de potasse) precipitates
the solutions of lead yellow or orange, those of  mercury
red, and those of silver purple.
   Cyanide of mercury  {cyanure de  mercure). Its solution
precipitates the  solutions of palladium yellow.
   Distilled water is  one of the substances most used
in analysis.  It serves to dissolve and to separate soluble
bodies from  those  that are not soluble ;  it is  used  for
diluting  solutions, to collect substances which adhere to
the  apparatus, filters, dec   Lime  water {eau de  chaux)
demonstrates by a white precipitate the presence of car-
bonic  acid in a liquid; by a  yellow, orange,  or  brick
coloured precipitate it shews  the  presence of the per-
chloride of mercury (corrosive sublimate.)  It precipi-
tates white, phosphates, oxalic acid, and the oxalates ;  the
appearance of the  precipitate, and the manner in which
it  acts with caloric,  serve to distinguish it.
   Ether, like distilled water and alcohol, has the  property
of dissolving many bodies, and is particularly employed in
vegetable analyses in order to separate the different princi-
ples ; it dissolves wax,  resin, and many other substances-
   Gelatine precipitates tannin from its solutions;  the
precipitate is flaky, and collects in an elastic  mass; it
also precipitates many metallic solutions. 
R E  A
389
                         TABLE
 Of the precipitates produced by gelatine in some  metallic
   solutions.   (According to MM. Payen and Chevalier.)
 Muriate of gold, (hydro-chlorate d'or,) a yellowish preci-
   pitate, abundant, soluble by an addition of water.
 \Titrate of silver, a milky precipitate.
 Nitrate of mercury, cheesy precipitate.
 Per-chloride of mercury, white precipitate.
 Proto-sulphate of iron, yellow flakes.
 Per-sulphate of iron, milky precipitate.
   Hydriodate of potash,  or iodide of potassium, (iodure de
■potassium,)  precipitates  the  solution of lead  a  brilliant
yellow, those of the peroxide of mercury red, those of
bismuth a chestnut-brown, and those of  silver yellowish
white; these  precipitates are iodides;  that of  silver is
not soluble  in ammonia  as most other combinations of
silver are.
  Muriate de barytes  (chlorure de barium) is  employed,
like the nitrate of barytes,  to  demonstrate the presence
of sulphuric acid.
   Muriate of strontian, or chloride of strontian, forms a
precipitate with sulphuric  acid, and  a soluble salt with
boracic acid ; it serves to separate these two acids.
   Muriate of potash, or chloride of potassium, (chlorure dc
potassium,)  forms in the solution  of tartaric acid a preci-
pitate of cream  of tartar ; it does not  form a  precipitate
with citric acid  ; it is the same with the sub-carbonate of
potash.
  Muriate of tin, or chloride of tin, (chlorure d'etain,) pre-
cipitates  blue, solutions  which contain  molybdic acid;
orange-yellow, solution of platina ; deep brown, those of
the per-chloride of mercury  and the  neutral solutions of
palladium;  it forms with tannin a dirty white precipitate.
   Muriate of gold, or  chloride of gold, (chlorure d'or,)
                           33* 
390
R E A
precipitates  brown the solutions of the proto-sulphate 01
iron, also forms a precipitate with the essential oils..
   Muriate of platina, or chloride of platina, {chlorure de
platine,)  precipitates yellow the  neutral salts of potash,
and does not precipitate the  neutral salts of soda.
   Cyanide of potassium (cyanure de potassium) is frequent
ly employed as a re-agent, and the ferro-cyanide of the
same metal still more so, in order to ascertain the nature
of metals  contained in solutions ; they form  in these
solutions precipitates differently coloured.


                           TABLE
Of the colours of precipitates  produced by the cyanides and
  ferro-cyanides of potassium in different metallic solutions.
Saline solutions of
Colours of the precipitates
  by the ferro-cyanide of
  potassium.
Colours of the precipitate?
  produced by the simple
  cyanide of potassium.
Zirconium,.....
Manganese,.....
Protoxide of iron,  . .
Deutoxide of iron, . .
Tritoxide of iron,
Tin,...... " .
Zinc,........
Cadmium,......
Antimony,......
Uranium,  ..„._-
Cerium, .......
Cobalt,.......
Titanium,......
Bismuth,......
Protoxide of copper,  .
Deutoxide of copper,  .
Nickel,.......
Lead,  ..-...._.
Deutoxide of mercury,
Silver,.......

Palladium,  .  , . . .
Platina.
Rhodium
G°ld,  - -
white or clear yellow.
white,........
white, abundant,  ...
sky-blue, abundant,  .
deep blue, abundant, .
white,........
white,........
white,........
white, ........
blood-red,......
white.
 frass-green.
 rownish red.
white,........
white,........
crimson,.......
apple, green,.....
white.
white,........
white becomes blue by
  the air.
olive-green,  ...
white,
dirty yellow.
orange, abundant.
bluish green, abundant
almost insensible.
white.
white.
white.
white.
yellowish white
white.
white.
yellow.
yellowish white

yellow.
white, soluble in an ex
  cess of the cyanide
white at first, becomes:
a beautiful vellow. 
R E A
39]
   Hydrogen  (hydrogene) is employed  in the analysis of
gases, in order to burn the oxygen which they contain.
and to determine the quantity.
   Iodine (iode)  serves to  show the presence of starch.
with which it forms  blue compounds.
   Metals possess a peculiar brilliancy and a property of ea-
sily becoming oxidated ; chemists avail themselves of these
properties in investigating  the nature of substances.  The
existence of sulphuretted  hydrogen with metals is de-
tected principally with silver; upon a plate of copper
may be discovered the presence of mercury, silver,  and
of  many other  metals; these  are afterwards examined
with new re-agents ; with a plate  of copper may be as-
certained  the presence  of iron, zinc, gold, &c  It is
often sufficient  to rub upon a clear metallic plate a pre-
cipitate which has been obtained in order to ascertain rte
nature by  the traces which it  leaves upon the metal.
Two metals,  as zinc and copper brought in contact,  con-
stitute the  voltaic pile, or galvanic battery, which  dis-
unites the elements of bodies having  great cohesion, or
whose elements have so  strong an affinity as to oppose a
separation  by any other chemical means.
   Nitrate of  silver (nitrate d'argent) forms a chloride of
silver, white, heavy, and curdled, in all solutions which
contain  chlorine,  hydrochloric   acid,   or chlorides.
This  precipitate is insoluble in nitric acid  and soluble in
ammonia.  It forms a yellow sub-phosphate of silver in
solutions which contain phosphoric acid and in the phos-
phates.  This phosphate  gives, with  the  blow pipe, an
odour of garlic  or  phosphorus.   The nitrate of silver
gives also a fine yellow colour to liquors which  contain
the oxide  of arsenic; but it is very  difficult  when the
liquor contains  little arsenic, to  collect  the  precipitate
which gives with the blow pipe the garlic smell observed
in the phosphates.   It colours black,  liquors which  con-
fain traces of sulphuretted hydrogen. 
392
R  E A
   Nitrate of barytes is particularly employed to demon
 strate the presence  of sulphuric  acid and the sulphates.
 Nitrate of mercury  (proto)  forms with ammonia a gray
 precipitate which heated  with a little lime disengages
 ammoniacal vapours.  Nitrate of potash, or saltpetre is
 employed for the separation of arsenic from its combina-
 tions.   It is melted with  the substance containing arse-
 nic ;  the whole is dissolved in  water and may be precipi-
 tated by the nitrate  of silver, the sulphate of copper, sul-
 phuretted hydrogen, &c  Nutgalls (noix de galle) ; an in-
 fusion of these is chiefly employed to ascertain the pre-
 sence of iron, solutions of which it colours  bluish  black,
 more intense  in proportion as the metal is more oxidated.
 When in the state  of a  protoxide  the colour is visible
 only by agitating it in the air.  This infusion precipitates
 solutions of osmium  a dark blue ;  it precipitates those ol
 titanium orange yellow ; those of silver white ; those of
 mercury orange ;  and those of uranium brown.
   Papers without sizing, and impregnated with different
 re-agents whose colour changes by various solutions into
 which they may be dipped, serve to indicate the nature of
 these solutions; of this kind are  litmus paper, curcuma
paper, and papers impregnated with the  acetate of lead,
 the nitrate  of silver, &c    Per-chloride of mercury, or
 corrosive sublimate,  precipitates  lime water yellow and
 ammonia white; it  forms  with albumen a flaky precipi-
 tate, especially if the liquor is heated.  Picromel precipi-
 tates white the sub-acetate of lead, but does not precipi-
 tate the neutral acetate.
   Potash. The aqueous solution when pure, at the tempe-
 rature of boiling water, dissolves alumine to jelly and does
 not dissolve the oxide of iron ;  it  forms in metallic solu-
 tions precipitates of hydrated oxides, differently coloured;
 it redissolves some when it is used in  excess. 
R E  A
393
                        TABLE
Of the  colour of Precipitates formed by pure Potash in
  metallic solutions.   (According  to MM.  Chevalier and
  Pay en.)
•Solution of Zirconium,  .   .   .   grayish white.
          Aluminum,  .   .   .   white, half transparent.
          Magnesium,    .   .   white.
          Nickel,   ....   apple green.
          Protoxide of iron,   .   green.
          Peroxide of iron,   .   red.
Gold,  .   .
Uranium,
Manganese,
Bismuth,
Cobalt,   .
reddish.
yellowish green.
reddish white.
white.
greenish white.
           Protoxide of mercury, black.
           Deutoxide of mercury, yellow.
   Succinate of ammonia  serves  to separate iron from
manganese ; when poured into a solution containing these
two metals, and when the iron is peroxidated, it forms a
succinate of iron which precipitates.   An excess  of the
succinate must be avoided.
   Sulphate of copper, (sulfate de cuivre,) forms with the
arsenites a green precipitate, and with arseniates a bluish
white precipitate.
   Proto-sulphate of iron  precipitates gold from its solu-
tions.
   Persulphate  of iron  precipitates blue, hydro-cyanic
(prussic) acid and the soluble  cyanides;  and black, the
solutions which contain gallic acid.
   Sulphate of soda forms in solutions of lead a white pre.
cipitate, which dried and  heated by the blow-pipe in the
cavity of a piece of charcoal, gives a metallic globule.
Tannin precipitates gelatine and albumen.
   Infusions or tinctures are very useful as chemical tests;
(he principal kinds are  as follows :   litmus or turnsol is 
394
RED
 reddened by an acid, and its purple hue may be restored
 by an alkali; but it is less active than other direct  alka-
 line tests.  Red cabbages and radishes furnish as delicate
 tests for acids as litmus, and still more so with respect to
 alkalies.  Brazil wood gives a red infusion  which turns
 blue by alkalies and yellow by acids.   Blue violets afford
 a delicate test  for  the  presence of alkalies  and  acids;
 sirup of violets,  being an  article used  in medicine, is
 sometimes more conveniently obtained, but  the simple
 tincture answers equally well.   Turmeric  or  curcuma is
 a  very delicate  test for alkalies; its natural  colour is
 yellow, it is turned to an orange red by alkalies.
   In  concluding the subject of re-agents it should be
 remarked, that it would not be proper to pronounce upon
 the nature ot a body, for example, of a  pure metal, by
 the colour of the precipitate, when only one re-agent had
 been employed ;  it  is necessary to repeat experiments,
 and not to decide upon the nature  of substances till they
 have been tested in  various ways.   A  profound  know-
 ledge of  chemistry,  and especially  much  practice  is
 necessary, before analyses  can be performed to any ad-
 vantage.
   Realgar.   A name formerly given to the red sulphu-
 ret of arsenic
   Receiver.   Receivers are chemical vessels which arc
 adapted to the necks  or beaks  of retorts, alembics, and
 other distillatory vessels, to collect, receive, and contain
 the products  of distillation.
   Reduction,  or Revivification.    This word  in its
 most  extensive sense, is applicable  to all operations by
 which any substance is restored to its natural  state, or
what  is  considered as such ; but  custom  confines it to
operations by which metals are restored to their metallic
state after they have been deprived of  it,  either  by  com-
bustion, as the metallic  oxides, or by  the union  of some
heterogeneous matters which disguise them, as fulminat 
RES
395
uig gold, lima cornea, cinnabar, and other compounds of
the same kind.  These reductions are also called revivi-
fications.
   Regulus.   Diminutive of rex a king, so called because
the alchemists expected to find gold, the king of metals,
collected at the bottom of the crucible after fusion.  The
alchemists gave, in general, the name of regulus to me-
tallic oxides reduced by means of fusion, because they
expected to find gold in the metallic products which they
obtained.   The chemists who succeeded them continued
to call thus their demi-metals, such as antimony, arsenic.
cobalt, &c.
   Resin.   (Resine.)  A solid inodorous substance, brit-
tle, semi-transparent, and heavier than water.  The resins
all  become  negatively electrified  on  rubbing ; none  arc
• •onductors of electricity.   Exposed to the action of fire,
they burn with a yellow flame and much  smoke.   Water
docs not dissolve the resins; they dissolve very  well in
alcohol, ether, the  essential and fixe'd oils, and the waters
of potash and soda.   All  the resins  are  unalterable by
the air ; concentrated acetic and hydro-chloric acids dis-
solve without  decomposing them; they can be precipi-
fated by diluting the water  of the solution.
  It is different with sulphuric and nitric  acids ;  the first
easily dissolves  the  resins, though at the ordinary tern-
perature they are little altered;  the  solution is viscous
and  transparent, and by the addition of  water it imme-
diately precipitates a resinous matter ; but if the  solution
is heated it becomes brown, disengages much sulphurous
gas, forms water, and deposites Charcoal.  If, before  be-
coming entirely black, it  is diluted with  water  and  the
precipitate treated with alcohol, artificial tannin  is pro-
duced.  Nitric acid decomposes the resins with violence,
much gas is disengaged ; the solution is  not affected by
uater, and gives by evaporation a residue which  may be 
396
RHO
entirely changed to artificial tannin by treating it a second
time with nitric acid.
   The resins are a vegetable product; they exude from
trees, through pores or incisions which are made to facili-
tate their discharge.   They  are  generally united to es-
sential oils, which  give  them their peculiar taste, and
render them soft.  Some are even fluid at the ordinary
temperature, as turpentine,  &c ; others are solid and
odorous, as the mastic, animated  resin, &c
   The resins are formed of a great proportion of carbon,
hydrogen, and a small quantity  of oxygen ; none con-
tain nitrogen.   Gay-Lussac  and Thenard found in 100
parts of the resin of the pine,
               Carbon,   .   .   75-944,
               Hydrogen,    .   10-719,
               Oxygen,   .   .   13-337.
   Retort. A  distilling  vessel,  having  for  its  neck a
long bent cylinder ; from its crooked form its name, re-
tort, has been probably given.   The upper part of the
retort is  called the vault, the cylindrical part the neck.
Some retorts have an aperture at the vault closed with a
p-lass  stopper, such are called tubulated retorts.
   Retorts are  of crystal, glass, platina, silver, iron, lead,
porcelain and  stone.
   Rheine. Of a yellowish orange  colour, without any
peculiar  smell; its taste is slightly bitter, and it is soluble
in ether  and alcohol.   It was first observed by Vaudin.
   Rhodium.   A solid metal, brittle, of a grayish white.
without  action upon  oxygen gas at any temperature :
specific  gravity is  11-000.   It does not dissolve in any-
acid, but may be oxidated by strongly calcining it in a cru-
cible with the nitrate of potash.   It has been combined
with sulphur and some metals.  It  has  only been dis-
covered  in the ore  of platina, and then in very small
quantities. 
SAL
397
   Riiubarbarix.  A name employed to denote the active
 principle of rhubarb.
   Rochelle Salt.   Tartrate of potash.
   Risr.   Red oxide of iron.


                         s.

   Sacciio Lactates.  A name  formerly given to the
 mucates.  See this word.
   Safety Lamp (Davy's.)  See  Hydrogen.
   Saffron of Mars  (Aperitive.)   Ancient name for
 the carbonate of iron.
   Saffron of Metals.  Preparation of antimony.  Sec
 Crocus Metallorum.
   Sal Alembroth.  Salt of wisdom.  A white, very vo-
 latile salt, obtained by subliming a mixture of equal parts
 of the deuto-chloride of mercury and the muriate of am-
 monia.
   Sal Ammoniac   Muriate of  ammonia.   So  called
 because it was found near the temple of Jupiter Ammon.
   Sal Ammoniac of Glauber.   Sulphate  of ammonia.
   Sal Glauberi.   Sulphate of soda, or Glauber's salts.
   Sal Gemme.  Native muriate of soda.
   Sal Martis.   Salt  of  mars.   Green sulphate  of
 iron.
   Sal Plantarum.   Salt  of  plants.  Sub-carbonate
 of potash.
  Sal Saturni.  Salt of Saturn.   Acetate of lead.
  Sal Tartari.   Salt of tartar.  Tartaric acid.
   Sal Vegetabilis.   Salt  of  vegetables.   Tartrate  of
 potash.
   Sal  Volatile.   Volatile salt.   Aromatic  spirit  of
 ammonia.
  Salifiable.  Having the  property of forming a salt.
The alkalies, and those earths, and metallic oxides, which
                        34 
398
SAL
have the power of neutralizing  entirely, or in part, ano
producing salts, are called salifiable bases.
  Saline.   (From sal, salt.)  Of a salt nature.
  Saltpetre.  Nitrate of potash.  (See this word.)
  Salts.  (Sets.   In  Latin, Sal.)  Salts  are the result
of the  combination of  acids with salifiable bases.  The
ancients understood the word salt in a very limited sense ;
as including only such crystalline substances which, like
common salt, (chloride of sodium,) were more or less sapid:
and of  course soluble in water.   Chemists at present
comprehend under the name of salts the immense number
of combinations which can  take place  between  all the
acids and all the  metallic oxides;  as between ammonia
and vegetable  salifiable  bases.   As there are  certain
oxides  which  sometimes  perform the part of an acid,
sometimes that of an  oxide; and as this  case  is very
common in the natural combinations which oxides form
among themselves, it follows that in certain salts we re-
gard as  acid the principle which  goes to the positive pole
of the voltaic pile ; thus the oxides of gold form salts with
some acids and combine equally with potash, with which
they perform the part of an acid, forming saline com-
pounds called orates.
  The formation of salts is in general easy in proportion
to the degree of affinity which the metal of the oxide has
for oxygen : now the oxide in a  protoxide being retained
more strongly  than that in  a tritoxide or a deutoxide, it
follows that the protoxides unite to acids more easily than
the oxides which are more highly oxidated.
  Salts may exist  with excess  of base, with excess of
acid, or they may be composed in such a proportion that
the quantity of the acid completely neutralizes the quan-
tity of the base;  the  last are  called neutral salts, the
second acid salts, and the first sub-salts.   (See Nomencla-
ture Chemical.)   A salt is commonly considered  as neu-
tral when it has no action  upon vegetable colours ;  but 
SAL
399
 this rule is not general, as whenever the acid of a salt
 has little affinity for the base, the  salt, although neutral,
 is seldom without  action upon colours.  It cannot then
 be affirmed that a salt is neutral until its composition is
 known.
   The salts have been divided into genera and species;
 in attempting to study them without order, we should be-
 come  confused  in their  great variety of characters and
 properties.  Many useful  classifications of these sub-
 stances have been made.   Fourcroy divides the salts into
 genera according to the acids which compose them ; thus
 he named  sulphates (sulfates)  all the combinations of sul-
 phur with  salifiable  bases, &c ; he designated the spe-
 Wcs by adding to the name of the genus the name of the
 base with which the salt was  formed;  thus he gave the
 nams sulphate of iron {sulfate defer) to the combination
 of sulphuric acid with the oxide of iron.  Thomson on
 the contrary took  for the genera the name of the base,
 and for the species the name of the acid; thus instead of
 the term sulphate of iron he used  iron sulphated.  This
 last classification  has been rejected except in minera-
 logy ;  and  perhaps even here  ought to be abandoned on
 account of the analogous crystallographical characters pre-
 sented by each series of salts  containing the same acid.
   One of the principal reasons for preferring Fourcroy's
 .-lassification is  the  composition of the salts which are
 formed by  the same acid.  All the  salts of the same ge-
 nera, at the same  point of saturation, contain such pro-
 portions of the acid and the  oxide that the quantity of
 oxygen and  of  the  oxide  is  in proportion  to the quan-
tity of the  acid,  and  often to the quantity of the oxygen
of the  acid.   As a result of  this  law, the  quantities of
the salifiable base which unite  to an acid to  form one ge-
 nus of salts are in the same  proportion  as  those which
 •mite to another acid to form another genus of salts;  of 
400
SAL
 course in mixing two neutral salts capable of being  de-
 composed, the result is new salts, which are also neutral.
   Thus the composition of a salt of any particular genus-
 being known, it becomes easy to calculate  the composi-
 tion of all the other salts of this genus  by knowing  the
 composition of their  oxides;  and if the  quantity of acid
 and oxide which constitute a salt are known, it is easy to
 calculate  the quantity of oxygen contained in that quan-
 tity of oxide.   It is in this way that chemists are able to
judge of the composition of the oxides of magnesium, of
 zirconium, of aluminum, &c, although they have never
 been able to obtain their metals.  It is according to these
laws and the knowledge of the composition of a salt, that
 a decision can be made with respect to its being neutral,
although it reddens litmus or greens the infusion of vio-
lets.  The physical characters of the salts are very  va-
riable, and  their chemical  characters are  not less so;
some general properties may however be pointed out.
  If salts are exposed to the  action of  caloric,  whose
acids are not volatile, and which have much  affinity  for
the bases, they  experience no alteration;  most of the
others  are decomposed;   many volatilize;  almost  all
melt at first in  their water of crystallization, and after-
wards experience the igneous fusion.  If exposed to  tho
air, some attract moisture and liquefy;  others, on  the
contrary, part with their water of crystallization and  be-
come efflorescent; the greatest part experience no alte-
ration.
  In considering the action of water upon salts, they
might be divided into two grand divisions, viz., soluble and
insoluble;  but  it would be impossible  to  define  their
boundaries; indeed, strictly speaking, few salts are ab-
solutely insoluble, since all  are more soluble in hot than
in cold water, and many can be crystallized on cooling.
Water which is  saturated with one  salt can still dissolve
others, but in a smaller quantity; this property has been 
SAL
401
 applied  to the purification  of some salts.  All the salts
 based upon potash, soda, and  ammonia, are soluble in
 water.   It is the same with all the acid salts, except in a
 few cases; as the tartrates, which, being soluble in the
 neutral, are less so in the acid state.  Their solubility de-
 pends much on their cohesion, which often neutralizes in
 a degree their affinity for water.
   If into a saline solution is plunged a metal which has
 more affinity for  oxygen  than the  metal  which the  salt
 contains, there will be a decomposition, and  the  latter
 metal will be substituted  for the other, which will be de-
 posited on its surface.   By the contact of the two metals
 is thus formed an element of the  voltaic  pile, which ac-
 celerates the decomposition.
  Acids often decompose  salts to unite with their bases ;
the other acid is then left free ; this action will take  place
at the ordinary temperature if the acid employed is  much
stronger than the salt.  At an  elevated  temperature a
decomposition will  always take place whenever the acid
employed is undecomposable and not volatile at that tem-
 perature, while the acid of  the  salt employed  possesses
 opposite qualities ;  that is, when it may at a high tempe-
 rature be decomposed  or volatilized.  If an hydracid i?
 employed and decomposition takes place, the salt will
 not only be decomposed, but the acid employed, and the
oxide of the salt  will also be decomposed, producing wa-
ter, a chloride, iodide, &c, according as hydro-chloric,
 hydriodic acids, &c, have been employed. .
  When into a saline solution  is  poured a solution of
another salt, and an insoluble salt is formed, the decom.
 position takes place immediately ;  but if the two salts are
soluble,  the  decomposition  does not take place;  or at
least is not apparent until the liquor is evaporated.   Then
the less  soluble salt will first form  and crystallize •  but
during the course  of  the operation it may happen that
another salt will be deposited, whose crystallization would
                         34* 
402
SAL
require a different temperature, and thus salts of a dif-
ferent kind would be  obtained.  Certain  insoluble salts
may also  be decomposed  by soluble salts, but the result
will always be an  insoluble salt.   The action will con-
tinue until the degree of  saturation of the  liquids is in
equilibrium with  the force of cohesion of the insoluble
salt; of course this decomposition does not depend upon
the general laws of composition, which govern the soluble
salts.
  There  are  in  nature many salts;  the insoluble are
most abundant: sometimes  they are deposited in exten-
sive beds, as the  sulphate  of lime, {gypsum);  sometimes
they form whole mountains, as limestone, (carbonate of
lime,) phosphate of lime, &c. :  sometimes they are found
in veins, as the  sulphate  of barytes, phosphate  of lead,
carbonate of  copper, &c  Such as  are  soluble  arc
found in an efflorescent state, as alum, the nitrate of pot-
ash, (saltpetre,) and carbonate of soda; or in solution in
water,  as  the  sulphate of soda, magnesia, iron, copper.
dec   Salts are obtained by  various processes ; the four
following are the  principal:
  1st.  By combining directly with acids, oxides, or the
sub-carbonates;  when sub-carbonates  are  employed,
there is usually an effervescence and disengagement of
caloric.   2d.  By treating metals with acids ; it is neces-
sary to employ acids  so diluted that the salt can dissolve
as fast as it forms.  3d.  When they are insoluble, they
are obtained by double decomposition.  4th. When they
are sub-salts,  as they are  usually insoluble, they may be
procured by carefully pouring into the solution of a neu-
tral salt a small quantity of  potash or soda.
  Salts Acid.   Salts, with excess of acid.   See Salts.
  Salts  Double.  The  double  salts generally result
from the  union of two bases with  an acid; these were
formerly  called triple salts.  All  the salts possess the
power of uniting to form double salts; but  those which 
S  A L
403
tend more  especially to this are the ammoniacal salts ;
next those based upon potash and soda.  Almost all the
double salts contain  one of these three bases;  they arc-
usually less soluble than the salts which constitute them :
and the quantities of oxygen of the two bases are always
in simple ratio between them.
   Salt Common.  (Sel Gemme, French.   Sal Gemma,
Latin.)  The  chemical name for  common  salt  was
formerly muriate of soda. After the discovery of chlorine,
it  was termed the hydro-chlorate  of soda; but  since,
potash, soda, &c, by the discovery of Sir  H. Davy, are
found to contain a metallic  base, we  must again change
the name  of common  salt  to that of chloride of sodium,
(chlorure de sodium).   This substance is found in masses
in the bosom of the earth, and then called rock salt.   Its
colours are sometimes very brilliant, owing to the various
substances with which it is found combined ; it is always
transparent, and received its ancient name of gem, on ac-
count of its resemblance to precious stones.   It is usually
found associated with sulphate of lime and argillite.  It is
sometimes  obtained from  mines in a pure  state; when
mixed with any foreign substance, it is purified by being
placed in pits, and saturated with water ; the water is then
drawn out by means of a pump, and  evaporated.  Much
of the salt of commerce is obtained from the evaporation
of natural waters,  which contain the  chloride of soda in
solution.
   Salts of Epsom.   Sulphate of magnesia.   In  com-
merce this name is often  falsely applied to the  sulphate
of soda whose crystallization  has been disturbed.   It is
easy to distinguish them, by pouring into their solution,  a
^mall  quantity of potash  or  soda, which  produces no
action in the true Epsom salts.
   Salt of Lemons.   Super-oxalate of potash.
   Salt Marine.  See Salts.  Chloride of sodium,
   Salt of Nitre.  Salt-petre.  Nitrate of potash. 
404
SAP
  Salt of Opium.   Narcotine.
  Salts  of Rochelle.  Rochelle   sails.   Tartrate oi
potash and soda.
  Salt of Soda.   (Sel de  Soude.)  Sub-carbonate of
soda.
  Salt of Sorrel.   Acid oxalate of potash.
  Salt of Tartar.  Name given to the sub-carbonate
of potash, and sometimes to the acid tartrate of potash.
  Santaline.   The colouring matter of  the red sandal
wood.  This wood is obtained in  the East Indies, and in
some of the South sea islands ; it is the product of a plan*
whose  generic name is  Santalum, derived from the Arabic
wood zandal; in French the word is called santal; in En
lish, sandal, and sometimes sounders wood.  According to
Pelletier, this is a red solid substance ; it fuses when ex-
posed to a heat of more than 212°, decomposing like resins,
to which in many respects, it bears a resemblance.  It
scarcely dissolves in water, but is very soluble in alcohol,
ether, acetic acid, solutions of potash, soda, and ammonia.
Chlorine discolours it, and  converts it  into a  yellow
matter, which  retains muriatic  acid.  Sulphuric  acid
chars it.   Most of  the salts  poured into  alcoholic  solu-
tion, produce coloured precipitates.  Santaline is obtained
by treating successively powdered red sandal wood, with
boiling alcohol; on evaporating the alcohol, the santaline
is obtained pure.
  Saponification.  (From Sapo, soap.)  Our article on
this subject will be  extracted chiefly from the researches
of Chevreul, into the nature of fat  substances; until the
investigation of this laborious and learned chemist,  very
little was known upon  the subject.  By  the term saponi-
fication is  to be understood the changes  which fat sub-
stances experience in their equilibriums, by the action of
an  alkali.   This equilibrium being destroyed,  the ele-
ments of these substances combine  in other proportions.
giving rise to acids which combine with the adjacent 
SAP
405
alkalies, and form real salts.  There is also the formation
of a peculiar substance, not acid, called glycerine.   (See
this word.)
  Two principal causes thus  concur to produce saponifi-
cation.   1st. The influence of an alkali.  2d. The nature
of  a fat substance, of which the  one of its elements,
having a strong affinity for salifiable bases, shall consti-
tute as much as half the fat substance.  It maybe easily
conceived that fat substances exist which do not contain
sufficient oxygen to permit the formation of an acid, and
therefore, that  with them the process  of saponification
cannot take place; this is the  case with cholesterine.
Fat substances then will saponify better in  proportion as
their compounds contain acid principles.   This may be
observed in stearine,  elaine, (oleine,)  phocenine,  and
butyrine, in  which  acids constitute  at least 92 parts in
100, while glycerine makes up the remainder of the mass.
Potash,  soda, barytes,  strontian, lime, and  the  yellow
oxide of lead, convert the fat of pork into stearic, mar-
garitic, and oleic acids, and glycerine.
  It is remarkable that the oxides of zinc and  lead, which
are insoluble  in water, and give  rise to  compounds
equally insoluble, produce the same results as potash and
soda, which proves  that they have a very strong alkaline
power.  In considering saponification in a general manner,
it will be seen that the preparation of plaster with litharge
is a real process of saponification.  It is remarkable that
magnesia, which exhibits in most respects strong alkaline
properties, seems to change grease into soap, with much
more difficulty than the oxides  of lead and  zinc, which
appear much less alkaline  than  this salifiable base ; but
if  magnesia saponifies  grease  very slowly,  it presents
before completing  the saponification, the phenomenon
of a base, which  contracts with a fat not acid,  such a
union as to give rise to a homogenious compound, from
which the fat  cannot be insulated  even on exposure to 
106
S A T
boiling water, although in this  circumstance two causes
tend to produce a separation ;  1st, the difference of den-
sity ; 2d, the facility with which magnesia in a pure state
imbibes water.   Alumine  adheres  to the  grease less
closely ;  it is separated by boiling water.
  The salifiable bases  have then three ways of acting
upon grease : 1st, they convert it into glycerine, stearic
margaritic, and oleic acids; such are potash, soda, ba-
rytes, strontian, lime, the oxides of lead and  zinc, mag-
nesia, and ammonia, the last two act very slowly ; 2d, they
contract  a union, or  rather an adhesion, with grease,
without its undergoing  any change, as has been observed
with respect to magnesia before saponification; 3d, they
form no sensible union ; such  are the bases which, hav-
ing been carefully mixed  with grease,  separate when
the mixture is put into boiling water.  (Chevreul's Re-
searches into t.ie nature of fat  substances.)
  Saturation.   A substance is said to  be saturated
with another substance when it will dissolve  no  more of
it.  The degree of saturation varies by  caloric which
separates the molecules, and pressure which brings them
nearer.  Thus water which would be saturated  by any
particular salt at the common  temperature, would not be
so at a more elevated temperature, because the molecules
being thus separated would admit those of the salt to pass
in between them.   The capacity of saturation then in-
creases in proportion as the substance is heated.  There
are a few solid bodies which  form an exception to this
rule.   Common salt (chloride  of sodium) does not sensi-
bly dissolve in a greater quantity of hot than cold water ;
lime is precipitated by heating water with  which it is
saturated.  Pressure produces in solid bodies an inverse
effect to that of-caloric, but in the gases it increases the
capacity of saturation.  Thus water, which at the  ordi-
nary temperature and under the ordinary pressure, would
be  saturated by a volume of gas equal to its own, would 
S A V
40?
be able by a strong pressure or by lowering the tem-
perature (if it did not congeal) to dissolve a much greater
quantity of gas, and to contain 2, 3, 4, 5,  or more times.
its volume.  See Attraction.
  Saturn.  A name given by  the  ancient chemists to
lead, in allusion to Saturn, who devoured his children,
because lead combines with various metals,  or devours
them.
  Savons.  See Soaps.
  Savonule.   (Saponule.)  A name given to combina-
tions  of the essential oils with salifiable bases; these
combinations have been little studied ; they are very fee-
ble and cannot take  place but with the most energetic
salifiable bases.
  Sebates.  They are little known.  Those  of potash.
soda, and ammonia, are soluble.   Their solution  is de-
composed by most strong acids, which precipitate the
sebacic acid.   The sebates of lead,  mercury, silver, and
probably of most other metals, are not soluble in water.
  Seleniates.   According to Berzelius, it appears that
selenic acid can combine in four proportions with salifia-
ble bases, forming neutrd seleniates, acidulated seleniates,
acid seleniates,  and seleniates with an  excess of base.  In
the neutral seleniates the quantity of the  oxygen  of the
oxide is to the  quantity of the oxygen of the  acid in the
proportion of 1 to 2,  and to the quantity of acid as 1 to
G-959.   The acidulated seleniates, or bi-seleniates, con-
tain twice as much acid ; the acid seleniates, or quadri-se-
leniates, contain 4 times as much acid as the neutral sele-
niates.  The composition of the sub-seleniates is not known.
   The  seleniates are not decomposed by the  action of
fire, except when heated with a combustible body.   The
different combinations of selenic acid with potash, soda,
and ammonia,  are soluble in water;  the other seleniates
are not soluble, but become so  by an excess of acid.
Sulphuric acid, at the ordinary temperature, decomposes 
408                   S  E  L
 the  seleniates;  arsenic, boracic, and  phosphoric  acidn
 decompose them only with the aid of heat; these are the
 only acids which have been found capable of  effecting
 their decomposition.  The seleniates of potash,  soda,
 and ammonia are prepared  directly ; all the other neu-
 tral  seleniates are  obtained  by double  decomposition.
 The acidulated and acid  seleniates are obtained by com-
 bining directly a new proportion of selenic acid with the
 neutral seleniates.
   Selenite.  Native sulphate of lime.  (See this word.)
   Selenium was discovered by Berzelius and by him
 regarded as a metal; metals do  indeed exist  in nature,
 such as arsenic and  tungsten, of which there are no salts,
 and which can on the contrary form acids like the com-
 bustible non-metallic bodies; but  selenium,  joining to
 these properties  those of being  a very bad conductor of
 caloric  and electricity, we shall consider it  as a non-
 metallic  substance.   It is solid, insipid, inodorous, very
 brittle ; its specific gravity is 4-31.   If exposed to a tem-
 perature of 224°, it  fuses, and at a higher temperature
 volatilizes.  Its  vapour is deep yellow.   If instead of al-
 lowing it  to volatilize it is  cooled  quickly, it  presents a
 brown mass,  possessing a brilliancy and a glassy brittle-
 ness.  Its vapour suddenly cooled produces a red  pow-
 der resembling, except in colour, the flowers of sulphur.
   Selenium can combine with oxygen in two proportions
 forming an oxide and an  acid ; it also combines with hy-
 drogen, producing hydro-selenic  acid.   It forms com-
 pounds with sulphur, phosphorus, and most of the metals.
 Selenium has yet been found only in seleniuretted  cop-
 per,  and the cupreous seleniuret  of silver, minerals which
have been found but in two localities.   That obtained by
Berzelius was from the seleniuretted copper which exists
in the pyrites of  Falhun.
   Seleniurets (Seleniures.) Compounds having a great
analogy with sulphurets ; in their composition they are 
S E L
409
equally regulated by fixed laws ; thus the quantity of the
oxygen of a protoxide is to the quantity of selenium of
a proto-seleniuret, in the proportion of 1 to 4-854.  Like
the sulphurets, they are prepared directly, by introducing
into metallic solutions, a  current of hydro-selenic acid.
We shall, with Berzelius,  consider as seleniurets the com-
pounds which  result from the action of. hydro-selenic
acid with salifiable bases.  See Sulphurets.
   Seleniuret  of  Antimony  (Seleniure d'Antimoine.)
This, like the sulphuret of the same metal, is very fusible ;
when  heated in the air,  a transparent, vitreous scoria
rises to the surface ; this  seems analogous to the glass of
antimony.   Treated with hydro-chloric acid, it produces
a chloride of antimony and hydro-selenic acid.   It is ob-
tained directly.
  Seleniuret of Arsenic {Seleniure d'Arsenic.) Black,
very fusible ; it is obtained by gradually adding powdered
arsenic to melted selenium.   Combination immediately
commences; and  by a careful heat, either of the two
bodies which may be in excess, is expelled.  If the  heat
is raised to redness, the seleniuret boils, and produces the
per-seleniuret of arsenic;  there remains in the vessel a
liquid which cannot be volatilized but at a very high tem-
perature.
   Seleniuret of  Copper. (Seleniure de Cuivre.)   The
deuto-seleniuret of copper is obtained by passing a  cur-
rent of hydro-selenic acid into  a solution of the deuto-
sulphate of copper : it is precipitated in abundant black
flakes.
   Seleniuret of Iron.  (Seleniure de Fer.)  of a yellow-
ish gray colour, hard, brittle, and granular ; hydro-chloric
acid decomposes it, forming a proto-chloride of iron and
hydro-selenic  acids, a small  portion of which is decom-
posed and colours  the liquid red.
  This seleniuret, which  like the sulphuret, possesses a
metallic lustre which is  obtained by  heating in a glass
                          35 
110                    S  E R
 tube  selenium covered with  iron filings : light is discn
 gaged during the combination.
   Seleniuret of Mercury. {Seleniure de Mercure.) Is
 obtained by heating a mixture of mercury and selenium ;
 the body which is in excess volatilizes.   If the tempera-
 ture is a little more elevated, the seleniuret itself volatilizes
 and condenses in white scales in the upper part of the
 vessel.
   Seleniuret of Platina.  (Seleniure de Platine.) Pla-
 tina is one of the metals for which selenium has the great-
 est affinity ; thus the combination takes place at a  low
 temperature; notwithstanding this  affinity, this seleniuret
 is decomposed at red heat when  in contact with the air;
   Seleniuret of Lead (Seleniure  de  Plomb.)  Gray,
 porous, susceptible of polish  by rubbing, does not fuse
 easily.   Heated in oxygen gas, it absorbs it and produces
 a seleniate of lead.  It is obtained directly.
   Seleniuret of Potassium. (Seleniure de Potassium.)
 Of an iron gray colour, with a metallic lustre.  Its frac-
 ture is radiated, and exhibits  the  rudiments of crystals.
 It is soluble in water, and presents the same properties as
 the sulphuret of potassium.   It is obtained directly, with
 a disengagement of light and caloric.
   Seleniuret of Zinc  (Seleniure  de Zinc.)  Yellow,
 pulverulent;  it is obtained by bringing the vapour of se-
 lenium in contact with zinc ;  heated to redness ; there is
 always an explosion ; the seleniuret which is formed is in
 a very small proportion.
   Seleniuretted Hydrogen. See  Acid Hydro - Selenic.
   Septone.  One of the ancient names for azote or ni-
 trogen.
   Serum (From serus,  late, because it is  the remainder
 of the milk after the better part  has  been taken from it.)
Whey ; the yellow fluid  which separates from blood when
 cold and  at rest. 
S I G
411
   Signs Chemical.   (Signes Chimiques.)  The creation
 of chemical signs which at once indicate the name and
 the proportion of the elements which compose a substance.
 is to be attributed to Berzelius.   We shall  here  quote
 from his " Theorie des Proportions Chimiques."
   When we wish to express chemical proportions,we find
 it necessary to have chemical signs. They have longbeen
 employed,  although hitherto with little real advantage.
 When alchemy flourished, chemical signs were created.
 for the purpose of having a language mystical and in-
 comprehensible by the vulgar.  The antiphlogistic che-
 mists wished to substitute for these, others founded on the
 same principles as the  new chemical names.  The sign
 was to indicate the constituent parts of a compound body ;
 but although these signs were well chosen,  they were, it
 must be  acknowledged, almost useless ; for it is  more
 easy to write an abridged word than to delineate a figure,
 which, in order to be  understood, required to be larger
 than the ordinary  characters of writing.   In  proposing
 other signs, says  Berzelius,  I shall endeavour to  avoid
 these inconveniences.    I should, however, observe that
 these new signs are not created with a view of labelling
 substances in the laboratory, as the ancients did ; but it is
 intended by them to  ascertain the expression of chemical
 proportions, and to enable us to announce briefly, and with
 facility, the number of elementary atoms, which are found
 in every compound.   By knowing the relative weight of
 the atoms of simple bodies, we can, by means of  these
 signs, express the  result of every analysis, in a manner
 at the same time simple, and easy to be remembered.
  Chemical signs ought to be  alphabetical letters, that
they may be easily written and printed, and without dis-
 figuring the text.  I would select then for  this purpose
the initial letter of the Latin name of each simple body;
 but many of these  bodies having the same  initial, I will
 thus  distinguish them:  1st. The simple bodies non-me- 
112
S I G
 tallic (metalloides) shall be designated only by the initial
 letter, although even that letter shall be common to some
 metal.  2d. A metal, having the same initial as another
 metal or metalloid, shall  be designated by the first  two
 letters of its name ; or if they are found in another name,
 add to the initial the first different consonant;  for exam-
 ple, S = sulphur, SI = silicium, ST = stibium,* SN =
 stannum,f C = carbonicum, CO = cobaltum, CU = cu-
 prum,^: O = oxygenium,  OS = osmium.
   The chemical sign never indicates but one atom ; when
 it is necessary to express many, place a cipher at the left
 of the sign;  for example,  CU+O designates the oxidulc
 (protoxide) of copper; CU+20 the deutoxide of copper.
 But, in order to express an atom composed of the second
 order, according to the above method,  too long a formula
 would be necessary;  we would then abridge as follows :
 oxygen entering into  most combinations, and often by o
 number  of atoms, we would express this by points upon
 the oxidated radical, placing as many as there are atoms
 of oxygen in the oxide; for example, the oxide of cop-
 per protoxide = cv, and the deutoxide of copper = CU;
 sulphurous acid= s, and sulphuric acid = s ; this would
 show that  the oxidule  of copper contains 1  atom  of
 oxygen, that the deutoxide of copper and sulphurous acid
 each contain 2 atoms  of oxygen, and that sulphuric acid
 contains  3 atoms of oxygen.
   A salt  composed of two substances, for example, the
 sulphate  of the oxidule (protoxide) of copper,  would  be
 expressed by c U S ; and when there are in the compound
several atoms of one of the combustible bodies,  the num-
ber is expressed by  a little figure at the top and on the
right of the letter, as  in algebra; for  example,  C v  &
signifies  the sulphate of the oxide of copper, and indi-
cates that this salt contains 2 atoms of sulphur or sub
* Antimony.      f Tin.      + Copper. 
S I G
413
phuric acid.  This formula then shows at one view the
relation between the acid and the base, between the radi.
cals and between the  oxygen of the oxidated bodies.  I
have found, says Berzelius, that this method gives great
facility for  expressing  by  writing the composition of
bodies, according to the theory of chemical propor-
tions.
  It is equally easy to express by signs  the composition
of atoms of  the third order; for example, CA C2+M G
t;3  expresses the double mineral salt known by the name
of dolomite (chaux carbonatee magnesifere), which is com-
posed of one atom of the carbonate oflime, (carbonate de
chaux,) and  one atom  of the carbonate of magnesia.  If
several atoms of one of these substances enter into the
compound atom, the number of these atoms is marked by
a figure on the left;  for example,  the formula of alum
(kaline sulphate of alumine) is k S2 + 2al sh .
  In order to express the compound atoms of the fourth
order,  enclose  by parentheses each atom  of the third
order; thus, for example, the atom of crystallized alum
would  be expressed by (k'Si +2A LSb )-j-48H20, being
composed of one  particle  of the third  order combined
with 48 particles of water ; the atom of water might be
expressed by +A2, aqua being the Latin for water.
  With respect to organic bodies, their formulas, accord-
ing to  these rules, would in general be too complicated ;
however, in expressing the salts of many vegetable acids,
the  atoms of acid may be expressed by the initial letter of
its Latin name, with a mark to show that they are of inor-
ganic origin ;  for example, c = citric acid, T = tartaric
acid, a = acetic acid; and when different acids have the
same initial letters,  they may be distinguished by the
same method as that pointed out for the metals.  It may
be seen how much this method of expressing the compo-
sition of bodies abridges  labour, showing at  first glance
the  name of a compound, its proportions,  and the rela-
                         35* 
Ill
S I L
tions which exist  between these proportions  in the com
pounds of the second and third order, &c
  Silex.  See Oxide of Silicium.
  Silicium.   Silicon. Berzelius is the only chemist who
has succeeded in  insulating the base of silex.  We shall
therefore quote from his memoire, published in the Annals
of Chemistry^ vol. XXVII. page 341.  This chemist states
that silicium is of a nut brown, without metallic brilliancy,
of an earthy appearance ;  that it burns neither in the air
nor in oxygen,  bearing even the flame of the blow pipe
without any alteration ; it has never yet been fused.   Si-
licium presents this unchangeable character, only  when
very pure ; if it contain a little hydrogen and be heated
to redness, the  hydrogen  will inflame  and  at the same
time the silicium.  Silicon adheres  strongly even  when
dry to the sides of the glass  vessels  in which it is pre-
served.   It does not conduct electricity.
  Silicium, when heated with the carbonate of potash,
burns easily, disengaging  much  caloric and  light;  it
forms the oxide of carbon, the mass taking  a black ap-
pearance, which it owes to the carbon  not  burnt.  Sili-
con burns at a low temperature more  easily with  the car-
bonate than with  the nitrate  of potash; the affinity of
alkali for silex seems necessary in order to  produce the
combination of silicium, which is not  manifested  with the
nitrate except when the temperature  is  sufficient to de-
compose the nitric acid ; and if the mass burned remains
black for some  time,  it  is because the new combination,
which is compact, protects the charcoal until it fuses.
  When a mixture of silicium and the hydrate  of potash
or soda is heated, there is, at a certain temperature, a
detonation and a combination of the two oxides,  (silex
and potash,)  and a  disengagement  of hydrogen.  Sili-
cium heated to  redness in the vapour of sulphur burns,
though with a less vivid  flame than  in  oxygen; except
with very pure silicium no combustion takes  place. The 
S I L                    415
 sulphuret is an earthy white substance; if thrown into
 water, it dissolves, disengaging  sulphuretted hydrogen.
 The silex formed dissolves  in water, which becomes a
 jelly by slight evaporation.   Where the sulphuret is with
 an excess of silicium  the same phenomena appear, and
 a deposite of silicium is obtained.  The siliciuret of po-
 tassium easily combines with sulphur at a  red  heat;  a
 double  sulphuret is formed which brought in contact with
 water dissolves it, producing probably the silicate of pot-
 ash and the hydro-sulphuret of potassium.   It is singu-
 lar that silex can dissolve in water in so great a  quantity
 when forming, and wholly lose this property by evapora-
 tion.   This astonishing solubility throws great light upon
 the formation of druses,  or collections  of silicious crys-
tals, which often exist  in  cavities of quartz, agate, and
many other minerals, cavities which are sometimes almost
filled  with  these crystals, and which contain a  quantity
of liquid exceeding their volume.
  Berzelius was  not able to combine silicium with phos-
phorus, but he combined it with chlorine, by heating it in
this gas.  The product is a  yellow  liquid when it con-
tains an excess of chlorine, but  otherwise  it is  entirely
 colourless.  Its odour resembles that of cyanogen ;  it
 reddens the  tincture of litmus, swims upon water, and
 usually dissolves  in  it, disengaging  hydrogen;   it  may
be dissolved in a  mixture of cold  fluoric  and  nitric
acids, disengaging nitrous gas.   In its state of combusti-
bility it dissolves in a solution of caustic potash, but  after
calcination all attempts to dissolve it are vain.
  Insulated silicium with difficulty combines with metals;
it appears to have the  greatest affinity for  platina ; their
union however cannot be  affected without the medium of
a third substance.
  Silicium is obtained by decomposing the double fluate
of silex and soda; this last containing more of the fluate
of silicon than  any other; this  is powdered and dried.
then with layers of potassium put into a glass tube closed 
116
S I L
 and heated, the silicium is reduced with a slight hissing
 and without any disengagement of gas, provided that the
 salt contains no water; this  mass is left  to  cool,  then
 treated with a great quantity of cold  water; when  this
 water is no longer  alkaline, hot water  is employed, and
 the mass is then boiled  with  new water.  Silicium thus
 obtained contains a little hydrogen and silex ;  the hydro-
 gen is driven off by a careful calcination, this renders it
 insoluble ;  even fluoric acid which dissolves silex has no
 effect upon  silicium thus calcined.   If however the sili-
 cium were not  pure, containing, for example, a little iron
 or manganese,  it would dissolve in acid, disengaging hy-
 drogen, and 100 parts of silex would  absorb 108-22 of
 oxygen in order to  pass to the state  of silex.  It may be
 seen, from what has been said upon silicium, that it ought
 not to  be placed among the metals ; even if by fusion it
 can take a metallic brilliancy, its other  properties, and
 particularly that of being a non-conductor of electricity,
 must be a sufficient barrier to its receiving a rank among
 metals.  It has been seen that it has no great affinity for
 oxygen.   It is perhaps possible to judge of the affinity of
 a simple body  for  oxygen by its tendency to  combine
with other bodies, and particularly by the affinity of its
 oxides for acids.   If this principle is admitted we should
 regard potassium  as the body which has perhaps the.
 most  affinity for oxygen  and  silicium  as one  of  those
 which have the least.   Although experiment has not per-
 fectly established this principle, the character of silicium
 adds a new degree  of probability to the hypothesis. Ber-
 zelius would place silicium with boron and carbon.
  Silver.   (Argent.)  A metallic substance, white, duc-
 tile, having great tenacity, fusing but at a high tempera-
 ture.   Its specific gravity is 10-39.   Its primitive form is
 the cube, its secondary forms are the octoedron and its
 modifications.  It  volatilizes when heated  in close ves-
 sels.   In contact with the air, it absorbs at a certain tern- 
S I L
417
 perature a small quantity of oxygen, which on cooling is
 disengaged.   It combines with sulphur, phosphorus, chlo-
 rine, and iodine ; its combination with iodine is remarka-
 ble in being  insoluble  in ammonia.  Sulphuric acid acts
 upon silver only when assisted by heat; but nitric acid
 dissolves it  at the ordinary  temperature.   Most other
 acids, even when concentrated, have no action upon it.
   Silver is often found  pure in a native state, frequently
 sulphuretted, alloyed  with other metals, and sometimes.
 though  not often, combined with chlorine.   Much silver
 is extracted  from the sulphuret of lead, and some from
 copper  pyrites.  The value  of silver is  so great that
 mines, though  containing it but in very small quantities,
 are  usually wrought.   When  the silver is found  in large
 masses, as in Mexico  and some other countries, it only
 needs melting in order to obtain it pure; but it is usually
 obtained from  the sulphuret by means of lead  or mer-
 cury ; when  the latter metal is employed,  amalgamation
 can  take place only as far as the silver is not in combina-
 tion. It must  then first  be brought to a metallic state;
 for this purpose it  is roasted  in furnaces with a certain
 quantity of common salt, (chloride of sodium,)  and the
 chloride  of silver is  formed.  The minerals are then
pulverized and put into vessels which turn  upon  an axis,
or a  kind of mill.  Mercury, water, and old iron  are then
added ;  these decompose the chloride, and  the silver be-
ing set free, combines with the mercury.  This amalgam
being subjected to pressure in bags  of a  close texture,
one  portion of mercury escapes;  the amalgam is then
put  upon  large wooden perforated  plates,  which  are
placed one above another over iron vessels; the  amal-
gam is at first lightly heated, the temperature is gradu-
ally raised, and the whole of the mercury flows down and
falls into the  iron vessels below.
   Silver Horned.  {Argent  Cornee.)  See  Chloride of
 Sih-er, 
118
S O A
   Silver  Fulminating.   (Argent  Fulminant.)   Sc
 Cyanates.
   Siphon.  A name given to a tube bent in such a man-
ner that  one branch is longer than the other.   Siphons
are sometimes made of glass, more frequently of metal;
they are used for transferring  liquids  from one vessel to
another; for this purpose the shortest branch is put into
the liquid; by sucking with the mouth at the other aper-
ture the air is drawn from  the siphon and the liquid im-
mediately rushes up the tube and  fills the vacuum.  If
the liquid is caustic, or of a nature that might render it
disagreeable  to  perform this operation with the mouth,
the liquid may be drawn by expelling the air from the
siphon by first filling it with water.
   Soap.   (In Latin, Sapo; French,  Savon.)  It  is the
product of saponification; it consists  of a  union  of the
stearates, murgarates,  and  oleates of soda or potash:
salts which are capable of combining with these sub-
stances in all proportions, and of being soluble in water;
they combine however in different quantities.   The soaps
of vegetable oils and  of  human fat  are  formed  of the
margarate  and oleate of potash or soda in variable pro-
portions.   They are hard, as these bodies contain more
of the margarate in proportion  to the oleate.   Soaps
made of the grease of pork, mutton, and  beef, in addi-
tion to these two salts, contain stearate, and are hard in
proportion as its quantity is greater.  Besides this  cause
of hardness, much depends upon the  base, viz. whether
it be soda or potash; the latter produces soft soap, the
former hard soap.  The stearate  of soda may be consi-
dered as forming the hardest soaps, and the oleate of pot-
ash the softest.   The hardness of soap is also increased
by exposure to the air,  and evaporation from any cause:
but soft soap based upon potash cannot be dried like soap
made with soda, and is  much more soluble, 
S 0 D
419
   The solubility of soaps is thus ascertained to depend on
 the nature of their alkaline base, and the fat with which
 it combines;   now  as  the stearines are  changed into
 stearic and margaritic acids, and  the elain (oleine) into
 oleic  acid, to  a  certain  degree the hardness of  soap.
 which will be  produced by each fat substance, may be
 foreseen;  it will  for this purpose  only be necessary to
 ascertain the  proportions  of stearine  and elaine  which
 they contain;  this can be known by their degree of fusi-
 bility.  Then by  adding to the  oils which form only soft
 soap with soda, a substance which abounds in stearine, a
 hard soap may be obtained.
   Soaps may be odorous or inodorous ; in the latter case
 their odour is due to the presence of a volatile acid ; such
 as the butyric, caproic, and capric acids, in the soap made
 of butter ; the phocenic acid in the soap made of dolphin's
 oil, and the hircic acid in the soap  of suets.  (Chevreul's
 Chemical researches upon fat substances.)
   Hard soap is made by combining caustic  soda with
 sweet oil or the fat of beef or mutton.   Soaps  based upon
 potash or soda, are the only kinds which are  used  in the
 washing of clothes.   The specific gravity  of soap is
 usually greater than  that of water.  Its taste is slightly
 alkaline.   When  subjected to heat, it fuses, swells, and
 decomposes.  The medicinal soap, {sapo amygdolinus,) is
 made with the oil of sweet almonds, and half its weight of
 caustic alkali.   Common or soft  soap  (sapo mollis) is
 made of potash (obtained from  leaching  common  wood
 ashes) and animal fat.   Spanish or Castile  soap (sapo
 durus) is made of oil of olives and soda.
  Soda.  (Soude.)  See Oxides of Sodium.
  Soda Vitriolated.  An ancient name of the sulphate
 of soda.
  Sodium.   The  discovery of  this metal, as well as of
potassium, was made byr Sir H. Davy ; it has been studied
with great  attention  by Gay-Lussac and Thenard ; our 
420
SOL
remarks upon it  will be  chiefly borrowed  from  them.
This metal has much analogy with potassium, both in its
properties and the methods  of obtaining it.   It is solid,
inodorous, soft, and ductile.  Like wax, it is of a lead gray
colour ;  its fracture is very brilliant;  its density is 0-972,
at the temperature of 59°.  It fuses when exposed to the
action of caloric  at  194°, and does not volatilize  at  a
much higher temperature.  When exposed in  oxygen
gas or very dry air,  it  is not like potassium, destroyed ;
it is only when fused in this gas, that it absorbs oxygen.
producing a yellow compound, which is a mixture of the
protoxide and the deutoxide of sodium.  Like potassium,
it decomposes water,  but without any elimination of light.
It does not combine  with hydrogen, but unites with most
other combustible bodies, and  even with nitrogen.   A
substance which  has so  great a tendency to form com-
binations, does not of course exist pure in nature; it is
very abundant in  combination with chlorine, in  the state
of common salt, (chloride of sodium) and exists in many-
other natural compounds.
  Solanine.  (Solania.)  A peculiar vegetable substance
which has been discovered  in the fruits of the garden
night shade, (Solanum nigrum,) in the leaves  and stems of
the bitter sweet (Solanum dulcamara,) where it exists in
combination with  malic acid.  It is  a white pulverulent
opaque  substance, with a pearly (nacre) appearance, a
very bitter taste, fusible at 212°, and  decomposable at  a
much higher temperature.*  Like the vegetable alkalies,
it is very soluble in alcohol, scarcely  soluble  in ether, the
essential oils,  and boiling  water.  It forms with acids
very  bitter  and  uncrystallizable salts.  M. Desfosses,
who discovered solanine, obtained it by adding  ammonia
to the filtered juice of the garden night shade ; this formed
a gray  precipitate which he collected upon a filter, and
which when washed, treated with boiling alcohol, and
evaporated, deposited the solanine. 
S P I
121
  Solutions.  (From solvo, to loosen.)  An intimate mix-
lure of solid bodies with fluids, into one seemingly homo-
genous liquor.   The dissolving fluid is called a men-
struum, or  solvent.   (For the distinction made by the
French between  solution and  dissolution, see  the latter
word.)
  Sorbates.  See Malates.
  Soude.   Soda.  See Oxide of Sodium.
  Spirit  Volatile.  (Sal ammonia.)
  Spar Fluor.   (Spath Fluor.)  Native fluate of  lime.
  Spar Heavy.   (Spath Pesant.)   Native  sulphate  ot
barytes.
  Spelter.  The zinc of commerce.
  Spirit Ardent.   See Alcohol.
  Spirit of Mindererus.  See Acetate of Ammonia.
  Spirit of Nitre.   (Foaming.)  See Nitrous Acid.
  SpiritPyro Acetic {Esprit-Pyro Acetique.) Pyro-ace-
tic acid; from acetum, vinegar, and the Greek pur, fire,
it being made by the agency of fire on acetic acid. It is a co-
lourless liquid, of a peculiar taste, and odour between that
of mint and bitter almonds. It boils at 138°, and does not
congeal at 50°.   It  burns  very easily, and mixes in all
proportions with  water,  alcohol, the  fixed and volatile
oils.   Cold sulphuric acid decomposes it without-forming
ether ; it  combines with sulphuretted hydrogen ; potash
has no sensible action upon it.  As the pyro-acetic spirit
dissolves camphor, it is used in pharmacy for dissolving
that which  enters into  anti-septic (anti-putrescent) vine-
gar.   It is  obtained by a  destructive distillation of the
acetates.
  Spirit of Salt.   Hydro-chloric or muriatic acid.
  Spirit  of Sulphur.  Sulphurous acid.
  Spirit  of Wine.  Alcohol.
  Spirit of Venus.   Acetic acid.
  Spirit of Vitriol.   Sulphuric acid.
                          36 
422                    S T  A
    Stalactites.   These  are  found  suspended fro/i
  caverns, being formed by the trickling of water charged
  with calcareous particles, gradually evaporating, leaving
  the particles of lime behind.
    Stalagmites.   (From the Greek stalagmos, a dropping
 or distillation.)  Formed in the same manner as  stalac-
 tites, except that they exist at the bottoms of caves,  and
 the former are suspended from the roofs.
   Starch.  (Amidon, Latin Amylum.)  This  is one of
 the principles most  abundant in vegetables ;  it exists in
 the seeds, roots, stems, and leaves.   When pure, it  is a
 white powder, insipid, inodorous, insoluble in  cold water,
 alcohol, and ether, but soluble in boiling water; this so-
 lution on cooling takes the form of a jelly;  hot sulphuric
 acid transforms starch into a sugared substance, capable
 of yielding alcohol  by fermentation ;  concentrated sul-
 phuric  acid  poured  upon starch, chars it;  nitric acid
 transforms it into malic and oxalic acids.
   Starch combines with iodine in different proportions :
 the colour of their compounds is  blue, varying in shades
 according to the proportions  of iodine ;  a  beautiful blue
 colour may always be obtained by treating starch with an
 excess of iodine, dissolving the compound with liquid pot-
 ash, and precipitating it by a vegetable acid.   According
 to Gay-Lussac and Thenard, starch is composed of
                43-55 parts carbon
                49-68  "  oxygen
                6-77  "  hydrogen.
 Saussure discovered a small quantity of nitrogen, which
 Berzelius was not able to find.
   Starch is usually obtained  by grating the roots which
contain   the fecula and washing  the  product  with  pure
 water.   Its specific  gravity being greater than that of
water is  soon  deposited.   Starch for  common domestic
purposes, is usually obtained from wheat, potatoes, indian
corn, &c  As starch forms the greater  part of flour, it 
S T E
423
is probably the principal  nutricious  substance  in bread.
It is of use in medicine.
  Stearates.  Stearic  acid  combines in many propor-
lions with salifiable bases ;  according to Chevreul, it can
form neutral  stearates, and acid or bi-stearates;  in the
first, the oxygen of the oxide is to the quantity of acid as
3 to 100 ;  and in the acid stearates, in the relation of 3 to
200.
   Stearate  of  Ammonia.   (Stearate  d'Ammoniaque.)
White, almost inodorous, of an alkaline taste; it sub-
limes in a vacuum.  If heated in a retort in contact with
the air, it decomposes, water  is formed, ammonia disen-
gaged, and a portion of the stearate mixed with an empy-
reumatic oil sublimes.   It is soluble in hot water, particu-
larly with a little  excess  of alkali ; and the solution on
cooling deposites the bi-stearate under the form of brilliant
scales.  It is obtained by putting hydrated and fused stea-
ric acid in contact with ammoniacal gas.  The absorption is
at first very rapid, and continues for a long time.   The
stearate of very dry ammonia is formed of 100 parts of
acid and 6-68 of base.
  Stearate of Barytes. (Stearate de Baryle.) White,
insipid, inodorous, fusible at a  moderate temperature ; it
is obtained by a direct  process, but the operation must be
carried on in  contact with the air, on account of the car-
bonic  acid which it contains.  It is composed of 100 parts
acid to 28-72 of the base.
  Stearate of Lead. (Stearate de Plomb.)  The neutra
stearate of lead is obtained by mixing in a boiling state,
two aqueous solutions of the stearate of potash and the
nitrate of  lead.  It is composed of 100 of acid,  and 41-84
of  the base.   The  sub-stearate of lead which is without
colour, friable, and  very fusible, is obtained like the pre-
ceding, substituting the sub-acetate of lead for the nitrate.
it is composed of  100 of acid and 85-18 of the base. 
124
S T E
   Stearate of Lime.  (Stearate de Chaux.)  Is obtained
by pouring into  a boiling solution of the chloride of cal-
cium, a boiling solution of the neutral stearate of potash.
It consists of 100 of acid and 11-06 of the base.
   Stearate of Potash. (Stearate de Potasse.) The neu-
tral stearate is in little spangles, or in large  scales, bril-
liant, transparent, of a  soapy touch, and  a slightly alka-
line taste;  100  parts of boiling alcohol can dissolve 15
parts of it.  It forms a mass on cooling, it also dissolves
in ether; but the last having a greater affinity for stearic
acid than for potash changes the composition of the salt,
dissolving more  of the acid than the base.  Water does
not dissolve the stearate of potash but at an elevated tem-
perature ; when employed cold, and in a small quantity
it forms with this salt a thick mucilage ; if used in suffi-
cient quantity, it charges this stearate into potash, which
is  dissolved, and an insoluble bi-stearate.   This neutral
stearate of potash is obtained by heating 2 parts of stearic
acid and 2 parts of potash in 20 parts of water ; the stearate
forms and is then purified by alcohol.  It consists of 100
of acid and 18 of the base.
   The bi-stearate of potash  is in little brilliant scales, in-
odorous, and of a soapy touch.  It does not fuse at 212° ;
cold water has no action upon it, but boiling water sepa-
rates a portion of its alkali, and the residue not dissolved
can form with boiling alcohol, a solution which on cooling,
is  reduced to a  bi-stearate of potash, which crystallizes,
and stearic acid which remains in the liquor with a por-
tion of the bi-stearate.   The bi-stearate of potash is  ob-
tained by pouring a boiling solution of the neutral stearate
into a  great quantity of cold water, collecting the precipi-
tate, and dissolving it  in  alcohol;  it crystallizes on cool-
ing.   It consists of lOOof the  acid and 8-97 of the base.
   Stearate of Soda. (Stearate de Soude.)  This salt in
in brilliant crystals,  or semi-transparent  scales, at first
tasteless in  the  mouth then alkaline.  It is soluble in 20 
S T E
425
 parts of boiling alcohol.   Boiling  sulphuric ether sepa-
 rates from it a  little stearic acid, which, however, retains
 u trace of  the  soda.  The stearate of soda  can solidify
 a great quantity of water ; it dissolves in boiling water.
 The neutral stearate  of soda is obtained  by heating to-
 gether a  mixture of 20 parts stearic  acid, 13 parts soda,
 and 300 parts of water, and treating  the product with
 alcohol.  This salt is formed of 100 of acid and 12-33
 of soda.   The bi-stearate of soda is white, insipid, inodo-
 rous, more fusible than the neutral stearate, insoluble in
 water, very soluble in alcohol.   The alcoholic solution
 reddens the tincture of litmus ; it becomes alkaline by the
 addition of a certain quantity of  water.  It is obtained by
 dissolving with heat, the neutral  stearate in a great quan-
 tity of water, leaving  the liquid to cool, and  treating  the
 precipitate  with alcohol.   It is  formed of acid 100  and
 base 6-01.  The stearates of potash  and soda enter into
 the composition of most kinds of soap.
   Stearate  of Strontian.    (Stearate de  Strontian.)
 White, inodorous, insipid, is prepared like that of barytes.
 It is composed of
                Acid  ...   100
                Strontian    -    19-54.
   Stearine.   A fatty substance, white, less shining than
 stearic acid, fusible at 111°, forms  acicular crystals.   It
 volatilizes in a  vacuum without being decomposed  ; it
 gains odour by  contact with the air; it burns like suet,
 but if heated in a  retort,  one part decomposes,  giving
 rise to different products not azoted ;  and  the other part
 volatilizes.   Sulphuric  and nitric  acid decomposes it.
 Such are the properties  presented by the stearine extract-
 ed from the fat  of beef,  pork,  and mutton ; that which is
 extracted from  human fat, differs chiefly, in not  giving
stearic acid by saponification.   Stearine is obtained  by
treating successively fat substances with alcohol,  which
dissolves more  elaine (oleine) than stearine.
                          36* 
426
S T R
            It consists of  9*454 oxygen,
                         78-776 carbon,
                         11-770 hydrogen.
  Steel.  {Acier, French  ; Chalybs, Latin.)  The proto-
carburet of iron,  presenting  nearly the same characters
as this metal.  It is susceptible of a very high polish ; if a
drop of nitric acid is poured upon steel, a black spot will
appear; this is owing to the  presence of carbon.  Very
small quantities of steel have  been found in nature ;  that
which is used in the  arts is usually prepared by  heating,
for a long time, iron in contact with powdered charcoal.
Among the several varieties of steel, that which  is  most
common consists  of 1000 parts of iron, 6 parts of char-
coal, and a small quantity of silicium.
  Stibium.   (From the  Greek stilbo, to shine.)  An an-
cient name for antimony.
  Stimmi.  (From the Greek stimmi.)   Antimony.
  Stone Philosopher's.  (Grand QZuvre.) A name given
by alchemists to  an imaginary preparation which was to
change all metals into gold and silver.
  Strontian.  (So called because it was first discovered
in a lead mine in Strontian in Scotland.)  See Oxide of
Strontian.
  Strontium.  The metallic base of strontian ;  its pro-
perties are scarcely known.   It resembles calcium, and
like  that  base has been obtained  only by means of the
voltaic pile.
  Strychnine.   A salifiable vegetable base, white, pul-
verulent,  of an  excessively  bitter taste.  If examined
with a microscope, it will be found to be composed of ma-
ny  small  prismatic  crystals.  It is scarcely  soluble in
boiling  water and ether, but dissolves well in alcohol
and the volatile oils. Exposed to the action of fire, it de-
composes, giving  off ammoniacal products.   It  unites
with acids, forming salts soluble in water, and susceptible
of crystallization.  These salts are sometimes  neutral. 
SUB
42^
sometimes acid, and sometimes with an excess of base.
It  is obtained  directly  by double decomposition.   The
strychnine  is found in different parts  of the strychnos, in
combination with igazuric acid: it  is usually extracted
from  the  seed of  the Strychnos nux  vomica, which also
contains a quantity  of brucina.  An infusion of the vo-
mica  nuts is  treated with magnesia ;  the precipitate
treated with weak alcohol,  which takes up the greatest
part of the  brucine,  it is afterwards treated by concen-
trated and boiling  alcohol, which unites with the strych-
nine,  and  deposites  it on cooling ;  it is purified by new
ervstallizations.  It is composd of
                Carbon .  .  .  78-22
                Azote   .  .  .    8-92
                Hydrogen .  .   6-54
                Oxygen  .  .   6-38
   It was discovered by  Pelletier and Caventon.
   Suber.  Cork, a vegetable substance,  from the Quer-
cus suber.
   Suberates.  These substances have been studied by
M. Bouillon-Lagrange ; according to him, those of potash.
soda, and ammonia, are very soluble ; most of the"others
are insoluble.
   Suberine.   A name given by Chevreul to the cellular
tissue of the cork tree, which changes to  suberic acid b;,
the action of nitric acid.
   Sublimation.   (From sublimo,  to raise, or sublime.)
A process by which volatile substances  are raised by heat.
 and again condensed in a solid form ; the vapours usually
 condense  in  the  upper part of the  vessel.   Fluids are
 said  to be distilled, and solids  to  be  sublimed; though
 sometimes both are  obtained in one  and  the same  ope-
 ration.  If the subliming matter concretes into a solid
 hard mass, it is commonly called a sublimate ; if into a
 powdery form, flowers.  Solids  condense more easily
 than fluids. 
128
S  li (i
   Sub-Salt.    (Sel-Sous.)   A salt having an excess of
 base, beyond what is requisite for saturating the acid, as
 a super-salt is one with an excess of acid.
   Succinates.    (From  succinum,   amber.)   Little  is
 known respecting these substances ;  that of potash is de-
 liquescent ; those of soda and ammonia are very soluble.
 They  are obtained  directly  by  double  decomposition.
 The succinnate  of ammonia is employed  to separate the
 oxide of iron from the oxide  of magnesia;  it does not
 precipitate the latter.  According to Berzelius, the quan-
 tity of oxygen of the oxide is to the quantity of acid as
 1 to 6-28.
   Sugar.  (Sucre.)  This name was formerly  given to
 all substances whose  taste resembled that of the sugar-
 cane and which  were not  very unlike in appearance  ; at
 present  we  limit the  term  to those  substances which,
 when brought in  contact with water  and a very small
 quantity of yest, produce alcohol.  The other characters
 may be variable  ; there are  therefore many kinds of su-
 gar.   The sugar obtained from the cane (Arundo saccha-
 rifera) is the most  important.  This  sugar when pure is
 colourless, inodorous, of an  agreeable taste ; its density-
 is  1-6065.   It  is  insoluble  in  half  its  weight  of cold
 water, and in all  proportions in boiling water ; susceptible
 of crystallization in rectangular  octoedrons whose pyra-
 mids are truncated near their  base;  these  crystals con-
tain  little of the water of crystallization.   In certain  cir-
cumstances sugar may lose its property of crystallizing:
 this takes place when its watery solution is kept for some
time  in  the air, exposed  to a heat of 158°; it then be-
 comes an uncrystallizable  sugar  known by the name of
 molasses, (melasse.)
  When exposed to  the action of fire, sugar swells, dif-
fuses a peculiar  smell  called the odour of caramel,  and
leaves an  abundant charcoal.  Sugar  forms but feebh
 combinations with  metallic oxides.   If lime, barytes, or 
S U G
429
strontian  are boiled with  sugar, they  become bitter,
astringent, and  uncrystallizable ;  by adding  a sufficient
quantity of an  acid to neutralize the oxide, the sugar
resumes its properties.  Sulphuric and nitric acids decom-
pose sugar;  nitric  acid changes it to oxalic acid.  Its
solution is not precipitated by that of the sub-acetate of
lead.   Although this kind of sugar exists in many plants,
it  is chiefly obtained from  the  sugar-cane,  the sugar-
maple, (Acer saccharinum,) and the red beet.  According
to Gay-Lussac, sugar  is in weight composed of
                   Carbon    42-47
                   Oxygen    50-63
                   Hydrogen    6-90
   Sugar  Candy.   (Sucre Condi.)  Crystallized sugar,
when pure is colourless, but is usually coloured in making.
   Sugar of Gelatine.  A name given by Braconnot to
a peculiar substance formed  by the  action of sulphuric
acid upon gelatine.  This substance does not yield alco-
hol by fermentation ; it consists of  groups of hard gra-
nular crystals;  they crack under  the teeth,  and have a
sugared taste.   If exposed  in a retort  to the  action of
heat, they fuse  at  first and then decompose, forming a
white sublimate and ammoniacal  product.   They  are
soluble  in water and  insoluble in alcohol ; nitric acid
changes them to a peculiar  acid which Braconnot called
nitro-saccharique.
   Sugar of Grapes.  {Sucre de  Raisin.)   This offers
properties  similar to the sugar of the  cane; it differs
from it in  not crystallizing regularly, in being  less soluble
in cold alcohol, and in having a taste of sugar  less strong,
as it requires twice as much as the sugar  of the cane to
sweeten the same quantity of water.  This sugar exists
ready formed in many fruits,  and  can  be obtained by
treating starch  and other  analogous  substances  with
water and sulphuric acid.  It is  usually extracted by 
130
SUC
saturating with the carbonate of lime the expressed juice
of the grape.  According to Saussure, it consists of
                  Carbon     36-71
                  Oxygen    56-51
                  Hydrogen   6-78
   Sugar of Lead.   (Sucre de Plomb.)   See Acetate of
 Lead.
   Sugar of Milk.   (Sucre de Lait.)   A peculiar sub-
stance obtained  from milk, and which when  brought in
contact with water and yest does not produce alcohol; it
is not  therefore  a true sugar.   It is  a  solid, inodorous
substance, having a  sugared taste, heavier  than water,
capable of forming  semi-transparent crystals;  concen-
trated  alcohol cannot  dissolve  the sugar of milk; it is
therefore used as a test for  detecting the presence of this
 substance, with which the sugar of the cane is sometimes
 adulterated.  It is obtained by evaporating whey (le petil-
 lait) ;  it deposites in compact layers, which  are purified
 by new crystallizations.  According to  Gay-Lussac and
 Thenard, it consists of
                  Carbon    38-825
                  Oxygen   53-834
                  Hydrogen  7-341
   Sugar of  Mushrooms.   (Sucre de  Champignons.)
 White, has not the pleasant taste of the sugar of the cane.
 It is obtained by pounding mushrooms in a marble mortar,
 diluting  the pulpy  substance  with  water,  filtering  the
 liquor, evaporating  it,  and  treating  successively with
 alcohol the brown mass which is formed.  It crystallizes
 in elongated four-sided prisms.
    Sugar of Starch.   (Sucre d'Amidon.)  Starch made
 into a paste and left to  itself for  some time produces a
 certain quantity of sugar.  Sulphuric acid converts starch
 into sugar; if a mixture of water, starch, and sulphuric
 acid is boiled for a certain time, the acid will not be de-
 composed ; for if carbonate of lime is added, it will unite 
S U L
433
with it, and form sulphate of lime.  Saussure found that
the weight of sugar formed was  considerably more than
the weight of the starch employed; that  100 parts  of
starch gave 110-14 of sugar ;  from whence  he concluded
that a part of the water was solidified, and  thus the acid
acted only by increasing the fluidity of the  liquor.
   Sulphates.   (Sulfates.)  Of all the acids none has a
more marked tendency to combine with  salifiable bases
than sulphuric acid ; there are of course many sulphates.
This acid forms neutral sulphates, sub-sulphates, acid sul-
phates, and  many of these  can  combine  among them-
selves, forming double sulphates.
   When we examine the laws of combination of these
salts, we find, 1st, in the neutral  sulphates, the quantity
of the oxygen of the oxide is to  the quantity of the oxy-
gen of the acid, as 1  to 3, or the quantity of acid, as 1
to 5.  2d. The  sub-sulphates are not uniform in their
composition ;  sometimes they contain once  and a half  as
much oxide as  the neutral sulphates, sometimes 3 times
as  much, or  even 6 and 12 times the same quantity;
these numbers are multiples of the smallest quantity by
2, by 4, and by 8.   Berzelius  has even observed many
sub-sulphates of the same base.   3d. The acid sulphates
contain for the same quantity of base, a quantity of acid,
which is  exactly twice as great as that which the neutral
sulphates contain.   4th. In  the  double sulphates the
quantity of oxygen of one of the bases is proportionate to
the quantity of oxygen of the other base ; thus for exam-
ple in alum, (acid sulphate of alumine and potash,) the
quantity  of oxygen in  the potash is to the  quantity of
oxygen in the alumine as 1 to 3; then  the quantity  of
acid united to the alumine will be three times as  great
as  the quantity of acid united to the potash, since the
quantities of acid must be in proportion  to the quantity
of oxygen contained in the bases. 
432
S U L
  Sulphates exposed to the action of caloric, at first dia
engage their water of crystallization, and with the excep-
tion of the sulphates of Thenard's second  section,* and
the  sulphate  of magnesia,  are  all decomposed, if  the
temperature is sufficiently elevated.   Their acid is trans-
formed into two  volumes of sulphurous acid, and  one
volume of oxygen, and the oxide is reduced.   In some
cases, as when a metal has much affinity for oxygen, the
oxygen of the sulphuric  acid decomposed serves to raise
the  oxide  to  a higher degree of oxidation ; this is the
case with iron in the preparation of colcothar or the tri-
toxide of iron.
  Most combustible  non-metallic bodies can, with the
aid  of heat, decompose the  sulphate ;  carbon, producing
carbonic acid, and an oxide or rather a sulphuret; hydro-
gen, forming water  and  hydro-sulphuric acid, (sulphu-
retted hydrogen;)  sulphur, producing sulphurous  acid
and  an oxide or  sulphuret,  &c  This last combustible
substance  cannot,  however, decompose the  sulphates
which resist an elevated temperature.   Water acts vari-
ously upon these; it decomposes  many of the neutral
sulphates, changing them into an acid  sulphate and sub-
sulphate ; it dissolves many, but in a  variable quantity.
The  most soluble is that of alumine;  that  of barytes is
wholly insoluble, and it is this base which has the great-
est tendency to combine  with sulphuric acid; thus all the
sulphates disturb the water of barytes.   Many other salts
may  also be thus affected, and the  precipitate formed
should not be regarded  as the sulphate of barytes, but
when nitric  acid will not dissolve it.  Some hydracids
can,  in peculiar circumstances, and at the  ordinary tem-
perature, decompose the sulphates ; at an  elevated tem-
perature, boracic and phosphoric acids decompose them,
uniting with their base and  forming a borate  or a phos-
* See the article Metals. 
S U L
133
phutc, and  setting tree  the  sulphuric acid, which, not
being able to  exist alone, is  transformed into sulphurous
 icid and oxygen.  The great affinity of sulphuric acid
'or bases  gives  rise to many native sulphates;  those
which are insoluble are usually derived from the decom-
position of the sulphurets, by the contact of damp air,
and are often  dissolved by the waters which traverse the
galleries of mines, as they are found in springs whose
sources pass  through earth which contain  sulphates or
the materials  for forming them.   Those which are em-
ployed in the arts are usually extracted from native mine-
rals ;  some are  prepared directly by art, and many  by
double decomposition.  See each Sulphate.
   Sulphate  of Alumine.   A white, deliquescent salt,
very soluble, of an astringent taste, reddens the tincture
of litmus,  crystallizes in groups.  The solution of the
sulphate of potash  or ammonia, poured  into its concen-
i rated  solution, immediately forms a  crystalline precipi-
late of alum.   It  exists  in nature, but always with  an
iexcess of  base, and containing some water; it is known
by the  name  of  alumite or aluminatc.   It is obtained
directly by treating alumine in a jelly with sulphuric acid.
f t is also procured by burning mixtures of pyrites and ar-
gillite.  Sulphuric acid acts upon alumine and forms the
sulphate which is obtained by lixiviating and then evapo-
rating the liquor.  It is employed in preparing alum ;
■iome  of the sulphate of ammonia, or the residues of the
distillation of  nitric acid are  also added.
   Sulphate  of Alumine  and  Potash.   Acid.  See
Alum.
   Sulphate  Ammoniaco-Magnesian.   The  double
sulphate  of magnesia and ammonia.  This last  base,
poured into a solution of the sulphate of magnesia, preci-
pitates a portion of the magnesia, and takes its place,
   Sulphate  of Ammonia.   A colourless salt, of a bit-
ter and pungent taste, crystallizable in hexagonal prisms
                          37 
434
S U L
terminated by points with six sides.   If exposed to the
action of caloric, it at first loses a portion  of ammonia
passes  to the state of an acid sulphate, which at a tem-
perature a little more elevated,  decrepitates and decom-
poses, giving rise to nitrogen, water, and the volatile sul-
phite of ammonia.  This salt is very soluble, since it dis-
solves  in  two parts of  cold  water, and in  its weight  of
boiling water.  It exists in  small  quantities  in nature.
It is usually prepared by directly uniting ammonia to sul-
phuric  acid.  In  the arts, great  quantities of sulphate of
ammonia are made in the preparation of the hydro-chlo-
rate, (muriate of) ammonia.  Animal substances are for this
purpose distilled  in iron cylinders ; the product of this
distillation is conducted into vessels which  contain gyp-
sum, (sulphate of lime,) diluted with  water.   A great
quantity of oily matter collects upon the surface, which
is  removed.  The  sub-carbonate of ammonia,  which is
one of the products of this  distillation, decomposes  the
sulphate of lime, and forms  a sulphate of ammonia.   It
is by subliming a mixture of this sulphate and of chloride
of sodium, (common salt,) that the hydro-chlorate of am-
monia  is obtained.
  Sulphate of Antimony.  The oxide of antimony ha-
little affinity  for  acids; a sulphate is, however, obtained
by heating metallic antimony with 5 times its weight of
concentrated sulphuric acid.   This sulphate  is white,
heavy, and contains an  excess  of acid.  When brought
into contact with water it  changes into a very acid sul-
phate,  which remains  in  solution, and a  sub-sulphate,
which  is  precipitated.   See Tartrate  of Antimony and
Potash.
   Sulphate of  Barytes.   A  very heavy, white  salt,
hard, inodorous,  insipid, wholly insoluble in  water, and
only soluble in a  concentrated solution of sulphuric acid.
Exposed to the action of heat, it fuses at a very elevated
temperature, but does not decompose unless it is in con- 
S  I L
435
 tad with some combustible substance like charcoal, ve-
 getable substances, &c  It exists extensively in nature,
 usually accompanying  metals  in  veins, seldom  in beds.
 It is often  associated with antimony and the per-oxide  of
 manganese,  it is  then  called heavy spar (spath pesant).
 its crystals which were formerly supposed to be in rhom-
 boidal prisms, are more like rhomboidal octoedrons ;  they
 are often flat and tabular and grouped like the steps of a
 ladder.  The  sulphate of barytes is found in  a fibrous
 and even in  an earthy  state, but usually crystallized ;  in
 its system  of crystallization  it resembles the  sulphate  of
 lead.  It may  always be distinguished from that sulphate
 by sulphuretted   hydrogen,  or any alkaline  sulphuret
 which forms a black  spot upon the sulphate of lead.  The
 natural sulphate of barytes is employed to obtain barytes.
 In order  to obtain this sulphate in a state of purity, it  ma;
 be  prepared  by decomposing the  sulphate of soda  with
 the nitrate  of barytes, and washing the precipitate.
   Sulfhate of Bismuth.   White, compact,  acid ;  it  is
 decomposed  by water  into a  very acid sulphate, and a
 sub-sulphate  which is precipitated.  It is obtained,  like
 that of antimony, by heating  minutely divided bismuth
 with 5 times  hs weight of concentrated sulphuric acid.
   Sulphate of Cadmium.   Colourless, very efflorescent,
 very soluble, crystallizing  in prisms  with a rectangular
 base, which  contain much of the water of crystallization.
 Heat decomposes it, making it pass to the state of a  sub.
 sulphate.  The sulphate of cadmium is obtained  directly.
 It consists  of 100 parts  of acid, 161-12 of oxide.
  Sulphate of Cerium.   Sulphuric  acid  can  combine
 with the  protoxide and  deutoxide of cerium.   The proto-
sulphate is white, of a  sugared taste, soluble in  water,
and susceptible of being crystallized.   It is obtained di-
 rcctly.   The deuto-sulphate is in orange.coloured  acicu-
lar  crystals, some  of which are of a citron yellow.   It  is 
130
SDL
 obtained  by heating the deutoxide of cerium with weal;
 sulphuric acid, and evaporating the liquor.
   Sulphate of Cinchonine.  According to M.  Baup.
 there are two sulphates  of cinchonine, a neutral and an
 acid sulphate.
   The  first  is formed of Cinchonine,   .  .  39
                         Sulphuric acid,  .    5
                         Water,  .   .   .    2-25,
 or, 1 atom of cinchonine, 1 atom of acid,  and 2  atoms of
 water.
   The second is formed  of Cinchonine, .  .  39
                          Sulphuric acid, .  10
                          Water,    ...    9,
 or, 1 atom of cinchonine, 2 atoms of acid, and 8  atoms ot
 water.
   The  neutral sulphate  is  crystallized  in  rhomboidal
prisms ; it is soluble in  54 parts water at the  ordinary-
temperature, and in  Hi  parts of alcohol.   It is obtained
by a direct process.   The acid sulphate is colourless, un-
alterable by the air, becomes effloroscent if the tempera-
ture is  a little elevated,  crystallizes in octoedrons with
rhomboidal bases.   It is  soluble in half its weight of cold
water and in  its weight of alcohol,  but  is insoluble in
ether.   It is prepared by adding acid to the  neutral sul
phate, and evaporating the solution to a pellicle.
   Sulphate of Chromium.   Its existence only is ascer-
tained.
   Sulphate of Cobalt.  A rose-coloured salt, suscep-
 tible of crystallizing in rhomboidal prisms,  terminated b\
 dihedral summits.  It dissolves  easily in cold water;  its
solution reddens the tincture of litmus, and gives with
 ammonia  a precipitate  soluble  in an excess of alkali.
The sulphate of cobalt is obtained  by treating  with sul-
phuric acid one of the oxides of the metal.   The  proto-
 "ulphate is that which always forms, 
S U L
437
    Sulphate of  Copper.    (Sulfate de Cuivre.)   The
 deuto-sulphate alone exists.  It has a very styptic taste ;
 is soluble in 4 parts of cold water  and 2 parts boiling
 water, crystallizes  in prisms with an oblique base; its
 crystals contain a large quantity of the water of crystal-
 lization, which gives them a beautiful blue colour.   Ex-
 posed to the air, they become  slightly  efflorescent, and
 their  surface appears whitish ;  when dried entirely by
 heat,  they are white.  They melt easily in their water of
 crystallization, and of course  cannot become white till
 having been thus fused.   When heated  in  a  crucible
 with charcoal, it  decomposes, and the metal is reduced.
 Its solution is precipitated by potash and soda ;  ammonia
 forms  with it a greenish blue  precipitate,  which dissolves
 n an excess of alkali and forms  a liquid of a beautiful
 blue, which the ancients called celestial blue.   Sulphu-
 retted hydrogen  forms with it a dark brown precipitate.
 The ferro-cyanide  of potassium precipitates it crimson,
 and the simple cyanide  yellow.  Iron  and phosphorus
 decompose it, and  become covered with a coat of metallic
 copper.   The water of barytes precipitates it a bluish
 white, the precipitate is formed of the sulphate of barytes
 and the hydrated oxide of copper.
   The sulphate of copper is seldom found crystallized in
 nature ;  this sulphate  is common  in  the waters  of  the
 galleries of mines which contain pyrites of copper ; it is
 sometimes found  in such quantities as to be used for  the
 extraction of copper ;  for this purpose the waters are col-
 lected  and evaporated.   This is  called the  copper of ce-
 mentation.   Large  quantities  of copper  are obtained- by
 roasting  ores which contain  sulphuret of copper;  the
 most common method, and that by which this metal is ob-
 tained  in its purest state, is byr extracting it  from the sul-
 phuret of copper  by roasting.   This salt  is of use in
medicine and in the  arts.   It consists of 100 of acid and
99-126 of base. 
138
S U L
  Sulphate of  Copper Ammoniacal.  This salt is of
a beautiful blue colour, it  is distinguished  from the sul-
phate of copper, 1st, by its ammoniacal odour ; 2d, by its
property of greening the  infusion of violets ; 3d, by the
green precipitate which it gives with solution of the deut-
oxide of arsenic ; this  precipitate  which is the arsenite
of copper is very  abundant, and  appears  immediately.
while the deutoxide of arsenic with the sulphate  of cop-
per, does not furnish an evident precipitate until 20 or 25
minutes have elapsed.   (Orfila.)
  Sulphate of Gold. {Sulfate d'Or.) Pelletier observed
that the deutoxide of gold might be dissolved in concern
trated sulphuric  acid ; but  as these  two bodies have little
affinity, if water is  added to the  liquid, sufficient heat i
produced to reduce the gold, which  precipitates in ablacl
powder.
  Sulphate of Glucina.  A  sugared salt which attracts
humidity from  the air,  is very soluble in water,  crystal
lizes, but with difficulty, in acicular  prisms.  It isprepareti
by a direct process.
   Sulphate of Iron.  (Sulfate de Fer.) Sulphuric acid
combines with three oxides of iron ; but according to Ber-
zelius, there exist but the proto and trito-sul phates.  Ik-
regards the deuto-sulphate as  a  compound of the  two
others.   It is certain that by pouring an  alkali into it.'
solution, it  forms a  precipitate of tritoxide.  If this pre-
cipitate is separated, and another precipitate is made with
the same substance as before, the precipitate will then he
almost wholly formed of the protoxide.  Thus Berzelius
considers the deutoxide of iron, as  a ferrate of iron, or a
compound of the protoxide and the tritoxide of the samp
metal.
   The proto-sulphate is usually in the form of rhomboidai
transparent crystals, of a beautiful  green  colour, and ;.
very styptic taste.   Exposed  to the air, it becomes efflo-
 rescent, and its surface  covered  with ochre-like spots. 
SUL
439
which are the sub-trito-sulphate.  It is soluble in 2 parts of
cold water.  Its solution  is green, and soon decomposes ;
when left in the air it becomes red, giving a yellow precipi-
tate, of the  sub-trito-sulphate.  Its colour is owing to the
trito-sulphate which it contains, and which is  formed by
the absorption of oxygen  from the air.   Tiie proto-sul-
phate of iron owes its colour to its water of crystalliza-
tion, of which it contains TYo of its weight ; for if de-
prived  of this by dissication, it becomes entirely white.
Owing  to the great quantity of  water ot crystallization.
by heating this sulphate suitably, a certain quantity of very
concentrated sulphuric  acid may be obtained, which is
known  by the name of " Sulfurique glacial  de Nordhau-
<en."   The  residuum is the tritoxide of iron.
   The  solution.of the proto-sulphate of iron, can absorb
a certain quantity of the deutoxide of nitrogen, which is
disengaged by heat; this same solution is not precipitated
by sulphuretted  hydrogen,  but  by the ferro-cyanide of
potassium, forming a white precipitate, which immediately
becomes blue by contact with the air. Chlorine produces
the  same  effect; and the  simple cyanide of potassium
causes an orange  precipitate.   This  sulphate is seldom
 found in nature in a solid state, but as the sulphuret of
this metal  is very abundant, and is easily changed by
contact with the air to  a  proto-sulphate, this  salt on ac-
 count, of its fo!ability is often found in solution in waters
  lowing in  mineral regions.  As  this sulphate brings  a
 low price, it is seldom obtained by the expensive method
 of evaporating these waters, but generally by exposing
 to the  air the pyrites or the sulphuret of iron, which de-
 composes gradually.  This salt is used in dyeing  ; it con-
 sists of 100 of acid and 87-836 of base.
   The deuto-sulphate is prepared by treating the deutoxide
 of iron with weak sulphuric acid, at 'he same  time avoid-
 ing access of air.   It is soluble in water ; the t ulution  al
  liv-t easiiv absorbs oxygen from the  air, and passes to the 
440
SUL
 state of a trito-sulphate.   It is  not precipitated b) sul-
 phuretted hydrogen, but the ferro-cyanate of potassium
 produces with it a clear blue precipitate, and the simple
 cyanide an abundant bluish green precipitate.
   The trito-sulphate, is  of an orange colour, styptic like
 the preceding, reddens the tincture of litmus, is soluble in
 water, and has never been made to crystallize.  An excess
 of sulphuric acid increases  its solubility, and renders ii
 almost white ;  an excess of oxide  renders it yellow.   II
 when evaporated to  dryness, an attempt is made to redis-
 solve it in water, it changes to an  insoluble sub-sulphate,
 and a soluble acid sulphate, which remains in the liquor.
 Sulphuretted hydrogen forms a yellow precipitate of sul-
 phur in the solution  of  the  trito-sulphate of iron.   The
 ferro-cyanate of potassium produces with it an abundant.
 deep blue precipitate, while  the simple cyanide scarcely
 forms any. This salt is obtained by treating the hydrated
 tritoxide of iron with sulphuric acid.
   Sulphate of Lead.   (Sulfate  de Plomb.)   A  white
 salt,  very heavy, insipid, insoluble, volatile in the air,  at
 a  high  temperature. It is little soluble in an excess  of
 acid ; but dissolves readily in hydro-chloric  acid.   When
 heated with charcoal, carbonic and sulphurous acids are
 disengaged, and a sub-sulphuret is formed.  The sulphate
 of lead exists in nature ;  it is found in crystals, of which
the prevailing form is the octoedron more or less trun-
 cated ; these  crystals are sometimes transparent, isolated,
 but more commonly collected in  a crystalline mass  re-
 sembling the sulphate of barytes; from the  sulphate  it
 may  be distinguished by its  forming a black spot when
 brought  in contact  with sulphuretted hydrogen, and in
 giving with the  blow-pipe a  metallic globule.   It is ob-
 tained by pouring a solution  of the sulphate of soda into
 a solution of the acetate of lead.   It consists  of 100 of
 acid and 278-89 of the protoxide of lead. 
S  U L
111
   Silpiiate of Lime.  (Sulfate de  Chaux.)  Gypsum.
 Plaster of Paris.  Without colour when pure, soluble in
 300 parts of cold water,  of course  more soluble  than
 lime.   Exposed to the action of fire,  it loses  its water of
 crystallization, and fuses in a  white enamel. It has much
 affinity for water, for if after losing by heat its water of
 crystallization, it is exposed to  the  air, it absorbs that of
 the atmosphere  without changing its state.
   The sulphate of lime, or gypsum (gypse)  is abundant
 in nature ;  when it does not. contain water,  it is called
 anhydrous.   It is usually found crystallized, fibrous, com-
 pact, &c.   Its crystals are upright quadrangular prisms.
 they have a peculiar tendency to arrange  themselves in
 groups, and round their angles.  In the fibrous varieties,
it has been remarked that the fibres are  usually perpen-
 dicular to the side of the veins which contain them.  The
 Compact sulphate of lime is found in  great quartities in
the environs of Paris ; hence us  name.  It commonly
offers a pseudo-regular  structure, and seems like   the
basalts,  to divide into large prisms.  This last variety is
chiefly used as a plaster stone.  The white crystallized
sulphate of lime is usually pure enough  for all practical
purposes, but a still purer sulphate may be obtained by the
 lirect combination  of lime, and sulphuric acid.
  Sulphate of Lithium.   White, very sapid, suscepti-
ble of crystallization in irregular masses, very soluble in
water, and unalterable by the air.  h fuses with difficulty.
When treated with sulphuric acid it  forms an acid  sul-
phate less soluble in water  than the neutral sulphate, bu1
which fuses more easily.   It can form with the acid sul-
phate of alumine, a double  salt analogous to  alum,  and
which like that crystallizes in octoedrons, sometimes in
in  dodecahedrons.  The sulphate of lithium is prepared
by a direct process.  It can also be obtained by peculiar
processes  from the  ores  which contain  th^ oxide of 
142                   S I  L
lithium.  The neutral sulphate of lithium is composed of
 48-41 of acid to 31-59 of the base.
  Sulphate of Magnesia.  In taste it is similar to thai
of the sulphate of soda, though less bitter.   Ii was for-
merly called sul  catharticus amarus,  or  bitter cathartic
salt.  It is now known by the name of Epsom salt,  being
furnished in considerable quantity by the mineral waters
in that place ; it is someiimes called Sedlitz  salt, from a
village in Bohemia  which  also contains  mineral waters
strongly impregnated with it.   It is white, very  soluble
in water,  crystallizes  in  \-sided prisms, terminated by
points with 4 faces.  It effloresces  in the air, fuses  in its
water of crystallization when exposed to heat, but  does
not  experience  the  igneous fusion.   The neutral car-
bonates of potash and  soda do not precipitate this sul-
f)hate, but if the mixture is heated,  a  portion of carbonic
acid is  disengaged,  and a precipitate is formed.  The
sulphate of magnesia  is in commerce often imitated by
the sulphate of soda whose crystallization  has been dis-
turbed : the appearance and even the taste may deceive.
hut the mistake  can be discovered by pouring  into the
solution either potash or soda, which precipitates  the sul-
phate of magnesia, but does not affect the sulphate  of soda.
  The sulphate of magnesia exists in  the waters of  manv
springs, in so great quantities as to give them a very  bitter
faste and  strong medicinal properties.  It  may be  ob-
tained by evaporating, purifying,  and crystallizing  these
 vaters.   According to  Gay,Lussac, 17-799 parts of the
sulphate of magnesia contain,
                Acid,   .  .  5-790,
                Magnesia,  .  2-855,
                Water, .  .  9-154.
This salt is of important use in medicine.
  Sulphate of Manganese.   Sulphuric acid forms two
salts with  the oxides of manganese.  The proto-sulphate
!« white, of an astringent and bitter taste, susceptible of 
S I  L
44^!
 forming rhomboidal crystals, very soluble, decomposable
 by heat.  It is obtained by heating in a crucible a paste
 of the peroxide  of manganese and sulphuric acid; from
 this  mixture is obtained the  sub-proto-sulphate and the
 neutral sulphate.   They are separated by water.   The
 per-sulphate always exists with excess of acid ;  it is red.
 decomposable by water,  which unites with its sulphuric
 acid.   It is obtained by treating the per-oxide of man-
 ganese with concentrated sulphuric acid.  The deuto-
 sulphate does not exist; sulphuric acid  changes the deut-
 oxide  of  manganese into  a  protoxide  which  dissolves.
 and  the deutoxide which is precipitated.
   Sulphate of Mercury.   The  proto-sulphate is white.
 pulverulent, insipid, insoluble in water, soluble in excess
 of acid.   It is obtained by decomposing the proto-nitrate
 >f mercury with the sulphate of soda.  The deuto-sulphat<
 can  also be  obtained  by double  decomposition, by em-
 ploying the  deuto-nitrate of mercury.  It may also be
 prepared  by treating in a retort mercury and  sulphuric
 acid ;  one part of the acid is  decomposed, oxidates the
 metal, and the  remainder is  disengaged  in the state of
 sulphurous acid; the other unites to the  oxide formed,
 producing a white mass, which  is the  deuto-sulphate of
 mercury.   If this mass is washed with boiling water, it
 changes to a colourless acid  deuto-sulphate,  which re-
 mains  in solution, and  a sub-deuto-sulphate which pre-
 cipitates in a yellow powder.   This powder, washed and
 dried,  was formerly known in pharmacy by the name of
 lurbith mineral.   The acid sulphate may be employed in
 the preparation of the deuto-chloride of mercuiy.
   Sulphate of Molybdenum.   Its existence only i>
 known.
   Sulphate of Morphine.   A salt  having a very bitter
 laste, soluble in  water, and susceptible of crystallizing in
silkv radiated needles.  It can  unite  to  an  additional 
444
SUL
quantity  ; f acid and  forms an acid sulphate.   It is ob-
tained by a direct process.
   Sulphate of Nickel.   A  beautiful green  salt,  of a
sugared  and astringent taste.   It effloresces in the air.
dissolves  in  three  parts  of  cold water, crystallizes in
rhomboidal transparent prisms, which  contain 45 for 100
of the water of crystallization,  easily  passes into the
aqueous fusion.   It is  obtained directly, and consists of
47-8 of acid and 52-0 of base.
   Sulphate of Platina.  Of an orange yellow colour,
a styptic taste, reddens litmus, is very soluble in water,
crystallizes with difficulty.   Like all  salts whose metals
have  little affinity for oxygen, it easily  decomposes by
heat and the  metal is set free.   The sulphate  of platina
can form double salts with the sulphates  of potash,  soda,
and ammonia.  It is  obtained by treating the sulphuret
of platina with nitrous acid.
   Sulphate of Potash.   A white salt of a bitter  taste,
which crytallizes in 6-sided prisms, terminated  by  pyra-
mids with 6 faces.  It is soluble in 12  or 15 parts of cold
water  and in 5 parts  of boiling  water.   It  contains  no
water of crystallization, but a little water of interposition,
which gives  it the property of  decrepitating when ex-
posed to the action  of heat;  it is unalterable by the air.
This salt is employed in medicine, but not so much now
as formerly, when it was known as the arcanum duplica-
tetn, sal polychrest, vitriolated  tartar, &c ;  its composition
long remained a  secret.  Tarquinius  obtained  it by de-
composing the sulphate of iron with the sub-carbonate of
potash.  It  is prepared directly by uniting  potash  with
sulphuric  acid ; but is more frequently obtained from the
residues in the manufacture of nitric acid, these are en-
tirely composed of the acid sulphate of potash; the ex-
cess of acid  is saturated, not with potash which is more
extensive than the sulphate, but with  lime ;  water  being
added, it  is  filtered and evaporated, and crystals of the 
SUL
445
-ulphate  of potash are obtained.   This salt  consists of
acid 100 and  base 117-996.  It is easy to distinguish a
solution of the sulphate of potash from a solution of the
sulphate  of soda, by testing  them with tartaric acid or
the chloride of platina;  the solution of the sulphate of
soda will not be affected by either of these substances,
while that of the sulphate of potash will give with tartaric
acid a white, and with the chloride of platina a yellow
precipitate.
   Sulphate of Potash  (Bi.).   This salt was  disco-
vered by Ronelle ; it crystallizes  in needles,  and some-
l imes in 6-sided prisms ; its taste is acrid ;  it reddens the
vegetable blues ;  is soluble in 2 parts of water at 60°, and
in much less of boiling water ; it melts  readily, becoming
opaquely^ white on cooling.   It is"  usually obtained in the
process for nitric acid,  and is not used except to form
the sulphate.  It contains two proportions of sulphuric
acid, and one of potash.
   Sulphate of Quinine.  Avery bitter, white salt, sus-
ieptible  of crystallizing  in fine pearly needles, which
collect in light masses.  This salt becomes luminous at
the temperature  of boiling water.  It is little soluble in
water, but becomes very much so, by the addition of a
quantity  of sulphuric acid ;  this forms  an  acid sulphate.
The  science  of medicine is indebted to Pelletier and
Caventon,  for the discovery of this important and valuable
substance,  one  of the  most precious of the  Materia
Medico.   The sulphate of quinine exists united to a small
quantity  of kinic acid in the yellow quinquina (Cinchona
officinalis of Linnaeus).  It is obtained by boiling  twice
for a quarter of an hour, the powdered quinquina bark in
a  sufficient quantity of water ; 1 ounce of sulphuric acid
to a pint of water is then added. These decoctions which
contain the sulphate of quinine, are united, saturated by
lime, and  filtered; the deposite on the filter being well
dried, is then heated with alcohol to  97°; the liquor is
                          38 
146
SUL
left to cool and deposite, then decanted, and  the residue
treated with a new quantity of alcohol; this  operation in
again repeated, and continued until the alcohol shows by
being destitute of a bitter taste, that it no longer holds any
of the quinine in solution;  all  these  liquors  are then
united and distilled; in the distilling vessel will remain a
thick blackish substance ;  this is quinine.  To form the
sulphate,  the quinine thus obtained, must be boiled  in
water acidulated by sulphuric acid ;  this dissolves it en-
tirely ; the boiling liquor is then  filtered, and on cooling,
deposites a coloured sulphate of quinine; this is purified by
new crystallizations, and by  being treated with  animal
charcoal.
  When  little crystalline scales  are  observed  in  the
boiling liquor, it  should be  filtered, as it  will then on
cooling, form a solid  mass.   The  filters which are used,
should first be washed in acidulated water.  The sulphate
of quinine should be dried with  a moderate heat, and
between sheets of paper, that it  may not be  coloured by
the air.*
  Sulphate of Silver.   (Sulfate d'Argent.)  A white
salt of a metallic taste, little soluble in water, but becomes
more so by an excess of acid.  Exposed to the action of
fire, it first melts, then decomposes.   Like  most of the
compounds of silver, it is very soluble in  ammonia, and
forms a white  precipitate with  muriadc acid.  It is ob-
tained by  decomposing a solution of the sulphate of soda,
by a solution  of the nitrate of silver.   It can also be ob-
tained by  a direct process.
  Sulphate  of Soda.   (Sulfate de  Soude.)   Is also
called Glauber's salts, in honour of the chemist by whom
it was discovered ;  the discovery was made in examining
the residues in the  preparation of muriatic acid.   It is a

 * The authors add in a  note that  while their work was in press, they had
learned that  a pharmacian at Toulouse, had discovered the quinjne in all the
species of Cinchona, it being in all cases found combined with kinic acid. 
SUL
447
 colourless bitter salt, susceptible of forming very large
 crystals, which are six-sided prisms, terminated  by sum-
 mits with two faces, and containing f5^ of the water of
 crystallization. It effloresces very soon in the air.  Gay.
 Lussac made some curious experiments upon its solubility
 in water; the result of them is, that at the temperature of
 92°, water  dissolves its greatest proportion of the  salt,
 and that with either more or less heat, it dissolves less.
 Water at 92° dissolves half its weight, and at 32° but
 one-twentieth of its weight, and at 212°  about the same
 as at 32°.   It often happens that its solution, when stand-
 ing entirely undisturbed, will not crystallize, though upon
 being  slightly  agitated,  crystallization  will soon  take
 place.  It is prepared in great quantities by decomposing
 the chloride  of sodium (common salt) by sulphuric acid.
The sulphate  of  sodium  consists of  100  of acid  and
78-187 of soda.  This salt  is very useful in medicine  ;
 it is used in the arts for the preparation of artificial soda,
 and for purifying the pyro-ligneous acid
  Sulphate of Strontian.   {Sulfate de Strontiane.)  A
 white, insipid, and inodorous salt, scarcely soluble in
 water, yet more soluble  than the  sulphate of barytes,
 since  it dissolves in 4000 parts  of water ; it resembles the
 sulphate of  barytes in all its properties ; it has, like that,
 a density of 4.  It is found in nature in  different situa-
 tions,  sometimes   in  regular crystals  of  rhomboidal
 prisms, like those of the sulphate of barytes, except that
 the angles  are different; the faces of the point which
 terminates the crystals of strontian, form an obtuse angle
 with the axis of the  prism, while the faces which termi-
 nate the crystals  of the sulphate of barytes, present an
 acute ar.gle.   The sulphate of strontian is also formed in
 little fibrous masses,  usually of a clear blue, from which
 it has  received the name of celestine ; it is often found in
 compact masses, containing a little carbonate of lime.
 ft is not, like "the sulphate of barytes, found in veins, but 
148
SUL
almost always in beds.  The sulphate of  strontian 1^
used for obtaining strontian ; this sulphate  may be pro-
cured artificially, by pouring a solution of  the sulphate of
soda into the solution of a salt of strontian.
   Sulphate of Tellurium.   (Sulfate de  Tellure.)  Co-
lourless, soluble in water, is easily decomposed by calo-
ric  It is obtained by a direct process.
   Sulphate of Tin.   (Sulfate d'Etain.)   Tin has little
tendency to form combinations with acids ;  this is perhaps
owing  to the  density of its oxide;  yet by treating  this
metal with concentrated sulphuric acid, a sulphate is ob-
tained which presents nearly the same physical charac-
ters  as the sulphate of barytes, and  which like that  dis-
solves in very small  quantities in sulphuric acid ;  but if
instead  of proceeding in the manner  above described.
concentrated sulphuric  acid is poured  into a solution of
the proto-chloride of tin, hydro-chloric acid is disengaged,
and  a flaky precipitate formed, which can dissolve in
water and crystallize in acicular prisms by a careful eva-
poration.  'If this new sulphate, by aid of heat, is treated
with a new quantity of sulphuric acid, it  passes  to  the
state of  an acid deuto-sulphate, which remains  in  the
liquor without  crystallizing.
   Sulphate of Titanium.   (Sulfate de  Titane.)   Co-
lourless,  uncrystallizable, always contains  a small quan-
tity of the sulphate of potash, provided that the oxide of
titanium  is employed  in  its preparation, which is itself
prepared through the agency of potash.
   Sulphate of  Thorina.   (Sulfate  de  Thorine.)   A
white salt, of  an astringent taste, and  soluble in water.
On evaporating its solution, crystals without colour  and
unalterable by the air are obtained; but if  left to itself,
the solution in time  deposites an insoluble sub-sulphate,
and  the liquor contains an acid sulphate.
   Sulphate of  Uranium.   The proto-sulphate  exists,
but  is scarcelv known.   The deuto-sulphate  is yellow. 
SUL
449
 acid, very soluble in water; it crystallizes, but with diffi-
 culty, in short prisms, containing 12  parts in 100 of the
 water of crystallization.   It is obtained by heating the
 deutoxide of uranium with diluted sulphuric acid.
    Sulphate  of Yttria.   A  white salt, of a  sugared
 taste, soluble in 40  parts of cold water, susceptible of
 crystallizing ; it is obtained by treating yttria with diluted
 sulphuric acid.
    Sulphate  of Zinc.  A white salt,  of a sharp  and
 styptic taste; it is obtained in  granular masses, resem-
 bling sugar, but crystallizing in four-sided prisms, termi-
 nated by points with four faces;  it effloresces in the  air,
 fuses easily  in  its water of crystallization, of which it
 contains 36 parts in 100.   It is o ten covered with ochre-
 like spots, which indicate that it is rendered  impure by
 the presence of iron.   It  is soluble in 3 parts  of cold
 water, and in a less  quantity of boiling water; the solu-
 tion reddens  the tincture of litmus,  and a  precipitate is
 formed by alkalies  which  redissolve the precipitate if
 added in  excess.   This precipitate  is  greenish white
 when the  common  sulphate of zinc is used, but perfectly
 white when pure  sulphate  of zinc  is  employed.  The
 ferro-cyanate  of potassium  produces a  blue precipitate
 with the sulphate of zinc of commerce ; this precipitate
 is white when the  sulphate is pure.   The alkaline hydro-
 sulphurets form with it a blackish deposite ;  this is whitish
 when the salt is pure.  The chromate of potash forms an
 orange precipitate ; an infusion of nutgalls forms  no pre-
 cipitate, unless other sulphates are in solution.  The sul-
 phate of zinc is  employed  in  medicines; it is obtained
 pure by treating zinc with diluted sulphuric acid.  That
 which is  used in commerce is obtained  by roasting the
 sulphuret  of zinc;  but as this sulphuret  always contains
some foreign sulphurets, this  sulphate is not pure.  It
can be purified  by boiling it with  the oxide of zinc,
 which decomposes  the sulphates of iron and copper which
                         38* 
450
SUL
are the most common substances by which the sulphate
of zinc is adulterated.   This salt consists of 100 of acid,
and 100-655 of base.
  Sulphate of Zirconium.  White, insipid, pulverulent,
very soluble in water; it is obtained by double decom-
position.
  Sulphates  (Hypo.)  (Hypo from the Greek upo, less,
the hypo-sulphates containing less oxygen  than  the sul-
phates.)   The hypo-sulphates  when  exposed  to the
action of heat are changed  into neutral sulphates and
sulphurous acid.   These sulphates do not readily absorb
oxygen from the air;  they  are all more or less soluble in
water.   Sulphuric acid  poured into these solutions takes
the place of the hypo-sulphuric acid, and the latter re-
mains in the  liquor ; but if this acid is added to a hypo-
sulphate  without any water, the acid is decomposed, and
sulphurous acid and a sulphate  are  formed.  The hypo-
sulphates are  prepared  directly, except that  of barytes
and some others.  In these salts the  quantity of oxygen
of the oxide is to the quantity of the acid as  1 to  9.
   Sulphites.  (Sulfites.)  They resemble the sulphates
in their properties ; but as  sulphuric acid  has great affi-
nity for bases, and as combinations formed with this acid
are very  permanent, the sulphites easily absorb oxygen,
and pass to the state of  sulphates ; this takes place at the
ordinary temperature, when  they are exposed to contact
with the  air, and still more readily occurs when  they are
treated with nitric acid; this acid yields to the  sulphites
a portion of oxygen, changing them  to  sulphates, and
becoming itself a deutoxide of  nitrogen ; thus by heating
a sulphite whose base has much affinity for sulphuric acid,
as magnesia and soda,  the sulphite will leave a portion of
sulphur,  and pass to the state of a sulphate with excess of
base;  if it  is a sulphite with  excess of  acid, there will
also be a disengagement of sulphurous acid; but if the
oxide has little affinity for the acid, the latter will escape, 
SUL
451
and the metal will be reduced.   Many acids decompose
the sulphites at the ordinary temperature, and disengage
sulphurous acid ; all the sulphites, except those of potash,
soda, and ammonia, are insoluble in water.
   The insoluble sulphites are obtained by double decom-
position ; those which are soluble are obtained by passing
a current of sulphurous acid over a  portion of potash,
soda, or ammonia.   This sulphurous acid is prepared by
heating in a  matrass  weak  sulphuric  acid  with  small
pieces of wood ; sawdust should not be used, because that
determines  immediately the  formation of too great a
quantity of sulphurous  acid, which  may occasion the
bursting of the matrass.  In the sulphites, the quantity of
oxygen of the  oxide  is  to the quantity of the oxygen  of
the acid as  1 to 2, and to  the quantity of acid as 1  to
1-48.  In the neutral sulphates, the quantity of oxygen
of the oxide is to the quantity.of oxygen of the acid as 1
to 3.   Thus  a sulphite can by absorbing oxygen pass to
the state of a sulphate without changing its state of satu-
ration.
   Sulphite of Ammonia.   (Sulfite d'Ammoniaque.)   A
colourless salt, of a fresh and  pungent  taste, soluble in its
weight of cold water, and  in  a less, quantity of boiling
water.  Its solution easily absorbs oxygen from the air,
and  becomes a sulphate; if the solution,  without  being
thus exposed to the air, is submitted to evaporation, crys-
tals of the sulphite are obtained ; these are 6-sided prisms
terminated  by points with 6  faces, often truncated.   A
very volatile acid sulphite  is obtained  by decomposing
with heat the common sulphite.
   Sulphite of Lime.   (Sulfite de Chaux.)  White, pul-
verulent, insoluble,  absorbs oxygen from the  air when
boiled with water and  occasionally agitated .during the
boiling.  It is obtained  by double decomposition.
   Sulphite of Potash.  (Sulfite de Potasse.)  White,
susceptible of crystallizing  in acicular prisms which de* 
452                    SUL
 crepitate when  exposed to the action of caloric.   It i.s
very soluble in water, dissolving  in its  weight of  cold
water.  It is prepared by a direct process.
  Sulphite of Soda.   (Sulfite de Soude.)  Less soluble
than that of potash, crystallizes more  easily.   It is obtain-
ed,  like the sulphite of potash, by a direct process.
  Sulphites (Hypo.)   Sulphuretted  sulphites.   What
has been discovered with respect to them is chiefly owing
to the labours of M.  Herschell.  They are  salts resem-
bling the sulphites ; they however decompose less easily;
exposed to  the action of fire, they are  all  destroyed.
though at different temperatures ; those which have much
affinity for oxygen  absorb this gas, disengaging a part of
their sulphur, and  becoming  sulphates; if  the sulphate
formed is decomposable by heat, a sulphuret or even an
oxide  may be formed; but when the metal has little  affi-
nity for oxygen, the hypo-sulphurous  acid  decomposes
into a sulphurous acid which  is disengaged, and sulphur
which often forms  a  sulphuret with the metal.  Many of
the  hypo-sulphites dissolve in water, and  can be crystal-
lized by a careful  evaporation.  Most acids decompose
the  solutions of these  sulphites, disengaging sulphurous
acid, precipitating sulphur, and forming a new salt, which,
if it is insoluble, precipitates with the sulphur, or if solu-
ble, remains in the water.  The hypo-sulphites combine
easily  among themselves, and form  double  salts.  It
appears that hypo-sulphuric acid can  combine in different
proportions with salifiable bases ; for there are  hypo-sul-
phites in which the quantity of oxygen of the oxide is to
the  quantity of oxygen of the acid as  1 to 2, and others in
which the quantity of oxygen of the  oxide is to the quan-
tity of oxygen of the acid as 1 to 3, in some even as  1 to
1.  Many hypo-sulphites are  obtained by boiling the  sul-
phites with sulphur pulverized ; they may be obtained by-
double decomposition, or by passing a current of sulphur-
ous acid over an alkaline hydro-sulphuret. 
SUL
453
    Sulphites Sulphuretted.   See Sulphites (Hypo.)
    Sulpho-Cyanides.   See Cyano.Sulphurets.
    Sulphur.  (From the Greek sul and pur, fire, so called
 from  its great combustibility.   In French, Soufre.)   It
 is an  undecomposable body, solid, of a fine yellow colour,
 insipid, inodorous, very  brittle;  its  specific gravity is
 7-99.   It gives off an odour by rubbing, and may in this
 manner be heated sufficiently to break with a crackling
 noise; by rubbing also, like amber, it discovers the  re-
 sinous electricity.  It  is a bad conductor of the electric
 fluid.   It fuses at 218°.   If the liquid part is turned off
 when  the outer crust is solidified, acicular  crystals are
 obtained.   The native crystals  are octoedral with rhonu
 boidal bases,  often translucid,  and which then exhibit
 double refraction like the rhomboidal crystals of carbonate
 of lime.
   Sulphur volatilizes at a high temperature, and sublimes
 in  the receiver;  if heated in the air or in oxygen gas,
 it forms sulphurous  acid,  exhibiting  in  the  oxygen a
 white  flame, and  in  atmospheric air  a blue   flame.  It
 combines also with oxygen to produce sulphuric, hypo-
 sulphuric,  and  hypo-sulphurous  acids.  It  also forms
 combinations with most simple metallic and non-metallic
 bodies.  Water has no action upon it, but it is soluble in
 the essential and fixed oils, the  per-carburet of sulphur,
 and crystallizes by  evaporation.  In  contact with dif-
 ferent  chemical  compounds, and by the aid of heat, it
 acts like  a deoxygenating substance, producing  sul-
 phurous acid.   Sulphur  is very  abundant  in  nature.
 Humboldt found large masses in the Cordilleras.  It is
 found  very abundant in volcanic countries, disseminated
 in earthy substances, sometimes in beautiful  translucid
 crystals, at others it  forms stalactites, or  concretions, in
stagnant waters.   It enters into combinations with hydro.
gen under the names of sulphurets and sulphates ; it exists
in  some vegetable  and animal substances; as the cruci- 
4&                   SUL
form plants and  in  eggs.   Sulphur being volatile  ami
usually combined with  substances which are not  so, its
extraction is very easy.  It is obtained  from the  earths
by placing the ore in large covered crucibles, which are
heated in a galley-furnace.  The sulphur which is ob-
tained is purified by a new distillation;  this is performed
in a large caldron of cast iron, which is connected with a
lateral chamber.  If the operation is suspended at the end
of eight or ten hours, the sulphur has not time to form a
solid mass, and the flour, or  flowers, of  sulphur are ob-
tained ;  if the operation is continued, the sulphur collects
in masses upon the floor of the chamber ; it is then, in a
melted state, drawn  out  by  means  of  a stop-cock, and
passes  into conical wooden moulds; this is called brim-
stone, which is always  seen in small  rolls.   Sulphur  may
be extracted  from the  sulphuret of iron by heating it
sufficiently in cast iron vessels.   Sulphur has numerous
uses : it  is employed in medicine ;  very great quantities
are consumed in the  preparation of sulphuric  acid and
gunpowder ; it is burned for the preparation of sulphurous
acid, for the bleaching  of silk, straw, and Leghorn hats,
and for sulphurous vapour-baths, &c
  Sulphur Golden of Antimony.  (Soufre dore d'Anti.
moine.)   See Sulphuret of Antimony.
  Sulphur Hydrogenated. (Soufre Hydrogene.)  See
Hydruret of Sulphur.
  Sulphur Oxymuriated.   See Chloride of Sulphur.
  Sulphurets.   (Sulfures.)   Combinations of sulphur
with combustible bodies.  Of all combinations which com-
bustible bodies can form  among themselves, there are in
nature  none which  perform  a more important part than
the sulphurets.   A great number exist  already formed,
and chemistry can create still more.  It appears certain
that a metal, for example, can combine  with  sulphur in
as many proportions as it can combine with oxygen;  and
that there exists  even  as simple relations  between the 
SUL
455
 different quantities of  sulphur which it can contain, as
 between the quantities of sulphur and  the quantities of
 oxygen which it would contain in the state of an oxide.
 There exist then the proto, deuto, and trito sulphurets as
 there are protoxides, deutoxides, and tritoxides.  Berze.
 lius, taking for an example the numerous combinations of
 potassium and sulphur in definite proportions, supposed
 there might be as great a number of sulphurets of other
 substances; but  as no other substance has so great an
 affinity for  sulphur as  potassium, it happens that either
 these  sulphurets do  not  form, or if they do, are imme-
 diately destroyed.  Thus Berzelius  obtained a sulphuret
 of the colour of  blood,  composed of  1 atom of lead and
 10 atoms of sulphur ;  but this combination was soon de.
 stroyed, and changed  spontaneously into  an ordinary
 sulphuret and sulphur.
   Not only are the sulphurets always formed in definite
 proportions, but those proportions are the same as those
 which exist  in the sulphates; thus, if by any means a
 quantity of oxygen sufficient to acidify the sulphur to its
 maximum, and to  carry the  metal to  the state of a pro.
 toxide, is added  a proto-sulphuret,  the result will be a
 neutral sulphate.  The sulphurets  can  also  combine
 among themselves, and form compounds in definite  pro-
 portions ; so that the  quantity of sulphur of one is to the
 quantity of the sulphur of the other,  in  a given propor-
 tion ; the same as in a salt, where the quantity of oxygen
 of tho oxide  is to the  quantity of oxygen of the acid in a
 proportion uniform in all salts of the same kind, and  in
 the same state of saturation.   These combinations of the
 sulphurets are frequent in nature ;  when they exist in
 favourable circumstances, they often absorb oxyrgen, and
 become sulphates.
  The physical properties of the sulphuret are too various
to be generalized  in description.   We shall in this article
consider only the manner in  which they are affected by 
i56                   S V  L
  the action of caloric  It might perhaps be foreseen \\ hat
  would take place in this case, by considering the affinity
  of the metal for oxygen, and also by noticing the fact that
  if the metal has much affinity for oxygen, it has equally
  as great for sulphur by examining if the sulphur is at its
  minimum or maximum of sulphuration, and knowing the
  degree of heat to which the sulphurets ought to  be sub-
 mitted.   If the operation is performed in a vacuum, some
 such as  those of mercury and arsenic volatilize ; others,
 as those of potassium and sodium, Experience no altera-
 tion ; those which are in the state of per-sulphurets, yield
 a portion of their sulphur, and pass to  the state of proto-
 sulphurets, which  an elevated temperature will not de-
 compose if the metal have much affinity for oxygen, as
 iron ; but will  almost wholly decompose if the  metal is
 one of those which, like gold, platina, &c have little ten-
 dency to form or maintain combinations.
   If the  sulphurets are submitted to the action of heat in
 the  air,  those whose metals  have much affinity for
 oxygen,  absorb this gas, and form sulphates.  This is the
 case with most  of the sulphurets ; but each requires a dif-
 ferent temperature.   Thus the  alkaline  sulphurets  can
 become sulphates  only at a high temperature, because
 these sulphates are undecomposable by heat; the case is
 very  different  with  the  other sulphurets which  cannot
 pass through this transformation, but at a degree of heat
 inferior to that  which is necessary to produce a decom-
 position of the sulphates which they form.   If the proto-
 sulphuret of iron is slowly and moderately heated,  the
 iron oxidizes, the sulphur passes to the  state of sulphuric-
 acid,  and  the  proto-suiphate  of iron is  formed  by the
 union of the new oxide of iron and the sulphuric acid.
 But if the same sulphuret is exposed to a high tempera-
ture, the  sulphur not forming sulphuric acid, which is de-
composed at a  high temperature, is disengaged  in  the 
SUL                   457
 state of sulphurous  acid, and  the metal remains in the
 state of a tritoxide.
   The sulphurets whose  metals have  little affinity for
 oxygen, act in the air as in close vessels ; they decom-
 pose partially or wholly, and the metal is reduced.  This
 decomposition of sulphurets whose metals are very oxi-
 dable, and their transformation into sulphates, often takes
 place, naturally or artificially, at the ordinary tempera-
 ture.  Water favours this  change when it can dissolve
 the  sulphate which is formed ;  it is probable  that a part
 of the water is decomposed, and that its oxygen serves to
 burn the sulphur and the metal.  As water dissolves the
 sulphate, it  acts also by exposing and  setting  free  the
 surface of the sulphur, and thus facilitating the access of
 oxyrgen.   The remains of sulphurets of iron are found in
 nature, which have lost their sulphur, and whose metal has
 become oxidized ; this fact appears the more remarkable,
 as this decomposition begins in the  centre  of  crystals,
 while the exterior crust is still in the state of a sulphuret.
  Nitric acid acts upon most of the sulphurets when they
 are in a sub-divided  state ;  it yields to them its oxygen,
 which changes them to sulphates, and becomes itself a
 deutoxide of nitrogen.  Many sulphurets exist in nature,
 in crystals, although in laboratories it is difficult to obtain
 ihem crystallized; the form of these  crystals while they
 preserve their metallic lustre, is usually some modification
 of the cube ; but when they do not  possess this  lustre,
they vary more or less from the  regular system of crystal-
lization.   Many  of   these  sulphurets combine   among
themselves,  and as has been observed, form compounds
in definite proportions, according to  laws analogous, to
 those which  regulate  the composition of salts;  so that
one of these  sulphurets is always electro-negative in re-
lation to the other,  and represents the  acid, while the
electro-positive represents the  base.  Most  of  the sul-
phurets can  be  obtained by direct  process, or by passing
                         39 
458
SUL
 a current of sulphuretted hydrogen  over the saline soli*
 tion of metal, whose sulphuret is sought.   Other methods
 of obtaining them will be pointed out under the head of
 alkaline sulphurets.
   Sulphurets Alkaline.  (Sulfures Alcalins.)  This
 general name is given to combinations of sulphur with
 the metals of alkalies.   As these sulphurets present cha-
 racters which are peculiar to themselves, we have thought
 proper to treat of them in a separate article.
   Since the discovery of potassium and sodium, it has
 been known that sulphur may be combined directly with
 these metals, forming sulphurets of peculiar properties.
 It  has also  for a long  time been  believed that sulphur
 could combine with the oxides of these metals, and form
 sulphurets of oxides ;  but late  experiments by Berzelius
 have demonstrated that  sulphur cannot combine with an
oxidated body, and therefore that the sulphuretted alkalies
do not exist, and that when a salifiable base took sulphur by
the dry method, it became in part reduced, forming a me-
tallic sulphate and sulphuret.  Thus in fusing a mixture
 of sulphur and  the  sub-carbonate of potash,  i of alkali
serves to form the sulphate, and the remaining f lose their
oxygen and  combine with sulphur so as to form the sul-
phuret  of potassium.   Thus the  preparation  known by
the name of liver of sulphur, is a compound  of the sul-
phuret  of potassium and the sulphate of potash.  Sulphur,
as has  been seen, can reduce the oxide of potassium at a
temperature not very elevated ; but the reduction takes
place much more  easily, and  the  sulphuret  forms with
greater, facility by employing  hydrogen and carbon as
deoxygenating bodies.
  Berzelius has obtained many sulphurets of potassium
in  definite proportions.
  1st.  The proto-sulphuret  consists of 1  atom of potas-
sium and 2 atoms of sulphur;  it was formed by reducing
the sulphate of potash by hydrogen. 
SUL
459
  *2d.  1 he bi-sulphuret, which consists of 1  atom of po-
tassium and 4 atoms of sulphur, was formed by pouring
at a red heat, the carbonate of potash,  with a quantity of
sulphur less than it could decompose.
   3d.  The trito-sulphuret, which consists of 1 atom of po-
tassium, and 6 atoms of sulphur, was formed by heating
slowly  the  preceding mixture, until it  melted without
ebullition  or disengagement of gas.
   4th. The quadri-sulphuret consists of 1 atom of potas-
sium  and 8 atoms  of sulphur; this was formed by re-
ducing the sulphate of potash by the sulphuret of carbon.
   5th. The quinto-sulphuret consists of 1  atom of potas-
sium and  10 atoms of sulphur;  this was formed  by fusing
the carbonate of potash with an excess of sulphur, until
carbonic acid was no  longer disengaged.
   Metals  brought in contact with the alkaline sulphurets
in a state  of fusion, take from them a certain quantity of
sulphur and form sulphurets;  if they are in sufficiently
great proportions, the metals can  bring the different sul-
phurets of potassium to the state of a proto-sulphuret.  In
these double sulphurets, the number of atoms of the metal-
lic sulphuret which is produced, is determined by the num.
ber of atoms of sulphur in the sulphuret of potassium.
   The  alkaline sulphurets, when  in contact with water,
dissolve without any  disengagement of gas.  Berzelius
makes two  suppositions as to the  nature of these  solu-
tions ;  it is perhaps difficult to decide which comes nearer
the truth :
   1st.  Whether the water is decomposed by the sulphur,
when the  combustible body is dissolved by the alkali, or
by the radical of the  alkali, when the  metallic sulphuret
is treated with water.
   2d.  Whether the metallic  sulphuret dissolves in the
water  without being  altered; and the sulphuretted hy-
drogen, which the acids drive from the  solutions, forms 
460
S Li  1.
 but at the instant in which the potassium oxidizes, in order
 to unite to the acid.
   According to the first of these hypotheses, the liquor
 contains potash  and sulphuretted hydrogen ; but this lasl
 body cannot be considered as formed of constant propor-
 tions of sulphur and hydrogen.  It would be necessary
 to admit combinations of 2 atoms of hydrogen with 1, 2,
 3, 4, and 5 atoms of sulphur, combinations which would
 constitute  peculiar  compounds,  which that celebrated
 chemist was not able to isolate.  He concluded, there
 fore, that the terms hydro-sulphates, and sulphuretted hydro-
 sulphates are less proper than  those of hydro-sulphurels,
 hydro-bi-sulphurets, &c   But  if it is  admitted  that the
 alkaline sulphurets are dissolved in water, without being
 decomposed, there would not then exist such a series of
 sulphurets of hydrogen ;  but when an acid (undeoom-
 posable by sulphuretted hydrogen) is poured into a solu-
 tion of  a sulphuret, the sulphuretted hydrogen which is
 produced, is formed  by the  presence of this acid, which
 decomposes a portion of water by its tendency to com-
 bine with the oxide formed.  This effect takes place with
 the dry sulphuret,  as well as the solution ;  Berzelius
 seems rather inclined to favour the latter theory.   He does
 not adopt  it exclusively for the sulphuret  of potassium,
 which is deliquescent, but appears to adopt it for the  sul-
 phuret  of  calcium.    He  remarks that  boiling water,
 poured upon a sulphuret of calcium, dissolves but a small
 quantity;  that which  is insoluble changes  neither in co-
 lour nor composition.  He preserved during some months,
 some sulphuret  of calcium  in  a close flask, filled with
 water, yet  this  substance  was not decomposed; now if
this decomposition is really made by water, it appeared
to him that it would of course have taken place, when
even the hydro-sulphuret of lime which  forms is little
soluble  in  water, much more  than  in  barium,  calcium.
 manganese, &c, which decompose water and disengage 
SUL
461
 hydrogen, although the oxides which they form are not
 soluble.
   The  solution of sulphuret of calcium which is  ob-
 tained, is without colour ;  when evaporated  in a vacuum
 over sulphuric acid, it deposites upon the sides of the ves-
 sel  white crystals, which, when  slightly  heated, yield
 their water, and pass  to the  state of a sulphuret of cal-
 cium, like a salt with the water of crystallization, or like
 the  double cyanides of iron  with  potassium, barytes, or
 lime.   Berzelius thought it  also probable that the  sul-
 phuret of calcium  dissolves in water without undergoing
 any alteration,  and combines with the water of crystalli-
 zation only in being decomposed by water and changed
 to a hydro-sulphuret.
   The solution of an  alkaline sulphuret  exposed to  the
 air, gradually absorbs  oxygen and  passes to the  state of
 a hypo-sulphite.  But if the sulphuret is  not at its high-
 est point of sulphuration,  there  remains  in  the  liquor a
 quantity of free potash, as much greater as  the sulphuret
 is less sulphuretted.  The acids destroy the solutions of
 the alkaline sulphurets as  we  have seen.  If we admit
 the decomposition of water, and the formation of a  hy-
 dro-sulphuret, the acid must take the place of the hydro-
 sulphuric  acid (sulphuretted hydrogen) which is disen-
 gaged ;  but  if  we admit  the  solution of the  sulphuret
 without the decomposition of water, then it will be  de-
 composed by the presence  of  the acid in the same quan-
tity as potassium  (supposing  the solution to  be that of
sulphuret of potassium) is  transformed into potash by its
oxygen.   Its  hydrogen then will form with the sulphur,
sulphuretted hydrogen, which disengages as it finds itself
in the presence  of an acid which has a still greater affi-
nity for potash.   Thus supposing the proto-sulphuret of
potassium in  solution in water and in the presence of an
acid ; it will happen that this  sulphuret, composed of 1
atom of potassium and  2  atoms of sulphur, will  decorn.
                         39* 
462
SUL
pose a quantity of water sufficient to  yield 2 atoms of
oxygen, which will  combine with the potassium  to form
potash.  As water is formed of 1 atom of oxygen and 2
atoms  of hydrogen, these 2 atoms of  oxygen combined
with potassium to form potash, will have  set at liberty 4
atoms of hydrogen, which will combine with 2 atoms of
sulphur of the sulphuret of potassium to  form sulphuret-
ted hydrogen, which is disengaged since  the potash is in
the presence  of an acid, for which it has greater affinity.
   If instead of employing  the proto-sulphuret, the bi-sul-
phuret, the tri-sulphuret, &c, are used, all containing the
same quantity of potassium, that  is,  1 atom, it is evident
that the same changes as above described will take place ;
but as the quantity of water decomposed is always  the
same, the quantity  of sulphuretted hydrogen produced
will also be the same, and there  will be  consequently a
deposite of sulphur as much greater, as the sulphur was
in a higher state  of sulphuration.   When the  alkaline
sulphurets are prepared  in the humid  way, we  may, as
has been seen, admit the reduction of the alkali  and the
combination of the  sulphur  with its metal; or we may
say that the water is decomposed, and that  one part of
the alkaline base unites to a compound  of sulphur and
hydrogen, while the other combines with the hydro-sul-
phurous acid which  is at the same time produced.   The
solution in water of the proto-sulphuret of potassium is
regarded by Berzelius as  a sub-hydro-sulphuret, which
he  represents by the sign k +  2 H* S (K is the initial
letter of Kali, which according to Berzelius is potash.**)
When sulphur is digested in this solution, it dissolves.
and by this means is obtained the sulphuret of potassium
at all the degrees until the solution  contains 4 atoms of
hydrogen  and 10 of sulphur for  1  atom of potash, or
K  -f- H4  S10  which is the same combination  as  that

    * For an explanation of these signs see the article Signs Chemical 
SUL
463
formed when the sulphuret of potassium at the maximum,
or the quinti-sulphuret, is  dissolved  in  water.   This
chemist regards as a neutral hydro-sulphuret that which
is formed of k -f 4 H1 S, or which contains a quantity
of sulphurretted  hydrogen, precisely  double  that con-
tained in the sub-hydro-sulphuret.   When pulverized
sulphur is mixed in a  concentrated solution of this neu-
tral hydro-sulphuret, the result even at the ordinary tem-
perature, is a violent effervescence, and a disengagement
of sulphuretted hydrogen  gas ;  the sulphur dissolves  and
the solution  takes an  orange colour.  If sulphur con-
tinues to be  added until the gas is no longer disengaged,
the combination is obtained which contains the most  sul-
phur, or  k + H4 S10  ; so that 8 atoms of sulphur expel
2 atoms  of sulphuretted hydrogen, or half the  hydro-sul-
phuric acid  contained in  the salt.  The alkaline hydro-
sulphurets have the property of dissolving a  certain num-
ber of metallic  sulphurets, viz.  those of metals whose
oxides are electro-negative, or can perform the part of
acids, as the sulphurets of arsenic, tungsten, molybdenum.
antimony, dec ; all are soluble in the hydro-sulphurets, and
in the caustic alkaline  sulphurets.  Their solution  in the
last (except  that of the sulphurets of antimony and  tita-
nium) is precipitated  by  the  acids, without any  disen-
gagement of sulphuretted hydrogen, as  they had in dis-
solving experienced no alteration.
   Sulphuret of Antimony.    (Sulfure  d'Antimoine.)
Proto-sulphuret.   Of a  bluish gray colour, shining, usually
confusedly crystallized, and forming masses more or less
voluminous,  brittle and easily.reduced to powder.   Its
specific gravity is 4-3.  Exposed to  fire, it fuses more
easily than  antimony, and is not decomposed at an ele-
vated temperature.  If heated in contact with the air, it
absorbs oxygen, disengages sulphurous acid, and unless
the temperature is too high it forms a sub-sulphate of an-
timony.  The proto-sulphuret of antimony  exists in na- 
164
S I  L
 ture in the veins of different  minerals, and sometimes
 itself forms important veins.  It is  found in crystalline
 masses, composed of interlaced acicular prisms, in the
 lamellar and compact state.  Sometimes these crystals
 are rather separated, but they are always very fine, and
 united by their bases so as to form groups, in which may
 be observed crystals derived from the rhomboidal form.
 It often combines with other sulphurets, particularly those
 of silver and copper.  It is composed of 27 parts sulphur
 and 73 of antimony,  or  1 atom of antimony and 3 atoms
 of sulphur.  This sulphuret can be prepared directly,
 but it is much easier to obtain it from ores.   It is  em-
 ployed in the preparation of some active medicines.
  Hydrated proto-sulphuret.   Most  chemists at present
 agree in regarding the kermes  mineral as a proto-sulphu-
 ret of antimony, containing the quantity of  water which
 would  be necessary for transforming the  metal to  an
 oxide,  and the  sulphur to sulphuretted hydrogen; some
 chemists consider it as a hydro-sulphate.  It is a beauti-
 ful red powder, insoluble in water,  partly soluble in the
 alkalies ; entirely soluble in hydro-chloric acid.   It is ob-
tained by melting in a crucible 2 parts of the sulphuret
of antimony with  1 part of potash ;  the mass is cooled,
pulverized, and boiled in  12 times its weight of water ;
the boiling liquor is filtered, and the  kermes is deposited
on cooling.  This is the  dry  way;  but  the kermes ob-
tained does not possess that  fine colour which it  does
 when prepared as follows:  Dissolve  1 part of pure sub-
 carbonate of soda in water, boil the solution, deprive it
 of air ; add gradually 2| parts of pulverized sulphuret of
 antimony, taking  care  to  agitate the mixture.   Boil for
 half an hour, and filter ;  the liquor is then cooled, and the
 kermes deposited.  After this  it is  washed, dried  by a
 gentle  heat, and pressed.  Soda is to  be   preferred to
 potash,  giving a  much finer  colour,  but  why is not
 known. 
SUL
465
   Sulphuret  of Ammonia  Hydrogenated.  (Sulfure
d'Ammoniaque  Hydrogene.)   Hydro-sulphuret of ammo-
nia.  It is  a thick liquid, of a reddish brown colour, of
an odour and taste very disagreeable.   Exposed to the
action  of  caloric, without access of air,  it  produces
sulphur  and a hydro-sulphate which  volatilizes ; when
treated by water, the same products are  obtained.  This
sulphuret is obtained by heating in a  retort "a mixture of
lime, sulphur, and hydro-chlorate (muriate) of ammonia ;
a  yellowish, very volatile  liquor  is formed, which  con-
denses in a  receiver.  This liquid is transferred to a flask
with its weight of the flowers of sulphur, of which it dis-
solves the greater part, becoming thick and  coloured ;
this constitutes the hydro-sulphuret of ammonia.  In this
operation, the chlorine  contained  in the hydro-chlorate
of ammonia, decomposes a portion of the lime, forming
the chloride of calcium  ; the oxygen of the lime decom-
posed, combines with 1  part of sulphur, in order to  form
hypo-sulphuric acid, which unites  to the  portion of  lime
not decomposed;  while the remainder of the sulphur,
the hydrogen of the hydro-chloric acid, and the ammonia
of the hydro-chlorate, unite to  form a sulphuretted hydro-
sulphate, which is saturated by being mixed with an ex-
cess  of sulphur.  This hydro-sulphuretted  sulphate  of
ammonia  (sometimes  called   sulphuret) was  formerly-
called Boyle's fuming liquor, from the name of its disco-
verer, and from  the circumstance of its exhaling thick
white fumes.
  Sulphuret of Arsenic. (Sulfure d'Arsenic.) Arsenic
combines easily  with sulphur, and by suitably heating
different quantities of sulphur with the metal, a number
of sulphurets may  be obtained.   It is however probable
that these sulphurets are only mixtures of the proto and
deuto sulphurets, in different proportions.  The artificial
sulphuret of arsenic is obtained by passing a current of
sulphuretted hydrogen into  a solution of the deutoxide of 
466
SUL
this metal; it precipitates in yellow flakes.  It may also
be obtained  by sublimation, since the two bodies which
compose it are volatile.   It corresponds to the deutoxide
of arsenic, and is therefore a deuto-sulphuret.  It exists
in nature.  It is known by the  name of orpiment.  It is
yellow, non-metalloid, but shining, lamellar, and flexible ;
it is seldom found  crystallized,  but usually in  masses
which divide" parallel to the axis of an oblique rhomboidal
prism, which is its primitive form.  This  lamellar state
serves to distinguish it from the artificial orpiment, which
is always compact; both consist of 39 parts sulphur to
61 arsenic, or of 1 atom of arsenic and 3 atoms of sulphur.
  The proto-sulphuret or  realgar can equally  be obtained
by artificial means, either by combining proper quantities
of sulphur and arsenic, or by heating the orpiment or
deuto-sulphuret.  As it  exists  in nature,  it is a red sub-
stance, without metallic lustre,  compact, or sometimes in
crystals more or less determinate, derived from an oblique
rhomboidal  prism.   Its  specific gravity  is  3-3.  It is
formed  of 30 of sulphur, and 70 of arsenic, or of 1 atom
of arsenic and 2 atoms  of sulphur.  The sulphurets of
arsenic  being insoluble in water, are much less poisonous
than the  soluble compounds  of this  metal; these are
easily known by the garlic-like  odour which they  give off
when thrown upon  burning coals, and  on -heating them
with an excess of soap in a little glass  tube, solid  arsenic
may be obtained.
   Sulphuret of Barium.  (Sulfure de Barium.)  Of a
grayish  white, forming  crystalline masses, soluble in
water, and  producing a colourless solution.  Muriatic
acid disengages  much sulphuretted hydrogen from this
solution, without giving place to any deposite of sulphur.
It is very little altered by the air even by elevating the
temperature.   It can be burnt only by  heating it with the
nitrate of potash; the result  is the sulphate of barytes.
 The chlorate of potash does not produce the same effect. 
SUL
46/
 The sulphuret of barium is obtained by exposing the sul-
 phate of  barytes and charcoal to an intense heat.  See
 Alkaline Sulphurets.
   Sulphuret of Bismuth.   (Sulfure de Bismuth.) Of a
 yellowish or bluish  gray, susceptible of crystallizing in
 needles, which cross and form masses similar in appear-
 ance to the sulphuret of antimony. It is very brittle, less
 fusible  than bismuth, easily absorbs oxygen by the aid of
 heat, producing if the heat is not too great, sulphuric acid
 and a sulphate.   This sulphuret  is obtained by fusing
 sulphur with bismuth ; it seems difficult by this means to
 obtain it pure; for the different analyses  which have been
 made of it, have not given the same results.   It exists in
 nature but in small quantities.   It is yellowish, has a
 metallic  lustre,   crystallizes-  in  rhomboidal  acicular
 prisms.   Its specific gravity is 6.  It consists of 18 of
 bismuth, and 82 of sulphur, or of I atom of metal and 2
 atoms of sulphur.
   Sulphuret of Cadmium. (Sulfure de Cadmium.) Ac-
 cording to M. Stromeyer, this sulphuret is of a beautiful
 orange colour, fusible  only at a white heat, susceptible of
 crystallizing by a careful evaporation in micaceous, trans-
 parent lamina of a fine yellow colour.  Exposed to the
 action of  heat, it  becomes brown, afterwards  crimson,
 and resumes its natural colour on cooling.  It may be  ob.
 tained by heating a mixture  of sulphur and cadmium;
 but can be procured more  easily bv precipitating a salt
 of this metal, by sulphuretted hydrogen, or reducing  the
 oxide of cadmium by sulphur.  It consists of 100 of cad-
 mium, and 28-172 of sulphur.
   Sulphuret of Calcium.  (Sulfure de Calcium.) White,
opaque,  infusible, dissolves  very sparingly  in water; it
 transforms itself into a sulphate of lime when exposed in
 a humid atmosphere ; it is, like the sulphate of barytes,
obtained by treating the sulphate oflime with  carbon at
 a very elevated temperature. 
168                   SUL
    Sulphuret of Carbon.  See Carburet of Sulphur.
    Sulphuret of Cerium.   (Sulfure de Cerium.)  This
 sulphuret is scarcely known;  the hydro-sulphuret of am.
 monia precipitates its solutions brown, but the precipitate
 passes to a deep green, as more of the agent is added ;  on
 heating it in contact with the air it burns, producing sul-
 phurous  acid,  and  giving  the oxide  of cerium for  a
 residue.
   Sulphuret of Chlorine.   {Sulfure de Chlore.)  See
 Chloride of Sulphur.
   Sulphuret of Chrome.  (Sulfure de Chrome.)  Little
 is known  of it, except that it  exists, and is obtained  by
 heating a mixture of sulphur and the chloride of chrome,
   Sulphuret of Cobalt.  (Sulfure de Cobalt.)   It may
 be obtained by heating a mixture  of sulphur and the oxide
 of cobalt,  but more easily through the medium of potash ;
 it  then forms  a double sulphuret, of a yellowish white,
 which easily  crystallizes,  but  decomposes with diffi.
 culty.
   Sulphuret of Columbium.   (Sulfure de Columbium.)
 Vs  sulphur appears  to  combine with  all metals,  it  is
 probable  that  a sulphuret of columbium  does exist,
 though it has not been obtained.
   Sulphuret of Copper.  (Sulfure de Cuivre.)   Proto-
 sulphuret.   Solid, brittle, black, or of a deep gray, much
 more fusible than copper, easily absorbs oxygen from the
 air by the aid of heat, yielding different products  ac-
 cording to the  temperature.   It is  obtained by fusing
 copper and  sulphur together;  combination  takes place
 on  their  inflaming;  this inflammation is most intense
 when 8 parts of metal are combined with 3  parts of sul-
 phur.  The sulphuret of copper exists in nature, and ap-
 pears in fragments of a steel gray colour, resembling  that
 which is  artificially obtained.   Its specific gravity  is
about 5; it is  sometimes  found crystallized  in forms de-
rived  from a regular hexahedral  prism.   It is composed 
SUL
469
 of 20 parts of sulphur, and 80 of copper, or 1 atom  of
 each of the constituents.  It is found in combination with
 the sulphurets of antimony, silver, bismuth, tin,  and par-
 ticularly with the sulphuret of iron ;  this last  combination
 \fs known by the name of copper pyrites, or pyritous copper.
 It exists in masses more or less voluminous, of a gold
 colour, sometimes iridescent.  Its  crystals, which  are
 much more rare than those   of iron  pyrites,  are  derived
 from the  tetrahedron.   This  substance, and the  gray
 copper which seems to be  a mixture of this pyrites with
 some other sulphurets, are considered as the two  most im-
 portant copper ores.  The last often contains silver, pro-
 bably existing in it as a sulphuret.
   The deuto-sulphuret is  little known;  it may easily be
 procured by passing a current of sulphuretted hydrogen
 into the solution of a deuto-salt of copper.
   Sulphuret of Gold. (Sulfure d'Or.)  Is little known ;
 by pouring the solution  of an alkaline  sulphuret into a
 solution of gold, a black  precipitate is  obtained, which
 appears to  be  a sulphuret.   A precipitate is also obtained
 by heating  a mixture of 3 parts of potash, 3  parts of sul-
 phur, and  one part of gold, and precipitating  by  an  acid ;
 the precipitate consists of 100 of metal and 24-39 of sul-
 phur.
   Sulphuret of Iodine.  (Sulfure d'lode.)   By slightly
 heating a mixture of sulphur and iodine, a brilliant radi-
 ated mass  is obtained, resembling the sulphuret of anti-
 mony and  which easily decomposes.   This is the sulphu-
 ret of iodine.
  Sulphuret of Iridium.    (Sulfure d'Iridium.) Is ob-
tained by heating intensely a mixture of sulphur, muriate
of ammonia, and iridium.  A sulphuret is obtained which
 easily decomposes by contact with  the air.   According
to Vauquelin,  it  consists of  100 of  metal,  and  33-33 of
 sulphur.
                         40 
170
SUL
   Sulphuret of Iron.   (Sulfure de  Fer.)   By heating
 different  proportions of sulphur and iron filings, a black
 sulphuret of iron is obtained ;  this is brittle and destitute
 of metallic lustre, and much more fusible than iron  ; its
 cohesion being less than that of natural sulphurets, it easi-
 ly decomposes by the acids ;  the result of this decompo-
 sition is a protoxide of iron, and sulphuretted hydrogen,
 which is  disengaged.   The proportions of sulphur and of
 iron in this sulphuret vary in a peculiar manner, and  ren-
 der it probable that it is only a mixture of two sulphurets
 in uniform proportions.   Mineralogists admit  three  spe-
 cies of sulphuret of iron ; chemists admit but two, founded
 upon the  proportion of their constituent principles.
   The proto-sulphuret, or magnetic sulphuretted iron is of a
 yellowish, often a reddish brown ; its  fracture is rough ;
 it is affected by the magnet.  Its  crystals are often hexa-
 gonal  tables,  sometimes  approaching  to  the rhomboidal
 prism ; it appears to belong to the primitive earths.   It is
 composed of 37  parts of sulphur,  and 63 of iron, or 1
 atom of iron and  2 atoms of sulphur ; but it is mixed with
 a certain quantity of per-sulphuret.
  The per-sulphuret, also known by the name of marcas-
site, martial pyrites, dec, is of a brass yellow,  and pos-
sesses  metallic lustre.   It gives off sparks when  struck
by steel, at the same time diffusiug a sulphureous odour,
which becomes still stronger on exposing the  metal to the
heat of burning  coals.   By the  blow  pipe this sulphuret
is converted into a metallic globule, attracted by the mag-
net.   Its specific  gravity is from 4 to 4-7 ; it is suscepti-
ble of a high polish.  Its primitive form may be the cube
or octoedron, although it appears in several other forms.
These  pyrites often contain different substances, as arse-
nic, silver, gold, dec ;  such as contain gold usually have
the faces of their crystals striated. There exists a variety,
which  mineralogists  regard  as  a distinct species;  this
is of a pale colour, sometimes approaching to steel grav. 
SUL
471
It is not affected by the magnet.  This variety passes
more easily than  the  other  to  the state of a sulphate;
and this change which often occurs in nature, also takes
place in mineralogical collections, when the sulphuret is
exposed to the air ; it is very remarkable that this change
commences at the  centre and  gradually extends to the
outer parts of the mineral.   This variety is chiefly used
for obtaining the sulphate of iron ;  it is common in con-
nection  with  argillite  and beds of lignite.   The other va-
riety is one of the most abundant  minerals;  it is found
in the  primitive  as  well as the  newest formations ; it is
often the only metallic substance  which is found in veins
of quartz.  It is more rare in volcanic countries.  Both va-
rieties consist of 54 parts of sulphur, and 46 of iron, or
1 atom of iron, and 4 of sulphur.  Every analysis has  not
given this proportion ; sometimes the  proto-sulphuret  has
been found in combination.
   Sulphuret of Lead.  (Sulfure de Plomb.)  Galena.
The proto-sulphuret is obtained by melting in a crucible, a
mixture of lead and  sulphur.  Combinatiou  takes place
with a disengagement of caloric and light; the result is,
a brittle, shining sulphuret, of a  dark bluish gray, much
less fusible than lead.   Exposed  to a very elevated tem-
perature,  in contact with the air, it  decomposes, giving
rise to sulphurous acid, lead, and a  sub-sulphate ;  a part
of the latter  volatilizes.   It consists of 100 of the metal
and 15-54 of sulphur.  The sulphuret of lead  exists in
nature in great quantities, in masses of a lead gray metal-
loid, easily separated, and  dividing parallel  to the faces
of the cube, which is its primitive form.  This sulphuret
 contains the sulphurets  of antimony,  bismuth, and silver;
 that which contains the greatest quantity of this last, is in
 general the  most confusedly crystallized,  or  offers very
 small crystalline faces.   The miners call the variety ga-
 lenc a petites facettes.  The natural sulphuret of lead con-
 sists of 13 parts of sulphur, and 87 of metal  ; or 1 atom
 of lead, and 2 atoms of sulphur.  It  is the only mineral 
172
SUL
wrought for the purpose of obtaining lead.  According to
Thomson, there is in nature, another sulphuret of lead, of
a colour more clear and brilliant, which burns with  a blue
flame, and which contains 25 parts of sulphur to 100 of
metal;  this would be the deuto-sulphuuret.
   Sulphuret of Manganese.   (Sulfure de Manganese.)
Black, pulverulent,  much more fusible than manganese.
Red heat does not decompose it when kept from  the air  ;
oxygen is absorbed at that temperature, and the sulphuret,
disengaging sulphuric  acid, becomes a  sulphate.   It is
procured by heating intensely a mixture of charcoal and
the sulphate of manganese.   It is  found in nature only in
small  masses  not crystallized, or in blackish pellicles in
connection with the carbonate of manganese and telluri-
um.   That which is obtained artificially is formed of 10 0
of manganese, and  56-32 of sulphur.
   Sulphuret  of  Mercury.   (Sulfure de  Mercure.)
When a current of sulphuretted hydrogen is passed over
a mercurial solution, a sulphuret is formed, which is pre-
cipitated either by a proto or a deuto salt; but the  preci-
pitate obtained in the  solution  of the   proto-salt  when
sufficiently compressed yields globules of mercury ;  this
is not the case when a deuto-salt is employed.  M. Gui-
bourt, by whom these experiments  were made, supposing
that the  deuto-sulphuret thus obtained by sublimation may
be  transformed into a red sulphuret without losing its
constituent principles, believes that there is but one sul-
phuret of mercury, and  that what is regarded as  a  proto-
sulphuret is a mixture of the  red  sulphuret  and  of pure-
mercury.   It seems however probable  that  since there
are two oxides of mercury, there are also  two sulphurets  :
but it is very possible  that, like the protoxide, the  proto-
sulphuret  may be  easily decomposed.  The proto-sul-
phuret is black; it is known by the names ethiops mineral,
mercurial ethiops, die  It may be obtained, as has already
been  observed, by passing  a  current  of  sulphuretted 
SUL
173
hydrogen into a solution of the proto-nitrate of mercury ;
but it is usually  procured by triturating in a  porcelain
mortar a mixture of sulphur and mercury, until the mix-
ture appears of a blackish  green colour;  it is then put
into a cup, where the combination  becoming  more inti-
mate, the sulphuret becomes more  and more  black.   It
is also prepared by adding mercury to sulphur in a state
of fusion, and  agitating the mixture ;  this mode of pre-
paration gives the sulphuret a violet tinge.   When pre-
cipitated by sulphuretted hydrogen, it is formed of 100 of
metal and 8-2 of sulphur, or of 1  atom of each constituent.
It is employed in medicine.
  The deuto-sulphuret is of a red colour approaching to
violet when it is in  a  mass ; when  pulverized, it is of a
beautiful scarlet red ;  it is insipid, unalterable by the air,
insoluble in hydro-chloric acid. When heated sufficiently,
it  inflames, and burns with a  blue flame, giving place to
sulphurous acid and a revivification of the mercury.   If
reduced  to vapour, and made to pass through  a heated
tube of porcelain, it  detonates;  most of the metals and
lime decompose  it; upon this  property is founded  the
extraction  of mercury.   The deuto-sulphuret, precipi-
tated by sulphuretted hydrogen  from a solution of  the
deuto-nitrate, is formed of 100 of mercury and  16-4 of
sulphur, or  1 atom of mercury and 2 atoms of sulphur.
The red sulphuret of mercury is known by the names of
cinnabar, vermilion, die   This  is  formed by triturating
in a porcelain mortar 300 parts of mercury with 68 parts
of sulphur, and moistening the mixture with a solution of
potash;  the ethiops  mineral first forms;  more of  the
solution of potash being  added,  it is heated  and evapo-
rated; the black colour of the  mixture first changes to
brown and then to red.  When the mass is of the con-
sistence of jelly, the  colour  becomes more  and more
brilliant; when arrived at its greatest brilliancy, the ves-
sel containing it is taken from the  fire ; if kept too long
                         40* 
174
S U L
exposed  to-the heat, the  colour would return to a duty
brown.   The  deuto-sulphuret of mercury exists in con-
siderable  quantities  in nature; it  is  from this that the
metal is principally extracted ; it is sometimes  compact,
earthy, and sometimes fibrous.  Its specific gravity is 7 ;
that of the artificial sulphuret is greater.   Native cinna-
bar is usually found in secondary formations.
  Sulphuret of Molybdenum.   (Sulfure de Molybdine.)
A gray metalloid, more fusible than molybdenum, absorbs
the oxygen of the air by the aid of heat, transforming
itself into sulphurous and molybdic  acids which volatilize.
It is obtained  by heating 1 part of molybdic  acid with 5
parts  of sulphur.   It is  found  in nature  in  unctuous
masses  a little resembling  plumbago.   These  masses
often  present a leafy structure ;  these  leaves are a little
flexible.   It is also found in scales disseminated in certain
rocks ; it is seldom found  crystallized ; when it is so, the
crystals are in hexahedral prisms.   Its specific gravity is
4-6.   It consists of 40 of  sulphur and 60 of  metal, or 1
atom of metal and  2  atoms of sulphur.
  Sulphuret of Nickel.   (Sulfure de Nickel.)   Of a
yellowish white, decomposable  by heat,  in contact with
the air producing sulphurous acid and a sulphate which is
decomposed by a  higher  degree of heat.   It is not at-
tracted  by the magnet.  It is  obtained by heating a
mixture of sulphur and nickel.
  Sulphuret of Palladium.  (Sulfure de  Palladium.)
1'alladium  unites  readily  with  sulphur.   If  when  it  is
highly heated sulphur is added,  the mixture  immediately
fuses, and the  sulphuret  remains  liquid even  at a dark
red heat.   It is paler than the pure metal, and very brit-
tle.  By heat, and even by leaving it for a long time ex-
posed to  the  air,  the sulphur dissipates, and the metal
remains pure.  According to Vauquelin, it consists of 100
of the metal and 24 of sulphur. 
SUL
475
   SuLPnuRET of Phosphorus.  See Phosphuret of Sul-
phur.
   Sulphuret of  Platina.   (Sulfure de  Platine.)   h
appears that sulphur can  combine with platina in three
proportions;  some chemists however admit  but two sul-
phurets.   The proto-sulphuret is of a bluish gray and  of
an earthy appearance, yet  it leaves metallic traces when
rubbed upon  paper.   It is  inodorous, insipid, and  rough
to the touch.  Its specific gravity is 6-2.   It is a non-
conductor of electricity.  It is decomposed by zinc filings
with the aid of heat.  It is  obtained by heating, in a glass
tube deprived of air, a mixture of equal parts  of sulphur
and  platina.   According to Davy, this sulphuret consists
of 100 of metal and  19-04  of sulphur.
  The deuto-sulphuret of platina is produced by precipi-
tating platina from its solution  by sulphuretted hydrogen.
and heating the  precipitate in a close vessel.   It  is pul-
verulent, much lighter than platina, insipid, of a bluish
black, staining the fingers  and paper  like  plumbago.-  It
is formed of 100 of metal and 28-21  of sulphur.
  The per-sulphuret  of platina is obtained by heating in a
glass retort a mixture of 3 parts of the ammoniacal hydro-
chlorate of platina and 2 parts of sulphur ;  the mixture is
gradually heated  to redness,  and  this temperature  is
maintained until all the volatile part is disengaged.  This
sulphuret is of a dark iron-gray;  when in a mass, it has
a slight metallic lustre ; it  is soft to the touch, and  spots
paper like plumbago.  Its  specific gravity is 3-5;  it is a
non-conductor of electricity, and maintains without fusing
a very high temperature.   If heated with zinc filings, a
combination ensues ;  when heated to redness in the open
air, the sulphur separates,  and the platina  remains  pure.
According to Davy,  it is formed of 100 of metal and 38-8
of sulphur.                                           *
   Sulphuret of Pluranium.   A transparent yellowish 
176
SUL
substance when first  formed, changing afterwards  to a
gray colour with a metallic lustre.
   Sulphuret of Poiassium.   (Sulfure de Potassium.)
The proto-sulphuret is obtained by inlensely heating the
sulphate of potash in  a crucible lined with charcoal,
(creuset brasque); all  the oxygen contained in this salt is
disengaged  in combination with carbon, and an alkaline
sulphuret remains ;  this is flesh-coloured, translucid, and
dissolves in water with  an elimination of caloric.   This
sulphuret when pure  is  burned with difficulty; but in-
flames almost spontaneously when it contains a sufficient
quantity of powdered charcoal ;  thus if a mixture of
lampblack and the sulphate of potash be strongly heated,
a  compound is obtained which  becomes  ignited  as soon
as moistened.   There are, as was remarked  under the
head of the alkaline sulphurets, many  sulphurets of pot-
ash.  Potash may easily be made to combine directly
with sulphur;  but in this case it is rare to obtain sulphu-
rets whose proportions are uniform, and which do not con-
tain an excess of one  or the  other of  the constituent
principles.   The sulphuret of potassium  is employed in
medicine, but never in an unmixed  state.   That prepara-
tion which  is known  by the name of liver of sulphur,
(sulphuret of potash,) is a mixture of the sulphuret of po-
tassium, and the sulphate of potash.
   Sulphuret of  Rhodium.   (Sulfure  de Rhodium.)
This may be procured by heating  in a close crucible a
mixture of  sulphur and ammoniacal hydro-chlorate of
rhodium ; the sulphuret thus obtained is more fusible than
the metal, and  is easily decomposed  by heating  in the
air.  This  sulphuret,  according to Vauquelin, is formed
of 100 of metal and 26 of sulphur.   Berzelius considers
it a deuto-sulphuret; he  admits three  sulphurets of this
metal; the first containing 13.44, the second 26-88, and
the third 40-32 of sulphur, numbers which  are  exactly
multiples of 13-44 by 2 and 3. 
SUL
477
   Sulphuret of Selenium.   (Sulfure de Selenium.)  It
is probable, since sulphur and selenium unite in all pro-
portions, that there are several sulphurets of this metal.
The sulphuret of selenium is obtained by passing a cur-
rent of sulphuretted hydrogen over a solution of selenic
acid.  The sulphuret remains in suspension in the liquor,
but by adding some drops of muriatic acid, and heating
it lightly,  it separates in the form  of a yellow elastic
mass, fusible at a  degree of heat a  little above that of
boiling water.   This sulphuret volatilizes at a more ele-
vated temperature,  and on distillation gives a reddish yel-
low liquor resembling melted orpiment.  When heated in
the air it absorbs oxygen, transforming itself into sulphu-
rous acid, and an oxide of selenium.   It dissolves easily
in the  alkalies  and the alkaline sulphurets  The liquor
deposites it when an acid is added.   It consists of 100 of
selenium, and 60-75 of sulphur.
   Sulphuret of  Silver.   (Sulfure d'Argent.) Solid,
black, or of a deep violet colour, more fusible than silver,
may be cut with a knife,  is susceptible of crystallization
in little needles.   It is obtained by heating in a crucible
very thin leaves of silver with  sulphur.  The combina-
tion commences soon after fusion takes place.   This sul-
phuret is found  in  nature.   It is compact, shining, of a
lead gray,  ductile, crystallizes in cubes, octoedrons, and
cubic octoedrons.   It is  observed also in capillary fila-
ments.   Its specific gravity is 7.  It consists  of  13 of
sulphur and 87 of silver, or 1 atom of silver and 2 atoms
of sulphur.   It forms a combination with the sulphuret of
arsenic, and also  with the sulphuret of antimony;  the
latter is known by the name  of red  silver; its  crystals
differently modified are derived from an obtuse rhomboid ;
it consists of 32 of sulphuret of antimony, and 68 of sul-
phuret of silver; or 2 atoms of the former, and 3 of the
latter. 
178
SUL
  The black  spots which may be seen upon silver when
brought in contact with substances which contain sulphur.
are produced by the formation of sulphurets.
  Sulphuret of Sodium.   (Sulfure de  Sodium.)  Sul-
phur is easily combined with sodium by the aid of heat;
caloric and light at the same time are eliminated ;  the re-
sult is a sulphuret of a deep gray colour, which inflames
when heated  in contact  with the air, and  becomes a
sulphate of soda.  This sulphuret may also be obtained
by heating the sulphate of soda in a crucible with char-
coal ; this is probably more pure than  that prepared by
the direct  process.   Sodium  like  potassium can  form
many sulphurets.
  Sulphuret of Strontium.  (Sulfure  de  Strontium.)
Is obtained by intensely heating the sulphate of strontium
in a  crucible  with charcoal  (creuset  brasque).    It is
white, granular, friable, and resembles the sulphuret of
barium.
  Sulphuret of Tellurium.   (Sulfure de Tellure.)  Is
little known;  it may  be obtained by  melting  tellurium
with sulphur.   It is of a lead  gray, of a crystalline and
radiated texture ; it burns with a green flame when thrown
upon ignited coals.  It is more fusible than tellurium.
  Sulphuret  of  Tin.    (Sulfure d'Etain.)   Sulphur
combines  with tin  in two proportions.   The  proto-sul-
phuret is of a lead gray colour, a metalloidal appearance,
and susceptible of crystallizing in brilliant scales.  It is
less fusible than tin, absorbs oxygen by the aid of heat,
producing sulphurous  acid  and a sulphate, which  a  more
elevated temperature decomposes.   Concentrated hydro-
chloric acid changes it to the oxide of tin and sulphuret-
ted hydrogen.   It is  obtained by heating a mixture of
2 parts  of sulphur and 3 parts of tin.   It consists of 100
of tin,  and 27-234 of sulphur.  It  exists in nature in
^mall quantities, and  always combined with  copper py-
rites.  The deuto-sulphuret is  in the form of light  gold- 
SUL
179
coloured scales, which easily adhere to other bodies.  If
exposed to the action of caloric, it  leaves a portion of
the sulphur, and  becomes a proto-sulphuret.   Nitric and
muriatic acids have no action upon it, but it  is dissolved
by a mixture of these two acids.   A strong solution of
potash also dissolves it by the aid of  heat, giving a green
solution, from which  acids  precipitate a  yellow powder
which appears to be the  sulphuret of tin.
   The deuto-sulphuret is used in  bronzing  and for rub-
bing  the cushions of electrical  machines.  It has been
called massive gold, mosaic gold, &c  It is generally ob-
tained by heating for  a long time in a crucible, a mixture
of tin, sulphur, mercury, and  muriate of ammonia.  An
alloy is made with 2 parts  of tin, 1 part of muriate of
ammonia, and 1} parts of sulphur ;  this is exposed to a
mild heat until the combination is  completed, which is
usually in about three quarters of an hour.   The deuto-
sulphuret of tin consists  of  100 of metal and 52-3 of sul.
phur.
   Sulphuret of Titanium.   (Sulfure  de  Titane.)   Is
obtained by heating  intensely a mixture of  sulphur and
the oxide of titanium.  Its properties are scarcely known.
   Sulphuret of Tungsten.   {Sulfure  de Tungstene.)
Colour grayish black, pulverulent; it takes a fine metallic
brilliancy on being rubbed with a polishing stone.   It is
obtained by heating intensely with charcoal a mixture of
tungstic acid and sulphuret of mercury.  According to
Berzelius, the sulphuret  consists of 100 of metal and 33-26
of sulphur.
   Sulphuret of Uranium.   (Sulfure d'Urane.)   This
combination is little known.  Klaproth mixed the perox-
ide  of uranium  with double its weight  of  sulphur;  he
heated the mixture in a  retort till the greater part of the
sulphur was driven off;  the residue was a blackish brown
 compact mass ;  by increasing the heat the remainder of
the sulphur separated, leaving the uranium in the  metallic 
480
SUN
 state in the form of a black and heavy powder.   The
 experiments of Bucholz, although  made  in  a different
 manner, exhibited  nearly the same results.  He boiled
 even to dryness a  mixture of sulphur  and the oxide of
 uranium in an alkaline solution.  The residue was heated
 to redness, and afterwards treated with  distilled water; a
 dark  powder was  precipitated;   the  solution  presented
 crystals of little needles of a red colour. The compound
 thus  obtained, by  dissolving in hydro-chloric acid, af-
 forded sulphuretted  hydrogen ;  this proves that it was a
 sulphuret of uranium and not a sulphuretted oxide.
   Sulphuret of Zinc.  (Sulfure de Zinc.)  It has not
 a metallic lustre, is  less fusible than zinc ; exposed to the
 action of heat in contact with the air, it absorbs oxygen,
 produces sulphurous acid and a sulphate.  This sulphuret
 is obtained  by pouring  into a  solution of  a chloride of
 this metal the solution of an alkaline sulphuret.   It  may
 also  be  obtained by heating a mixture of sulphur and the
 oxide of zinc, and  by calcining  the sulphate of zinc  with
 charcoal.   It is with  difficulty prepared  by employing
 sulphur and metallic zinc, it being necessary that the
 temperature  of  the  latter  should be very elevated, and
 the quantity of the sulphate  produced is then small.  The
 sulphuret of zinc exists in nature in great quantities, and
 presents itself in non-metalloid masses whose colours are
 very variable.   Its  specific  gravity is 4-16 ; its  primitive
 form  is the  rhomboidal dodecahedron.  Some  varieties
 are fibrous,  others granular; there are  some which  con-
tain sulphuret of arsenic.  The  natural sulphuret of  zinc
is  called blende; it  consists of  33 of sulphur  and 67  of
metal, or 1 atom of zinc  and 2  atoms of sulphur.   It  is
used in  preparing the sulphate  of zinc, and in  making
brass ; in the latter  case, however, calamine, or  oxidated
zinc, is  most generally employed.
   Sun.   (Soleil.)   The ancient  chemists gave this name
to gold, which they called the king of metals, and which
had the colour of the sun. 
T  A N
481
  ^uper Salt.  A  compound of an  acid  and base in
which the acid is in excess.
  Synthesis.  (Synthese.)   An operation the reverse of
analysis ; in the  latter the elements of a substance are
separated in order to ascertain their nature and the pro-
portions in which they are combined ;  synthesis, profiting
by the knowledge derived from  analysis, consists in re-
uniting in their proper proportions the elements which
form bodies, and  placing them in such circumstances as
will favour their  combination and produce  the  desired
compound.   Most bodies are susceptible of analysis, but
there are many which cannot be reproduced  by synthesis.
(The causes which oppose this reproduction are  treated
of under the article Affinity.)  We are able by synthesis
to imitate most of the compounds in the inorganized king-
doms ;  but  nature, or  rather the Author of nature,  can
alone perfect the compounds of the organic  kingdom.
   Systems  Atomistic.   (Systemes Atomistiques.)   See
 itom.


                          T.

   Fannin.    This is  a pecujiar principle which is ex-
tensively diffused in the vegetable  kingdom ;  it is obtained
pure with difficulty, on account of its tendency to form
combinations with the other principles  contained in the
substances  in which it exists.  Artificial tannin however
can be produced by treating oil and indigo with nitric
acid, or the resins  and many other substances by sul-
phuric  acid.  Tannin is  solid, brown, inodorous, brittle,
of a very astringent taste, and crystallizable.
   When exposed to the action of caloric, it swells, pro-
duces  an acid liquor, and gives for a residue an abundant
charcoal:  artificial tannin gives also the  deutoxide of
nitrogen.  It is soluble in water and insoluble in acohol;
                          41 
182
T  A R
 it combines with most of the acids and oxides;  the com-
 pounds which result are little soluble, and  for this reason
 tannin precipitates most of the saline  solutions except
 those of the alkalies.  Natural  tannin is decomposed  by
 nitric acid, the artificial  is not;  but of all  the properties
 of tannin, the most remarkable and most useful is that of
 forming imputrescent, tough,  and  insoluble  compounds
 with many animal  substances, particularly with gelatine,
 which constitutes the greater part of the skin  of animals.
 On account of this  property it is emyloyed in the tanning
 of leather, which circumstance has given rise to  its name.
 The tannin which  is  employed  in the manufacture of
 leather is that which is contained  in the bark  of different
 trees; as  the oak, sumach, dec   Tannin may be  ex-
 tracted from nutgalls, in  which it is combined  with gallic
 acid; obtained according to  the best methods, there will
 still remain a portion of the substance used  in its prepara-
 tion.   M.  Proust  recommends preparing  it  by adding
 chloride of tin (muriate of tin) to an infusion of nutgalls,
 collecting the precipitate, washing  it, diluting in water,
 and passing over it a current of sulphuretted  hydrogen,
 filtering and then evaporating  the liquor.   This  tannin
 will retain a small quantity of muriatic and gallic acids.
  Bouillon-Lagrange says that tannin can absorb oxygen
 and then  becomes gallic acid.   According to Berzelius.
tannin consists of Hydrogen,  .   .    4-186
                Carbon,  .  .   .  51-160
                Oxygen,  .  .   .  44-654
  Tantalates.   See Columbates.
  Tantalum.  A  metal analogous to  columbium;  dis-
 covered by Ekeberg, since proved to be the same as
 Columbium.   (See this word.)
  Tartar.  (Tartre.) In Latin tart arum, from the Greek
 lartaros.  Is deposited on the sides  of casks  during  the
 fermentation of  wines,  forming a  lining  more or  less
 thick, which  is scraped  off.  This  is crude tartar,  and 
T A  R
483
consists of a peculiar acid called tartaric acid, saturated
with the potash employed in purifying the wine ;  it is a
super-tartrate of potash.
  Tartar Cream of.   The popular name of the puri-
fied  super-tartrate of potash.
  Tartar  Emetic.   The tartrate  of potash and anti-
mony.
  Tartar Salt of.   The sub-carbonate of potash.
  Tartar  Soluble.   Neutral tartrate of potash.
   Tartar  Vitriolyted.  Sulphate of potash.
   Tartrates.  Tartaric acid can combine in many pro-
portions with salifiable bases ; the compounds which re-
sult  are remarkable in this respect;  that when soluble in
water they  become less so by the addition of a certain
quantity of acid, and when they are insoluble an  excess
of acid  favours their solubility, as in  the case  of other
salts.  Most of the tartrates are insoluble, or almost so,
except  those  of magnesia, the deutoxide of copper, and
the alkaline tartrates; most of the  strong acids disturb
the solutions of the soluble  neutral tartrates, by uniting
with a portion Of their bases and changing them to acid
tartrates, while they facilitate the solutions of the insoluble
tartrates by making them also pass to the acid state.  For
the same reason tartaric acid forms no precipitate in lime
water, or the water of barytes, dec, or rather it will re-
dissolve that  which  it has formed ; but the same thing
does not take place in a solution of potash or in a con-
centrated solution of soda or ammonia.  It  precipitates
nothing at first, but when the quantity of alkali contained
in the liquid is saturated, it forms a less soluble acid tar-
trate which is deposited in a crystalline  state.  If it is
attempted to obtain a precipitate, by pouring  an alkaline
tartrate into the solution of a salt  whose  oxide  forms an
insoluble tartrate, the effect will not  be produced, owing
to the  great  tendency of the tartrates  to form  double
salts, which salts are almost always insoluble. 
IS4
T  A R
   According to Berzelius, the neutral  tartrates are com-
posed in such a manner, that the  quantity of oxygen of
the base is to the quantity of acid in the proportion of 1
to 8-35; Gay-Lussac and Thenard state this  proportion
as 1 to  12-14.
   Tartrate of Antimony and Potash. Emetic Tartar.
It is a colourless salt, with a .disagreeable metallic taste,
susceptible of crystallizing in tetrahedrons  or elongated
octoedrons.   It effloresces in the  air.  Exposed to  the
action of caloric, it decomposes, giving rise  to  different
volatile  products, and a  residue formed of potash  and  an-
timony reduced by the charcoal of the acid.   When pun
it is soluble in 15 parts of water at the  ordinary tempera-
ture and in double its weight of boiling water.  Sulphuric
acid forms in the solutions of emetic tartar a white pre-
cipitate, solul!o in a great excess of acid, and the hydro-
sulphurets produce with it  a precipitate whose  colour
varies from orange to red brown  according to the quan-
tity of re-agents employed.   This precipitate, dried and
heated in a crucible with the tartrate of potash, produces
antimony in  a metallic state.
   Caustic potash also precipitates the solution of, emetic
tartar ;  this solution is very soluble in an excess of alkali.
Lime water precipitates it abundantly;  the precipitate is
formed  of the tartrate of lime and antimony; the water
of barytes acts in the same manner.  The  alkaline  sul-
phates do not disturb the solution  of emetic tartar, but if
they have an  excess  of acid they  produce  a  milk white
precipitate.   It is precipitated by most decoctions of  ve-
getable  substances, and the  precipitate is always formed
of the oxide  of antimony^ and vegetable matter.  An in-
fusion of nutgalls added to a solution of this tartar, pro-
duces an abundant yellowish white precipitate.   A solu-
tion of albumen or gelatine does not disturb  it.
   The  emetic tartar is obtained  by boiling  a mixture
composed of water and equal parts of tartrate of potash 
T A  R
185
 and glass of antimony; the excess  of the  tartaric  acid
 dissolves the oxide, and a triple salt is obtained by crys-
 tallization.
   According to Thenard, 100 parts of emetic contain
              34 of the tartrate of potash,
              54 of the tartrate of antimony,
               8 of water,
               4 loss.
   This salt is an important article in medicine ; its action
 wpon the animal economy is very energetic.
   Tartrate  of Potash.  (Tartrate  de Potasse.)   A
 colourless salt, of a bitter taste,  susceptible of crystal-
 lizing in four-sided prisms terminated by two faces.   It
 dissolves in its weight of cold water, and in a less quan-
 tity of boiling water ;  it easily passes through the aqueous
 fusion.  Its  concentrated solutions  can dissolve a con-
 siderable proportion of albumen in jelly.  It is precipi-
 tated by all the acids sufficiently strong to take a portion
 of the base.   This salt is used in medicine ; it was for-
 merly called vegetable salt.  It is prepared by saturating
 with potash the excess of acid of the cream of tartar,
 (acid or supertartrate of potash) filtering and evaporating
 the liquor.   The crystals form in a few days.
   Tartrate of  Potash  (Acid.)   Super-Tartrate of
 Potash.   Cream of Tartar.  The grape containing a cer-
tain  quantity of acid tartrate  of potash  and tartrate of
lime, these necessarily exist in the expressed juice or
wine, and fermentation takes place ; the quantity of alco-
hol which is  produced  precipitates  these tartrates, and
with them some salts, a vegetable matter, and  a colour-
ing matter; the latter is more abundant in  red than in
white  wine.   This substance is deposited in  layers;
when collected it is known in commerce by the name of
crude tartar; this when purified is called cream of tar-
tar.   It is a hard white salt, of an acid taste, susceptible
of crystallizing  in quadrangular  prisms with  oblique
                         41* 
186
T  A  R
bases.   They contain T§-7 of  the water  of  crystal-
lization.   Cream of tartar exposed to the action of ca-
loric decomposes, producing a certain quantity of hydro-
tartaric acid.  It dissolves in  15 parts of boiling water,
and in 60 parts of water at the ordinary temperature.  It
is insoluble in alcohol.
  All the bases which can form soluble compounds with
tartaric acid can saturate the excess of acid of cream of
tartar, producing double salts more soluble than the cream
of tartar.  Of the different combinations which this sub-
stance forms with  the other salts and with some  acids,
the most remarkable  is that which  it forms with boracic
acid.   M. Soubeiran  considers the  soluble cream of tar-
tar as a double tartrate, in which the  boracic acid per-
forms the part of a base, and saturates the excess of the
acid of the super-tartrate  of potash.
   Tartrate of Potash  and Iron.  A greenish salt, of
a sharp and  styptic taste, susceptible of crystallizing in
acicular prisms, soluble in water.  Its solution is precipi-
tated  black by sulphuretted hydrogen, and is not precipi-
tated  by the alkalies.   It is obtained by boiling in a suffi-
cient  quantity of water a mixture of cream of tartar and
iron filings ;  the liquor is  filtered and evaporated.   This
was formerly called soluble martial tartar.   Different pre-
parations of  the tartrate  of potash  and iron have long
been  in use in medicine under various names.  The tar-
tarized tincture of  mars  is  only an aqueous  solution of
potash and iron preserved by means of alcohol; by eva-
porating this liquor is obtained  the extract of mars.   The
chalybeated tartar is prepared by mixing 40 parts of acid
tartrate of potash with 160 parts of the tartrate of potash
and  liquid  iron, and evaporating   the mixture  to dry-
ness.  The saline residue is preserved in closely stopped
bottles.
   Tartrate of Potash  and  Soda.  A  colourless salt,
of a  bitter taste, unalterable by the air,  very soluble in 
T  E L
48'
water, and susceptible of crystallizing in large and regu-
lar 6  or 8 sided prisms.  This  salt, which  is known by
the name of Rochelle Salts, is employed in medicine ; it
is obtained by saturating with soda the excess of acid of
the tartrate of potash.
   Tartrate of Soda.   This resembles in many of its
properties the martial tartrate of potash ; it can always
be distinguished by its acicular prisms.  It is prepared by
 a direct process.
   Taetiutes.  See Tartrates.
   Tears.  They  contain  a small portion  of  albumen
 combined with soda, muriate of soda, and water.  Also
 portions of their salts.
   Tellurates.    This term   denotes  the compounds
 formed by the union of the oxide  of tellurium  with  the
 different  alkalies  and metals.   If  we add  a  solution of
 tellurate of potash to solutions of barytes, strontian, lead,
 copper, and  lime, insoluble tellurates of their oxides are
 formed.
   Tellurate of  Potash.  A crystalline white powder,
 scarcely soluble in water.   It may be formed by heating
 the oxide of tellurium with nitrate of potash, and dissolv-
 ing  the  residuum  in boiling water.   When the water
 cools, this substance is deposited.
   Telluretted  Hydrogen.   (Hydrogene Tellure.)  A
 colourless gas, of an odour resembling sulphuretted hy-
 drogen ; it  reddens litmus.  In contact with an  ignited
 .body, it burns with a disengagement  of light and caloric.
 This gas dissolves in water;  its solution is  reddened and
  decomposed by contact with the air, giving place to water
  and  a brown powder, which  seems to be a hydruret of
  tellurium.   This  gas may perhaps  be considered as a me-
  tallic hydracid, for it  possesses the property of uniting
  with salifiable bases.  Telluretted hydrogen is obtained
  by treating  with  water an alloy of potassium and tellu-
  rium ; by the decomposition of water a combination of 
lfS8
T  E M
telluretted hydrogen and potash is formed ;  hydro-chloric
acid is then added ; this disengages the telluretted hy-
drogen  from its combination  by uniting with the base :
the gas is  then collected over the hydrargiro-pneumatic
cistern.  It was discovered by Davy in 1809.
  Tellurium.   A  brilliant metal, of a bluish  white, a
lamellar structure,  so brittle as to be easily reduced to
powder.  Its specific gravity is 6-115;  it fuses  at a mo-
derate temperature ; if heated more, it volatilizes.   Like
potassium and arsenic it forms with hydrogen a gaseous
compound.  It burns with intenseness in  oxygen gas ;
nitric acid dissolves it with a  disengagement of caloric,
and  the solution  forms with  sulphuretted  hydrogen an
orange brown precipitate.   Tellurium has been  found in
nature in a state of alloy with gold, silver, lead, copper,
iron,  and often with  many of these metals  united.  It
was  first discovered by  M. Muller in  the gold mines of
Transylvania.  It is obtained by treating the ore usually
composed of gold, iron, and tellurium, with a quantity of
nitric acid sufficient to dissolve the last two metals.  The
solution is  treated'  by caustic  potash,  which precipitates
the oxide of iron, and to the new liquor is added hydro-
chloric  acid, in order to neutralize the potash.   The tel-
lurium  deposites in the form  of the sub-chloride ; it is
washed with weak alcohol, (as  it would dissolve in water,)
then dried, mixed with a certain quantity of  charcoal, and
the mixture is heated in  a retort.  When tellurium is
found combined with the metals, the process of extract-
ing it must of course vary  with the nature of the alloy.
  Temperature.   A definite  degree of heat is measured
by the thermometer;  thus  we  say a high temperature, a
low temperature, to denote a manifest intensity of heat or
cold ; the temperature of boiling water, or 212°, (equal
to 100° of the centigrade  thermometer,) and a  range of
temperature to designate the intermediate point of heat
between two distant terms of theometric indication. 
T  II  E
489
  Tendons.   Like the  true skin they  are  composed
almost wholly of gelatine—are soluble in boiling water.
  Tests.   See Re-agents.
  Theory Atomistic  See Atom.
  Thermometer.  (From the Greek, therme, heat, and
metron, a  measure.)  An  instrument  for measuring the
degrees of heat.   A thermometer is a hollow tube, her-
metically* sealed, and  blown at one end  in the shape of
a hollow globe.   The bulb and part of the tube are filled
with  mercury, which is   the only  fluid that  expands
equally.   When we immerse the bulb of the thermome-
ter  in  a hot  body, the mercury expands, and of course
rises  in the  tube ; but when  we  plunge it into a cold
body the  mercury contracts, and of course falls in tho
tube.
  The rising of the mercury indicates, therefore, an in-
crease of heat; its falling  a diminution of it;  and the
quantity which it rises or  falls denotes the proportion of
increase  or diminution.   To  facilitate observation, the
tube is divided into a  number of equal parts  called de-
crees.  Further,  if we plunge  a thermometer ever so
often  into  melting snow or ice, it will always stand at the
same  point.  Hence we learn that snoib or ice always be-
o-ins to melt at the same temperature.  If we plunge a
thermometer repeatedly in.o water kept  boiling, we find
that the mercury  rises up to a certain  point.   This  is
therefore  the point at which water always boils, provided
the pressure of the atmosphere be the same.   There are
four different thermometers used at  present in Europe,
differing  from each other in the number of degrees into
which the space between the freezing and boiling points
is divided.  These are Fahrenheit's, Reaumur's, Celsius",
and Dclisle's.

  * To seal hermetically is to close the end of a glass  vessel while it is in a
melted state, the term hermetic being derived from Hermes or Mercury, who
 u as considered the father of chemistry. 
190
T  II O
  The thermometer uniformly used in  Britain and Ame-
rica is Fahrenheit's ;  in this the freezing point is fixed at
32°, the boiling point at 212° above  0, or the part at
which both the ascending  and  descending series com-
mence.   In the thermometer which was first constructed
by Reaumur, the scale is divided into a small number of
degrees upon  the same length, and contains not more
than 80° between  the freezing and boiling point.   The
freezing point  is fixed in his thermometer precisely  at 0;
the term between the ascending  and descending series of
numbers.  Again  100 is the number of the degrees be-
tween the freezing and boiling point in the scale of  Cel-
sius, which has been introduced into  France since the
revolution, under the name of centigrade  thermometer,
(thermometer of a  hundred degrees ;) and the freezing
point  is in this, as in the thermometer of Reaumur, fixed
at 0.   One degree on the scale  of Fahrenheit  appears
from this account to be equal to £ of a  degree on that
of Reaumur, and to f of a degree on that of Celsius.
  The  space  in  Delisle's  thermometer  between  Un-
freezing and boiling points is divided into  150° ; but the
graduation  begins  at the  boiling  point,  and increases
towards the freezing point.  The boiling point is marked
0, the freezing point  150°.  Hence 180 F. = 150 D., or
6 F. = 5 D.   To reduce the degrees  of Delisle's  ther-
mometer under the boiling point to those of Fahrenheit's,
we have F. = 212 -J- 65 D. * Upon the knowledge of this
proportion, it is easy for the student to reduce the  degrees
of any of these thermometers  into the degrees of am
other  of them.
  Thorina.   See Oxide of Thorinium.  The substance
formerly known by this name, has since been ascertained to
be only a phosphate  of  yttria.   Very recently however
Berzelius has discovered a new substance resemblino- this
in its  properties ; hence its name.   Thorina is white and
irreducible by charcoal and potassium after being strongly 
                        T I N                    49]

 calcined ;  it is attacked by none of the acids except con-
 centrated sulphuric, even after being treated with caustic
 alkalies.  The sulphate of thorina is very soluble in cold
 water, and almost  insoluble in boiling water;  so  that it
 may be  freed from other salts by washing 'the mixture
 with boiling water.  Thorina dissolves easily in carbonate
 of ammonia; an  elevation of  temperature occasions a
 precipitation of a part of  the  earth, but  on  cooling the
 precipitate disappears.  All the salts of thorina have a
 pure astringent taste very  similar to that of tannin.  The
 chloride of thorium treated with potassium  is decom-
 posed with  a triple deflagration.   There results a gray
 metallic powder which does not  decompose water, but
 which  raised above a red heat  burns with  a splendour
 almost equal to that of phosphorus in oxygen gas.   Ne-
 vertheless  thorium is feebly attacked by nitric and sul-
 phuric acids.   The  hydro-chloric on  the  contrary dis-
 solves with a brisk effervescence.   Thorina, or the oxide
 of thorium, contains 11-8 of oxygen.   Its specific gravity
is 9-4.    Thorina exists in a new mineral which has been
 found only in very small quantities at Brevig in Norway.*
  Thorinium.  A name given  to  the supposed base of
thorina, now proved to be  a phosphate of  yttria;  it has
 not yet been insulated.
  Thorium.  The  base of the newly discovered sub-
stance, thorina.
  Tin.   (Etain.   In Latin stannum; called Jupiter by
(he alchemists.)   A white, brilliant, malleable metal; its
specific gravity is 7-291.   It fuses at about 412° ;  if the
temperature  is elevated, it inflames  and  oxidates.  It
 combines easily with  phosphorus, sulphur,  chlorine, and
 iodine ;  it also forms many alloys which are employed in
the arts.  Nitric  acid oxidizes  but does not dissolve it.
The solutions of tin form with the alkalies a white  preci-

 * This article is extracted from the first volume of a valuable work on Che-
 mistry recently published by Prof. Silliman. 
492
T  O X
pitate soluble in  an excess of potash or soda;  it is not
precipitated by sulphuretted hydrogen, but the hydro-
sulphates  produce with  it  chestnut-coloured   precipi-
tates if it is  a protoxides, and orange-coloured  precipi-
tates if it is1 a peroxide.   Tin is usually found in naturr
in the state of an oxide ;  the sulphuret is very rare.  Tin
is obtained by roasting the oxide when it contains sul-
phurets or arseniates of  iron.   See Oxide of Tin.
  Tincal.  A name given to native borate of soda. Sec
Borate of Soda.
  Titanium.  A  metal  of a redder  hue than  copper,
infusible, very brittle.  It has yet  been obtained only in
the form of brilliant pellicles.  Its specific gravity is not
known.   It absorbs the oxygen of the air at an elevated
temperature, and passes to the state of a blue oxide which
appears rather to  perforin the part of an  acid than an
oxide.  Titanium is not affected by  nitric acid  ; but its
oxide combines with it,  and produces a solution which is
not precipitated  by sulphuretted  hydrogen,  but  forms a
red brown precipitate with the ferro-cyanate of potassium.
   Titanium was  first  observed by Gregor  in  Cornwall,
England.  It is  found in nature  in  the  state of a gray
oxide ;  it is  often  combined with silex and lime.  The
most pure  form of native titanium is in a mineral  called
rutile, (ruthile,) whose  crystals are often united, and which
almost always contain the oxides of iron and manganese.
The oxide of titanium is extracted from these minerals ;
the pure metal  is obtained from  the  oxide  by mixing it
with  charcoal, making a paste of this mixture with  oil,
and exposing it in a retort to a temperature sufficiently
elevated to reduce it.
   Tombac   White alloy of copper with arsenic.
   Toxicology.   (From the  Greek  toxon, poison, logos,
a discourse.)  A dissertation on  poisons.   The most
celebrated is that of Orfila. 
FRO
493
  Tragacanth (Gum.)  The  substance vulgarly called
gum dragon, exudes from a prickly bush, the Astragalus
tragacantha, which grows wild  in warm climates.  This
gum differs from all other gums  in giving a thick  con-
sistence to a much larger quantity of water ;  it dissolves
but imperfectly.
  Tree of Diana.  (Arbre de  Diane.)  A name given to
elegant crystals of silver with a  little  mercury.  These
are easily obtained by putting  into a decanter  an  amal-
gam prepared with 1  part silver, 6 mercury, 6 parts of
the solution of silver in  nitric  acid, and as much of the
solution of mercury in  the same acid ;  to these are added
40 parts of water, and  in a short time upon the amalgam
will be formed beautiful imitations of the  branches of
trees.
  Tree of Saturn.  (Arbre de Saturn.)  A name given
to metallic  crystallizations analogous to the preceding.
It is formed of 1 part of acetate of lead dissolved in 30
parts of water ; this  solution is put into a decanter, from
the mouth of which is suspended  by the cork  a piece of
zinc of half the weight of the acetate of lead.  The de-
composition now commences, and the  lead crystallizes
iround the piece of zinc  This  establishes an element
of the voltaic pile ; the precipitating metal i-s always posi-
tive, the precipitated metal always negative. From thence
arises the  decomposition of the water, of the  salt which
was dissolved in it, and the reduction of the metal which
it contained.  The crystals of lead shoot out in  every
direction from  the zinc, in an arborescent form.   It is
necessary that the operation should proceed without any
agitation of the liquor.
  Teona.   The sesquicarbonate  of soda.  It is found in
a native state on the banks of  the soda lakes in Africa,
and consists of one atom of soda, an atom and a half of
,tcid, and two atoms of water.
                          42 
494
TUN
   Tubes.  Cylindrical vessels of glass or metals, either
straight or bent, which serve to connect the different parts
of an apparatus.
   Tube of Safety.   A tube open at both ends inserted
into a receiver, the  upper end  communicating with  the
external air, and the lower being immersed in water.  Its
intention is to  prevent injury  from too sudden condensa-
tion or rarefaction  taking place during an operation.  For
if a vacuum be  produced within the vessels, the external
air will enter through the tube  ; and  if air be generated,
the water  will yield to the  pressure, being forced up the
tube.  Thus, too, the height of the water in the tube indi-
cates the degree of  pressure  from the confined gas or
gases.  It is now more frequently used in a curved form,
and is commonly called Welter's tube.
  Tungstates. Although tungstic acid does not possess
acid properties in a very marked degree, yet the tung-
states are with  difficulty decomposed, because their acid
is neither liberated nor volatilized by caloric :  When a
tungstate is submitted  to  the  action of this agent, it de-
composes,  but  at  a temperature sufficiently elevated to
reduce the metal, if the metal is  reducible by heat alone ;
if this is not the case, the tungstate undergoes no altera-
tion.  All are insoluble in water, except  those of potash,
soda, and ammonia.  When a powerful acid, as sulphuric
or nitric acid, is put into a solution of tungstate of potash
or of soda, the  decomposition  is not total at the ordinary
temperature ;   a sulphate, a  nitrate, dsc, is  obtained,
which remains  dissolved in the liquor, and a white preci-
pitate which is  a combination of much tungstic acid, of a
certain quantity of the base to which  it was united, and of
a certain quantity  of the acid employed to separate it.
But if the  acid  is in excess and the temperature elevated,
the decomposition is total after  boiling  a little,  and the
precipitate becomes yellow, which   indicates  that  it is
formed of tungstic acid.  (Thenard.) 
TUN
495
  In nature there have been found but three  tungstates.
The tungstate of iron and manganese (wolfram) is black
and very heavy ; its specific gravity is 7-S.  Its pr: ^ntive
form is a rectangular prism, but often altered by trunca-
tion.
  The tungstate oflime (sceehlite) is white, crystallizes in
octoedrons, often grouped.  Its specific  gravity is 5-5.
The tungstate of lead is very rare ; it has  been found in
Bohemia in a tin mine.   It is yellow or green, a -i crys-
tallizes also in  octoedrons ; its specific gravhy is 8. The
soluble tungstates which  are colourless are obtained di-
rectly ; the others are obtained by  double decomposition.
In these  salts the quantity of oxygen of the oxide is to the
quantity of oxygen of the acid as 1 to 3, and to tne quan-
tity of acid in the proportion of 1 to 15-075.
  Tungstate of Ammonia.   A white salt, crystallizes in
very  fine  4-sided prisms or in micaceous  scales.  Its
taste  is styptic  ; it does not alter by the air, but is  easily
decomposed by heat, and  by many acids.   I; is obtained
directly.
  Tungstate of Potash.   A white deliquescent  salt, of
a caustic and astringent taste, crystallizes with difficulty.
It is obtained by heating an excess of tungstic acid with a
solution of potash.  In preparing it, the wolfram, or tung-
state  of  iron and manganese, is employed ; the latter is
heated with hydro-chloric acid, which dissolves the oxides
of iron and  manganese  without  attacking  the tungstic
 icid, which is  afterwards united to the potash.
  Tungstate of Soda..  A white  salt of  a  sharp and
burning taste,  very soluble in water, and susceptible of
crystallization  in very short hexahedral prisms ; it is ob-
tained like the preceding.
  Tungsten.  (Tungstene.)  (Swed. Tungsten, ponderous
stone.)  A very hard brittle metal,  of a  grayish  white,
brilliant  and almost  infusible.  Its  specific  gravity is
17-6.  At red  heat it absorbs oxygen from  the air, and 
496
U  L M
 becomes brown.  The acids do not sensibly affect it.  Its
 oxide forms no salts either with the acids or the alkalies ;
 but its acid, which is  blue, can unite with the  last and
 neutralize  them.  It  may be  seen by these properties,
 that tungsten seems scarcely to belong to the metals, but
 rather to  deserve a rank with  osmium, and some other
 substances which constitute a link between the non-me-
 tallic combustible  bodies and the  metals.   It has been
 found in  nature, only  in the state of an  acid  combined
 with the oxides of calcium, iron,  manganese,  and lead.
 It is extracted from the tungstic acid, by mixing this with
 charcoal  and  making  a paste with  oil; this  paste is
 heated in a crucible of charcoal, and the acid is reduced.
 The discovers  of tungsten is due to Elhuyart,  though
 Scheele and Bergmann hinted at its existence.
   Turpeth Mineral.  (Turpeth Mineral.)   Ancient
 name for the sub-deulo-sulphate of mercury, on account of
 its yellow  colour,  which was  compared  to that of the
 turbith.
   Tumeric   Curcuma.
   Tuttv.  An impure oxide of zinc
   Turnsol.  See Litmus.

                         V.

   Ulmin.   (Ulmine.)   A solid, inodorous,  insipid  sub-
 stance, of a shining black ;  it  is  insoluble in  cold, and
 very little so in boiling water; it  however gives  to  the
latter a yellow tinge.   Alcohol and sulphuric acid slightly
dissolve it; it reddens litmus ;  with the alkalies it form?
combinations  which are  very  soluble in water, are  de-
composed by acids and by the earthy salts.   The nitrates
of lead and mercury discolour a solution  of ulmin and
precipitate it brown.   This substance was  discovered by
 Vauquelin in  the brown  exudation of the  elm (ulmus).
 Klaproth, Berzelius, and Braconnot have studied this sub- 
V  E N
497
 stance.   Berzelius  believes that it constitutes a part of
 all barks ; Braconnot found it in turf, mould, and in clayey
 lignite.
   Ultramarine.   See Blue.
   Umber.  An ore  of iron.
   Uranium.  A solid metal,  very brilliant, brittle, of  a
 deep gray, specific gravity 9.000.  This metal is scarcely
 softened by the most intense heat.  When heated in the
 air, it absorbs oxygen, and becomes a black oxide.   It is
 very scarce in  nature ;  is found  only in the  state of  a
 phosphate  and a protoxide.  It is obtained like chromium,
 by calcining the oxide strongly  in a crucible, with char-
 coal.  It was  discovered by Klaproth  in a mineral called
 Pech-blende, or oxide of uranium.   Combined  with car-
bonic acid, it forms the Chalcolite or green mica.
   Uret.   {Ure.)  The compounds of simple inflamma-
 ble bodies with each other, and with metals  are  com-
monfy designated by  this word as sulphuret of phosphorus,
carburet  of iron, dec  The terms bi-sulphuret, bi-sul-
phate, die, applied to compounds, imply that they  con-
tain  twice  the quantity of sulphur, sulphuric acid, die.
 existing in the respective  sulphuret, sulphate, dec


                         V.

   \ AuauELiNi;.  When  Pelletier and  Caventon made
the discovery  of strychnine, they  gave it  the name of
Vauqueline, in honour of a celebrated chemist;  but when
the memoir of the  discoverers was read to the French
National Institute, it  was  decided that the name proposed
was  not properly bestowed upon a substance of so  dele-
 terious a nature ; and that  it should be called strychnine
from Strychnos, the plant in which it seemed to be most
abundant.
   Vents.  An ancient name for copper.
                        42* 
498
V  E  R
  Veratria.   (Veratrine.)   A  white  inodorous  sub-
stance, very sharp to  the taste, without any bitterness.
It fuses at 122°, becoming a white  mass like wax ; at a
higher degree of temperature it decomposes, and gives
all the products of vegeto-animal substances.  It is solu-
ble in ether, and alcohol, wholly insoluble in cold water,
boiling water scarcely dissolves T¥Vo Part» >et tnis small
quantity communicates to it  a very sensible sharpness of
taste ; in  a degree,  it  possesses  alkaline  properties,
changes  litmus  paper, reddened by  an acid, blue, and
saturates the acids  with which it forms uncrystallizable
salts.   Concentrated nitric  acid decomposes it  without
giving it  a red colour.  This organic alkali was  disco-
vered by Pelletier and Caventon in  1819, in the seed of
the Veratrum sabatilla orcevadilla, the Veralrurn album or
white hellebore, and the bulbs of the Colchicum autumnale
or meadow saffron.  In obtaining this  substance, the
pounded  seeds of the cevadilla are first treated with sul-
phuric ether, which  dissolves an oily matter, a colouring
matter, and an odorous acid ; the residue is several time:
treated with boiling alcohol, the different solutions bein-
cooled, filtered, and evaporated  to an extractive consist-
ence ; it. is redissolved in cold water ; the aqueous solu-
tion, on being evaporated, deposites a reddish matter; when
the liquor has acquired  a degree of  concentration, it is
precipitated by the acetate of lead,  a current of sulphu-
retted hydrogen precipitates the excess  of  lead,  and a  4
colourless liquid is obtained; this being treated with mag-
nesia, the veratrine  precipitates with the magnesia ; the
veratrine is dissolved by boiling the precipitate in alcohol;
on filtering and cooling, the  veratrine is in part deposited;
the other part is obtained by evaporating the alcoholic
solution.   According to  Pelletier and Dumas, this sub-
-*ance consists of   Carbon  .   66-75
                    Azote   .    5.04
                    Hydrogen    8.54
                    Oxygen .   19.60 
VOL                  499
According to the experiments of Magendie, veratria ex-
ercises upon the  animal economy, the same action as the
cevadilla and the hellebore, but  with much  greater
energy.
  Verdigris.   (Verdet.)   (Vert-de-gris.)   (In Latin,
asrugo.)  An impure acetate of copper ;  being a mixture
of the  acetates and the carbonates of copper, and the hy-
drated oxide of copper ;  by crystallized verdigris is under-
stood the neutral acetate of copper.
  Verditer.  A blue pigment obtained by adding chalk
or whiting to a solution of copper in aquafortis.
   Verjuice.  A kind of harsh sharp vinegar made of thf
expressed juice of the wild or crab apple; also applied to
the sour juice of unripe grapes.
  Vermilion.  The  red sulphuret of mercury, or cinna-
bar.   See Sulphuret of Mercury.
   Verre.   See Glass.
   Vert de Scheele.  See  Green Scheele':-.
   Vif-Argent.   See Mercury.
   Vin.  See Wine.
   Vinegar (Vinaigre.)  See Acetic Acid.
   Vital Air.  See Oxygen.
   Vitreous. (From vitrvm, glass.) Glassy.
   Vitrification.   See Glacs.
   Vitriol Blue.  Sulphate of Copper.
   Vitriol Green.  Sulphate of Iron.
   Vitriol White.   Sulphate  of Zinc.
   Vitriolic Acid.  See Sulphuric Acid.
   Volatile Alkali.   See Ammonia.
   Volatility.   A property of bodies by which they tend
 to assume the vaporous or elastic state.
   Volumes Theory of.  When bodies unite so as to form
 one compound only, that compound always contains the
 same  relative proportions of its components ;  and when
 two bodies unite in more than one proportion, the second.
 third, &c, proportions  are  multiples, or divisors  of thr 
:>00
YV A T
first.   This law is well exhibited in  the combinations of
gaseous bodies.   These are seen to unite in simple ratios
of volume.   Water is composed of hydrogen and oxygen ;
1 part by weight of the former gas unites to 8 of the lat-
ter.   The specific gravity of hydrogen compared with
that of oxygen is  as  1 to 15;  it is obvious therefore that
1 volume of hydrogen unites to half a volume of oxygen.
and that the composition of water will be represented b\
weight and volume, thus :
1 Hydrogen	8 Oxygen
	
  Muriatic acid gas consists of 1 part by weight of hy-
drogen and 36-0 by weight of chlorine. The relative spe-
cific gravities of these gases are as 1 to 36.  It is obvious
therefore that  they combine in equal volumes, and that
muriatic acid gas may be thus represented :
1 Hydrogen	36 Chlorine.
w.
  Wacke.  A mineral substance intermediate  between
clay and basalt.
  Water. (Eau.  In Latin, aqua.)  It is ordinarily found
in the form of a transparent, colourless, inodorous liquid,
capable of dissolving a great variety of substances.  It
is liquid at the common temperature of our climate, but
becomes  solid at 32° ; and assumes a gaseous  form at
212°, occupying a volume 1700 times greater than in the
liquid form ; it returns unaltered to its liquid state at any
degree of heat  intermediate between these two  points.
The process called freezing is in fact the  crystallization
of water  ; its crystals,  usually confused, are  regular 
W A T
501
hexagonal prisms. Water is a bad conductor of the elec-
tric ffuid ;  it strongly refracts light.   It dissolves most of
the gases,  but in variable quantities ; nitrogen is  among
those of which water dissolves the least.   Water can be
charged with a great quantity of oxygen, and  then exhi-
bits peculiar properties.   See Water Oxygenated.
   Water affects substances both simple and compound in
a  very different manner, dissolving many, decomposing
some,  and  having no action on others.  Water is seldom
found  pure in nature ; in order to obtain it in this state, it
must be distilled.  This  substance in a solid form consti-
tutes immense  glaciers upon the summits  of mountains,
and exists in vast quantities in the polar regions.
   The clouds  and  vapours  of the atmosphere are  the
same substance  in a gaseous  form.   When condensed by
cold, it solidifies ; being then heavier  than the air, it falls
in the  form of snow, hail, or  rain.
   Water was long regarded a simple principle ; it is now
known to be a combination  of oxygen and hydrogen, in
the proportion of 88-90 of oxygen, 11-10 of hydrogen  ;
or in  volume of 1  of oxygen and  2  of hydrogen; or
which  is the same thing, of 1 atom  of oxygen and 2 of
hydrogen ;  then one atom of water would  weigh  1125,
the sum of the  1  atom of oxygen  and 2  of hydrogen.
Water is the protoxide of hydrogen ; oxygenated water is
the deutoxide.
   Water  of Barytes.   (Eau  de  Baryte.)  Solution of
barytes, or a salt of  barytes  in distilled water.  It is one
of the  most common re-agents in chemistry; its use is
principally to show the presence of sulphuric acid.
   Water of Crystallization.  Many bodies in crys-
tallizing, retain  a quantity of water, this is termed their
water of crystallization.
   Water  Distilled.   (Eau Distiller.) The purity of
distilled  water  is proved by its having  no action upon
coloured papers, not being precipitated by water of ba. 
502
WAX
rytes, nitrate of silver, the deuto-chloride of mercury, or
oxalic acid.
  Water of Lime.  (Eau de Chaux.) This is a solution
of lime  in  water.  Water  saturated by  lime contains
but Ti„-  part. It is much used as a re-agent, to show the
presence of carbonic acid, oxalic acid, die.
  Water  Mineral.  (Eau Minerale)   The waters of
some springs, are impregnated with a certain quantity of
saline substances, and  are thus  enabled to act upon the
animal economy ; they are very useful as medicines.
   Water Oxygenated.  (Eau  Oxigenee.)  This is the
deutoxide of hydrogen ;  it was discovered and carefully
investigated by  Thenard.   It is obtained by dissolving the
deutoxide of barium in liquid muriatic acid, pouring into
the solution  a certain quantity of sulphuric acid, adding
sulphate of  silver, then  barvtes,  and separating suc-
cessively all tin* precipitates  by filtering.   When wateris
most  highly oxygenized, it seems to consist of equal
volumes, making 2 atoms of oxygen for 1 atom of hydro-
gen.
  It is a colourless liquid, of a peculiar taste, susceptible
of vaporizing without being decomposed.   It destroys the
colour of litmus; congeals  at some degrees  below the
freezing point  of water.  Its  density is  1-452.  The
metals generally  decompose it, reducing it  to the  state
of  a protoxide.  Iron, tin,  and  a  few others  are  ex-
ceptions.
  Water of Life.   (Eau de Vie.)   Alcohol.
  Water  of the Sea.   (Eau  de  Mer.)  Sea water,
besides  a great  quantity of common salt, (chloride of
sodium,) contains small portions  of muriates of lime and
magnesia, also  sulphates  of these two bases, and perhaps
a little carbonic acid.
  Wax.  (Cire.)  Is solid, white, insipid, and inodorous  ;
it melts at 154"1, dissolves in warm ether and alcohol, and
precipitates when cold.   The essential and fixed oils dis - 
W O 0
503
■solve it in all proportions.   Wax is  a substance exten-
sively diffused in nature ; it is found on the  surface of
the leaves of vegetables,  in  the pollen  of flowers, and
many trees produce  it abundantly.   Since wax is so ex-
tensively diffused, it would seem as if that which is ob-
tained from bees, is not formed  by these insects,  but is a
product of nature.   M. Huber,  however, says that bees
which feed upon sugar, produce wax in as  great a quan-
tity  as  those whose  food might seem to contain  this
substance.
   Wink.   (Vin.  In Latin Vinum.)  The general term
vinous is applied to all liquors which have been subjected
to the spirkous fermentation (see Fermentation); as  beer,
cider, metheglin.  The term wine (vin) is chiefly limited
to the fermented juice of >he grape.   Although all su-
gared substances can furnish an alcoholic liquor, all do
not produce that which is equally good.   Such wines as
are  richest in alcohol and  aroma, are  called generous
wines (vins genereux).   Wines may be divided into  three
principal  kinds : the  red  wines, (vins rouges,)  as  port,
claret, die ;  the white wines, (vins blanches,) as Madeira,
dtc ; and the sparkling toines, (vins mousseux,) as Cham-
paigne, &c
   Wollastox's  Theory of Crystallization.   Doctor
Wollaston first  suggested that the  form of the integral
molecules of crystals might be  perfect spheres,  and he
has shown that by joining these together, a  number of
crystals  may be obtained, as the octoedron, the tetrae-
dron, the  acute-rhomboid, and even the cube.
   Wood.   (Bois.)   The  liqueous  or  woody  tissure,
which contains between its fibres or in  its vessels the sap,
proximate  principles,  colouring  matter,  dec  Wood
separated from these substances, and  reduced to vege-
table fibre, takes chemically the name of woody fibre.
(ligneuv.)   (See this word.) 
504                     V  E S
    All wood contains at least 0.950 of this fibre in 100 parts ■
  ihere are           Carbon   52
                    Oxygen   48, and hydrogen in neces.
  sary proportions to form water
    Wood calcined  in a  particular  manner, produces  the
  charcoal sought for use in many chemical  experiments.
  The calcining of wood in the large way in order to pro-
  duce charcoal for  domestic purposes, and for  use in  the
  arts, is carried on in what are called coal kilns.
    Woody Fihre.   (Ligneux.)   A solid body of a  dirty
  white, of a specific gravity  greater  than water.   Sub-
  mitted to distillation  in a retort, it  gives similar products
  to vegetable substances.   It is little soluble in potash ;
  when treated by sulphuric acid, it  forms an acid which
  Braconnot calls vegeto-sulphuric acid, and which Thenard
  considers as hydro-sulphurous acid, united to a vegetable
  substance.
   The ligneux is abundant in vegetables, in the  flowers,
 fruit, leaves, roots, and  stems.   It constitutes T9^ of all
 wood in general; it is produced in its most pure state,  by
 treating sawdust successively with water, alcohol,  mu-
 riatic acid, and a weak solution  of potash.
   Wool Philosophic   (Laine  Philosophique.)   Name
 given by ancient che?nists to the sublimed oxide of zinc.


                          X.

   Xanthogexe.   See Acid Xanthie.


                          Y.

   Yest.    (Ferment.)   A viscous  flosculous   matter
which  separates from vegetables when submitted to fer-
mentation.   That which is produced from the fermenta-
tion of beer, is chiefly used in domestic economy, and  is 
Z E T
505
vulgarly called emptings, or emptyings.  It may be dried,
and in this situation preserved for an indefinite  period.
In contact with oxygen at a temperature somewhat ele-
vated, it decomposes, transforming itself to carbonic acid ;
if at the  same temperature it is left to  stand for some
time in close vessels, it putrifies in a few days.   It  dis-
solves neither in water nor alcohol.  If submitted to dis-
tillation,  all the products of animal substances are ob-
tained.   See Fermentation.
  Yellow King's.  Much used in  dyeing.  It  is  pre-
pared from Orpiment.
  Yellow of Naples. (Jaune de Naples.) Patent yellow.
It is employed  in  oil  painting ;  it  is a chloride of lead,
prepared by mixing 200 parts of litharge with 5 parts  of
common  salt, and  4 times their  weight of water.  This
paste swells, takes consistence, and becomes white ;  two
or three days afterwards, it is lixiviated in order to sepa-
rate the soda, and the residue,  which is of a beautiful
yellow colour, is melted.  This paste is sometimes called
 Mineral Yellow.
  Yttria.  See Oxide of Yttrium.
  Yttrium.  This metal  has never been obtained; its
existence  is admitted by analogy.
  Yttro-Cerite.   A mineral containing  oxide  of ce-
rium, yttrium, &c
  Yttro-Tantalite.   An ore of tantalum, from which
'•olumbic acid is procured,


                          z.

  Zaffre.  (Saffrc.)  The residuum of cobalt after the
sulphur, arsenic, and other volatile matters of this mi-
neral, have been expelled by calcination.
  Zeine.   A yellow substance having the appearance of
Wax, obtained from indian corn,  (Zea Mays).
                          43 
506
Z I R
   Zinome.  See Gluten.
   Zinc   (From  a German word  Zincum.)   A  solid
 bluish white metal, little ductile, somewhat malleable, and
 of a lamellar structure.  When heated without being ex-
 posed to the air, it fuses below red heat, and volatilizes
 entirely;  if heated in the air, it absorbs oxygen rapidly,
 solidifies, and produces a beautiful flame of a brilliant
 greenish blue colour.   The metal passes to the  state of a
 white oxide, which on account of its lightness,  rises into.
 the atmosphere.   Phosphorus and sulphur unite with this
 metal, producing a phosphuret and a sulphuret; the first
 is brilliant,  and has a metallic appearance ;  the second
 appears tarnished, and is less fusible than zinc   Boron,
 carbon, hydrogen, and nitrogen, have no action upon this
 metal.  Zinc, like iron, decomposes water by the aid of
 heat, absorbs oxygen, and liberates hydrogen ;  at a high
 temperature it absorbs the oxygen from phosphoric acid ;
 it decomposes  concentrated sulphuric acid  disengaging
 sulphurous acid, and  the oxidated metal combines with
 the portion of acid not decomposed ;  but when the sul-
 phuric acid is feeble, it oxidates at the expense of the
 oxygen of the water, and the acid  undergoes no decom-
 position.  Concentrated  ammonia acts strongly  upon
 zinc ; the water of the former is decomposed ; its oxygen
 burns the  metal, its hydrogen  is  disengaged,  and  fur-
 nishes little acicular crystals, from which  ammonia may-
 be disengaged by heat. Zinc has never yet been obtained
 pure  in a metallic  state;  it is always from calamine that
 the metal is extracted. Zinc is employed in making brass,
 in the construction of voltaic piles, 6ic.  Attempts  have
been  made to  employ it in  the manufacture  of kitchen
utensils; but it is discovered to be too easily attacked by-
acids and fat substances ; its use has therefore  been re-
linquished.
  Zirconia.   See Oxide of Zirconium. 
Z  I R
50?
  Zirconium.   It  has been  known but a  short time.
Berzelius succeeded in separating it from oxygen, with
which  it constitutes zirconia.   It does  not appear  to
possess the properties of metals. According to Berzelius,
it is black, like charcoal ;  it oxidates neither in  the air,
water,  or in muriatic acid ; but dissolves in aqua regia
and fluoric acid, with a disengagement of hydrogen.  It
burns with intenseness at a temperature a little elevated.
It combines with sulphur, and forms a chestnut brown sul-
phuret,  like that  of silicium ;  this sulphuret  does  not
dissolve in muriatic acid  and in the alkalies, which it
burns  with a disengagement of  caloric and light, pro-
ducing sulphurous  acid  and  zirconia.   Berzelius  ob-
tained zirconium in the same manner as silicium. 
 
SKETCH
                     OF

ELEMENTARY  CHEMISTRY.
                    GERERAL VIEW.

   Chemistry is a science no less elevated in its general
v iews than various in its applications ;  its object is to exa-
mine the elements ox first principles of substances and their
laws of combination ; its application to other sciences, to
arts, medicine, manufactures, and housewifery, are nu-
merous and important.  It may be  divided into organic
and inorganic chemistry.
   Organic chemistry is confined to the investigation of the
elements  of vegetable  and  animal substances, and the
laws which govern their combinations. This department,
including the whole of animal and vegetable poisons, and
their antidotes, is intimately connected with the study of
medicine.  The same elements, differently proportioned
and combined, constitute all organic and inorganic sub-
stances.
   Inorganic chemistry includes the study of the elements
of all   matter  confined to  the combinations of  these
elements in inorganic bodies.  The ancients conceived
                        43* 
510
that there were but four elements, or first principles, viz
Earth, air,fire, and water.   Chemistry has shown that all
these substances, except fire, (the nature of which is still
doubtful,) are compounds : air of two gases, called oxygen
and nitrogen; water of oxygen  and hydrogen; and earth
of a variety of substances, which in their turn may be
decomposed.
   Sir Humphrey Davy beautifully observes, that,
  " The forms and appearances of the  beings and substances
of the external  world, are almost infinitely various,  and in o
state of continual  alteration.
  " The whole surface of the earth undergoes  modifications :
acted on by moisture and air, it affords  the food of plants ; an
immense number of vegetable productions  arise from appa-
rently the same  materials; these become  the substance of
animals;  one  species of animal  matter is converted into
another;  the most perfect  and beautiful  forms of organized
life ultimately decay, and are resolved into inorganic aggre-
gates, and the  same  elementary substances  differently ar-
ranged, are  contained in the inert soil,  or bloom  and  emit
fragrance  in the flower, or become in animals the active
organs of mind and intelligence.  In  artificial operations,
changes of the  same kind occur; substances having the cha-
racters of earth, are converted-into metals ; clays and sand arc
united so as to produce porcelain; earths and alkalies are con-
verted  into  glass; acrid and corrosive  matters are  fonned
from  tastless  substances ; colours are fixed  upon stuffs, or
changed, and made to disappear; and  the productions of the
mineral, vegetable, and animal  kingdoms  are converted into
new forms, and made subservient to purposes of civilized life
To trace in  detail these diversified  and complicated pheno-
mena,  to arrange them,  and deduce general laws from their
analogies, is the business of chemistry."

   Nature offers  substances in four different states, solid,
liquid, gaseous or aeriform,  and imponderable, or  such 
                         511
agents as are  not known to  possess weight.   All matter
is composed of molecules, particles, or atoms, which are
subject to two opposing laws, the force of attraction which
tends to  keep the atoms in  contact, and that of caloric,
or heat, which separates or repels them.
   Simple substances are those whose atoms  are  homo-
geneous, or of the  same nature.  Thus zinc is con-
sidered as a simple substance, because it. contains no other
atoms than those of zinc.
   Compound substances are such as contain two or more
simple elements ;  thus brass is a compound body, which
on being decomposed, is  found to contain atoms of zinc
and  copper.   The  particles which constitute a simple
body, are called integrant molecules, and the force which
keeps them together, is called cohesion.   The particles
which form a compound substance, are called constituent
molecules,  and the force  which unites them, is termed
affinity.   Thus zinc is formed of integrant  molecules,
united by the  force of cohesion, and brass is formed of
constituent molecules,  united by the force of affinity.

                      AFFINITY.
   Affinity  is  that kind of  attraction which  unites the
heterogeneous molecules, or atoms of compound bodies,
A knowledge  of  chemical affinity is very important in
investigating chemical changes; the first  consequence of
this  law  is a  change  of state of the  bodies; thus the
union  of two gases,  oxygen and  hydrogen, produces
water.  A second and important consequence is a change
of the property of the  new substance;  thus from the 
512
 combination of an acid and an alkali possessing opposite-
 properties, results a salt resembling neither of the original
 substances.  It is at present  believed by most chemists,
 that chemical affinity depends essentially upon the elec-
 trical  state of  the  substances, that electricity is divided
 into two fluids; the one positive, the other negative, and
 (hat molecules  of the same  kind of electricity repulse,
 while those of opposite electricities attract each other.

                  THHORY  OF ATOMS.
   By atoms or particles are understood parts incapable of
 division or diminution; much precision  is given to the
 science of chemistry by admitting that bodies consist of
 atoms which unite in certain  proportions ; thus in water
 we suppose 2 atoms  of hydrogen united to 1 of oxygen ;
 or, which is the same thing, 200 atoms of the former  to
 100 of the latter.  The theory of the proportions between
 the elements of bodies is not hypothetical, but in many
 eases has been  proved by experiment; thus the following
proportions are uniformly observed :
200 atoms of hydrogen  and 100 of oxygen = water.
300          do.    and 100   nitrogen = ammoniacal gas.
 100        ammonia  and  50   carbon =c salt of ammonia.
 100        nitrogen   and  50   oxygen = protoxide of nitrogen.
'0°          do-    and 100    do.   = deutoxide of nitrogen
100          do.     and 150    do.   = nitrous acid.
 ' °°          do.     and 250    do.   — nitric acid.

                  SIMPLE  ELEMENTS.
   The number  of simple  elements admitted by chemists
 varies with the  progress of the science ;  such substances
 as no chemical force can decompose are called simple ; 
                         513
 many which are thus named, will no doubt, in orocess of
 time be decomposed, while other elements, now unknown,
 will be brought to light, and found to be important agents
 in chemical changes.
   Instead of the four elements  of the ancients,  chemists
 at present admit more than 50 elementary bodies, if we
 include the imponderable agents, chlorine, and some other
 analogous substances; and the  newly discovered bodies,
 bromine, pluranium-, and thorium.
   These may be comprehended  under two grand divisions:
   I.  Imponderable agents, or such  as have  no known
 weight;  as            Caloric,
                      Light,
                      Electricity,
                      Magnetism.
   II. Ponderable bodies, or such as have known weight ;
 these may be divided into four classes.
   Class 1.  Supporters of Combustion; as oxygen, die
   Class 2.  Combustibles not metallic; as hydrogen, dzc
   Class 3.  Metalloids; as silicon the base of silex, cal-
 cium of lime, die
   Class 4.  Metals,

              LANGUAGE  OF CHEMISTRY.
  Among the most important chemical agents is  oxygen,
the discovery of which wholly changed the aspect of the
science, and gave  rise to our present nomenclature, or
names of substances.   The  term combustible, considered
;is synonymous  with oxygenable, is applied to all simple 
514
substances which can be made to unite with oxygen ; this
union is  accompanied with  a disengagement  of caloric
or heat, (though in some cases imperceptible,) and often
of light;  the substance which has thus united with oxygen
is said to  be burnt, or oxygenated.
  The compounds which result from the union of oxygen
with simple bodies have  received the name of  oxides and
acids.  When oxygen unites with a body but in one pro-
portion, forming either an oxide or an acid, the substance
with which it  combines is termed its radical; as in the
oxide of  zinc, here zinc  is the radical,  or base of the
oxide. If the oxygen combines in two or three propor-
tions, the first  oxide  is c ailed protoxide, the second deut-
oxide, the third tritoxide ; when a body is oxidized in the
highest degree it is termed the peroxide ; as for example,
the combinations of  oxygen and manganese which  pre-
sent us with all these varieties of oxides.
   A similar rule governs with respect to the  names of
acids ; if the oxygen forms but  one acid, to its radical is
added the termination ic, as boracic acid.   But if oxygen
combines in several proportions, the  lowest proportion is
expressed by  ous, and the highest  by ic, as  sulphurous
and sulphuric acids;  to these terminations are  also added
hyper, which  signifies more, and hypo, less ;  thus hypo-
sulphurous acid denotes a body possessing a less quantity
of oxygen than sulphurous acid, die
   Oxygen is not the only agent which unites to combus-
tible  bodies to produce  acida;  hydrogen, chlorine, with
?ome other  substances,  possess this property; thus we 
                          515
iiavc hydro-chloric,  and hydriodic acids, resulting from
the union of hydrogen with chlorine and iodine.
   When  two binary* burnt substances combine,  a new
compound  results,  which, when the constituents are an
acid and a metallic oxide, is called a salt.  The salts are
very numerous; they are named  by varying the termi-
nation of their acid, when the acid terminates in ous and
ic, the salt  ends in ite and ate ,- thus by the term sulphate
of tin, we understand the combination of tin with sulphuric
acid;  sulphite of tin expresses  the combination  of the
metal with  sulphurous acid.f

                IMPONDERABLE AGENTS.
   Caloric  and  Light.   It would not  be possible to ex-
plain the sensation of heat to one who had  never expe-
rienced it, any more than we would by words, give to the
blind an idea of colours, or  to the  deaf of  sounds.  A
person says  J am warm, or  extending his hand to a fire,
sayTs  the  fire is hot; in the first case he properly ex-
presses the the sensation of heat; in the second, the cause
of this  sensation.   The  fire itself is  not  supposed to  be
hot,  but only to  possess  the  property of producing in the
animal  system the sensation of heat.  The cause of heal
is  distinguished from heathy the term caloric.
   Light, as is well known, proceeds from the sun  and the
fixed stars, as direct sources;  from the  moon and other
 * The term binary, is derived  from bis, two; a binary compound is one in
which but two elements are united; a ternary compound consists of three e!c
ments; a quaternary, four, &c.
 t For further illustration of the chemical names of salts, see article Women
clature Chemical. 
 planets, by reflection, and from  various terrestrial sub-
 stances,  while  experiencing  combustion from phospho-
 rescent matter, die   The  nature of light and caloric is
 at  present  unknown;  from the  intimate   connection
 between them, they have by some been considered only
 as modifications of the same substance.
   Among the most important properties of caloric, are
   1. Its tendency to an  equilibrium.
   2. Its power of dilating bodies.
   3. Its  susceptibility of being reflected from one bodv
 to another.
   4. Its power of increasing chemical action.
   Electricity and  Magnf.tism.  From whence  arises
 the peculiar sensation which is experienced when a piece
 of zinc placed upon the tongue, is brought in contact with
 a piece of copper placed under this organ ?  What  power
 was that which, under the eyes of Galvani, animated the
 limbs of a dead frog,  when two metals, placed at the ex-
 tremity of a naked nerve, were made to  communicate by
 means of a metallic wire?  What  dazzling brilliancy
 flashes  in the  skies, or darts downwards upon  earth,
 fraught with terror and destruction ? It is the electric fluid.
 But what is the nature of this fluid which divides the ma-
 terial world into  two great masses,  the positively and
 negatively electrified ?  Is it simple or  compound ?  Why
 is its presence  so uniformly accompanied with light and
 heat ?  Are light and caloric any thing more than modifi-
 cations of this fluid, and is not electricity  indeed the union
of these two substances'? 
517
   Electricity, whatever it may be in itself, exercises an
important influence in chemical changes.  The  instru-
ment called the voltaic pile, causes the decomposition of
a compound body, which is submitted to its action;  the
elements possessing  the positive electricity, go  to the ne-
gative pole,* and those which have the negative electricity.,
go to the positive pole of the pile.
   The  magnetic fluid gives  to a mineral called the load-
stone (deutoxide of iron) the'iproperty of directing its two
extremities, either to the north or south pole of the earth ;
of attracting by its northern  extremity the southern ex-
tremity of  another magnet, while it repels its northern
extremity, or pole.   It has recently been discovered that
the magnetic needle  changes its direction under the  in-
fluence of the  voltaic pile;  that the conducting wires
communicate magnetic properties to steel and iron wires.
It has therefore been conjectured that magnetic attraction
is but  another modification of electricity.  If these sug-
gestions are rational, we may perhaps regard  all the im-
ponderable agents as the result of one grand agent.

                PONDERABLE SUBSTANCES.
            Class I.  Supporters of Combustion.
   All  substances upon the  globe except those  already
 described under the head of imponderables, are known to
 possess weight;  the specific gravity even of the lightest
 o-ases  have been ascertained.  After the discovery  of
   * The two extremities of a voltaic battery, are called poles; this instrument
 was first called the Galvanic battery, from Galvani; afterwards, on being mo-
 llified by Volta, it received its present name.
44 
518
oxygen, this gas was  for some time considered as the
only supporter of combustion, or  the  only substance
which by uniting with others, could produce the pheno-
mena of combustion.   At present four other analogous
substances   are   ranked with  oxygen, viz.   chlorine.
iodine, fluorine, and bromine.  When any one  of these
substances, existing in a binary compound, is submitted to
the action of the voltaic pile,  the supporter of combustion
goes to the positive, and the  combustible to the  negative
pole.
  1.  Oxygen unites with almost all substances, forming
acid and oxide compounds; its name is derived  from the
Greek, and signifies to generate oxides; these and most
of the acids being under the  influence of this agent.   Its
properties  are  very numerous, since its   combinations
exist in most bodies in the three kingdoms of nature.   It
has been observed by a celebrated chemist,  that  " oxygen
may  be considered  as the  central point around which che-
mistry revolves."
  The phenomena of combustion  bear  an  intimate rela-
tion to oxygen; so that the slightest union of this gas
with another substance,  although neither  accompanied
with sensible heat  or light, is considered as  a low degree
of combustion.   Stahl supposed that the fire exhibited in
combustion was occasioned by the loss of an imaginary
substance,  which he termed phlogiston, or the  principle
of heat.  Lavoisier proved the materiality of oxygen, by
showing that  it was absorbed by the burnt substance ;
but neither of them accounted for the heat produced at 
                         519
the moment of combustion, nor for the luminous appear-
ance or flame which accompanied it.
   By observing the usual circumstances  of kindling a
fire, we perceive that the temperature of the combustible
body  is first increased by a borrowed  heat; now it is
known that electricity  is developed by an increase of
heat,  and that a union of the two electric  fluids causes
an elevation of temperature; thus, when the caloric is
first added, the two electricities  are  brought forth,  the
negative from the oxygen and the positive from the com-
bustible substance,  and  the union of these two electrici-
ties is supposed to produce the heat which attends com-
bustion.   When we assist combustion  by the  action of
the bellows, we direct a current of air upon the combusti-
ble substance ; the oxygen  being impelled upon its  sur-
face, the fire becomes  more intense ; by repeating the
action of the bellows we successively elevate the tem-
perature, until the  combination of the two electricities is
sufficiently energetic to give rise to flame.   The impor-
tance of oxygen as a supporter of combustion is manifest-
 ed by various  experiments ; even metals inflame  and
 burn spontaneously in this gas.
   2.  Chlorine was formerly  called  oxymuriatic  acid,
 from its supposed constituents, oxygen and muriatic acid.
 It is at present, by the French and most English chemists,
 regarded  as a simple  substance; and muriatic acid is
 now  called hydro-chloric acid,  being  as is supposed a
 combination of hydrogen and chlorine.  Chlorine may be
 obtained by heating the  pulverized per-oxide of manga- 
                          520
 nese with diluted hydro-chloric acid (muriatic acid) ; the
 hydrogen of the latter uniting with the oxygen  furnished
 by the manganese, disengages its chlorine in the form of
 a yellowish green  gas.   Chlorine forms  with oxygen
 several  acids, as chloric, oxygenated chloric, &c.  Its
 union with metals produces chlorides ;  these dissolved in
 water are hydro-chlorates.
   3.  Iodine,  at  the common temperature,  exists in  a
 *olid  form ; its colour  is a bluish gray;  by  heat  it  be-
 comes a violet-coloured gas ;  it forms with oxygen iodic
 acid,  and with  hydrogen  hydriodic acid; combined with
 sulphur, phosphorus, and metals, it forms iodides.  Iodine
 is obtained from sea-weeds, mineral waters, minerals, and
 sponge.
  4. Fluorine is considered as the base of fluoric acid, bin
 as its actual existence has not been proved,  it  must be
 regarded in the light of an imaginary substance.  Whc-
ther fluoric acid consists of  oxygen united to the com-
bustible  base  fluorine,  or whether, as  is supposed  bv
^ome, this base is united to hydrogen, hence the term hydro-
fluoric, instead of fluoric acid,  seems not yet  determined.
This acid united to lime constitutes the fluate oflime, or
the beautiful Derbyshire spar; with other bases it forms
various fluates.
  5. Bromine, which has been  recently discovered and
added to the list  of simple substances, is obtained from
sea-water and  the ashes of the  same marine plants that
furnish  iodine ; it is a dark red liquid,  so volatile as at
the common temperature to throw off red vapours ; with 
521
oxygen it  forms bromic acid, which uniting with various-
bases forms bromates and bromides.
               COMBUSTIBLE  SUBSTANCES.
   Combustible substances are such as possess the pro-
perty of uniting with oxygen and other supporters of com-
bustion to  form oxides  and acids; they may be divided
into the following classes :
            Combustibles not metallic.
            Metalloids, (resembling metals.)
            Metals.
               PONDERABLE SUBSTANCES.
          Class 2.  Combustibles not Metallic.
   1. Hydrogen is a term derived from the Greek, signi-
fying to produce water,  because this liquid is formed  by
(he combination of hydrogen with oxygen ; in the lan-
guage  of chemistry water is the protoxide of hydrogen.
(or hydrogen with one proportion of oxygen); when an-
other proportion of oxygen is added, it  becomes a deut-
oxide of hydrogen, or oxygenated water.  Hydrogen com-
bined with  oxygen and  carbon exists  in  all vegetable
matter ; by  the addition of nitrogen we have the con-
stituents of animal substances.  Hydrogen  forms acids
known by the general name of hydracids;  with chlorine
it forms hydro-chloric, with iodine hydriodic acids, die ;
with sulphur, carbon,  die, it forms sulphuretted hydro-
gen  or  hydro-sulphuric  acid,  carburetted  hydrogen.
\c   It  is  highly combustible, and burns with  much
llame,  furnishing by its union with carbon  the gas used
                         44* 
522
in cities for  lighting streets, shops, «Vc.   On account of
its being specifically lighter than  atmospheric  air, it is
used for inflating balloons.
  2. Boron combined with oxygen constitutes the base
of boracic acid; it  is  by the decomposition of this acid
that boron is obtained, it being never found  pure in na-
ture.
  3. Carbon,  when  perfectly pure  and  crystallized,
constitutes the diamond ; it exists in charcoal with hydro-
gen, salts, and other products of combustion, and may be
obtained from this combination.   Many  attempts  have
been made to crystallize carbon, in order  to obtain dia-
monds, but hitherto none have been successful.   With a
certain proportion of oxygen, carbon forms carbonic acid ;
with a less proportion of oxygen, the oxide of carbon, or
carbonic oxide gas.   Carbon forms with  hydrogen car-
buretted hydrogen, or gas light;  with the alkalies it forms
carbonates, as carbonate of lime, (marble,) carbonate of
soda, die  A peculiar property of carbon is that of ab-
sorbing putrid miasmata, or gases ; a knowledge of this
fact has given rise to some important applications to culi-
nary operations, medicine,  die
   4. Phosphorus  has received its  name from two Greek
words,  signifying  to  bring light,  this  substance  being
always  luminous  in the air.  With oxygen in different
proportions  it forms  phosphoric acid, phosphorous acid,
hypo-phosphorous  acid, and oxide of phosphorus.   With
hydrogen it forms phosphuretted  hydrogen, which  in-
flames  spontaneously in the air, producing  the  exhala- 
                          523
tions, or ignes fatui, which appear about burying places
and marshes.   Bones and other animal substances when
decomposing disengage oxygen, phosphorus, and hydro-
gen ; these united form phosphuretted hydrogen, which
being  specifically lighter than the  atmosphere  ascends,
and by its spontaneous  combustion produces those lumi-
nous vapours which the superstitious and  ignorant  have
referred to supernatural causes.
   5. Sulphur united to oxygen forms sulphuric  and  sul-
phurous acids; these acids united zo bases form sulphates
and sulphites.  With hydrogen sulphur forms sulphuretted
hydrogen, and with the metals various sulphurets, as  sul-
phuret of lead, die
  6. Selenium is less known than any of the non-metal-
lic combustibles ;  it forms with oxygen selenic and  sele-
nious acids and the oxide of selenium.   Selenious acid
forms with bases salts called selenites; selenic acid forms
salts called seleniates.
  7. Nitrogen *  when first  discovered was called azote.
which signifies a  depriver of life ;  this term  appearing
objectionable, as it is not a direct  destroyer of  life,  that
of nitrogen has been given from the  circumstance of its
being an essential ingredient in nitric  acid.   Nitrogen
combines  with oxygen  in   five  different  proportions.
forming

  * In giving nitrogen a place among combustibles, it must be understood thai
it is not combustible in the common acceptation of the term, as it does not take fin
upon being brought in contact with a burning substance, but it is combustible in
the chemical sense of the term, since it unites with oxygen and other supporters
of combustion. 
                         524
               Protoxide of Nitrogen,
               Deutoxide of Nitrogen,
               Hypo-Nitrous Acid,
               Nitrous Acid,
               Nitric Acid.
 With hydrogen it forms ammonia,  with  carbon cyanogen,
 with chlorine  and iodine a chloride and an iodide.   The
 compound substance cyanogen (signifying by its name the
 generator of blue)  is the base  of prussic acid,  (hydro-
 cyanic acid,) which uniting to iron  forms the colour called
 prussian blue.

               TONDERABLE SUBSTANCES.
 Glass 3.   The Metalloids, or Earthy and Alkaline Combus-
                        tibles.
  The termination oids is from the Greek and signifies
 like, or  similar;  thus  the  term metalloids  denotes like
metals.   The substances comprehended in this class are
in the strictest sense  metals,  but  they  differ  from other
metals in their strong affinity for oxygen,  which renders
it extremely difficult either to  obtain or  preserve them  in
a state of purity.   It is but recently that they have been
known to exist;  potash, soda,  lime, die, were considered
as pure alkalies, until Davy, by means of the  voltaic pile.
decomposed potash, and obtained a metal and oxygen :
the  metal he  called potassium; thus it was  discovered
that potash is not an elementary substance, but an oxid<
of potassium.  Reasoning from analogy, Davy and some
of the French chemists were led to believe that  soda.
lime, and other alkaline substances, had metallic  bases. 
525
a series  of brilliant and convincing experiments have
now established this fact.  Metals  of this class  seem
naturally divided into two sections :
  Section 1.  Earthy metals,  or metals which  are  the
bases of earths ; these are,
            Silicon, the metal of Silex,
Zirconium, ,,	Zirconia.
Aluminum, ,,	Alumine.
Yttrium, „	Yttria,
Thorium, ,,	Thorina,
Glucinum, ,,	Glucina,
Magnesium, ,,	Magnesia.
Section 2. Alkaline metals.	
Calcium, the metal of Lime,	
Strontium, „	Strontian-
Barium, „	Barytes,
Sodium, ,,	Soda,
Potassium, ,,	Potash.
Lithium, ,,	Lithia,
                   Class 4.  Metals.
  This class contains substances which have in general
less  affinity  for oxygen than  the  metalloids; many of
them, such as silver and gold, cannot be easily oxidated ;
iron unites  much  more readily with oxygen,  as may
easily be perceived by exposing any  iron vessel to the
action of the  atmosphere ; in a short time  it will be found
rusted, according to the common term, but  which che-
mically is said to be oxidated, the metal having combined 
52G
with oxygen from the atmosphere.    Any article of gold
or silver is not thus  acted upon by the atmosphere, nor
even by water, which iron soon decomposes, by uniting
with its oxygen.
  We  find then  in examining the classification of ele-
ments or simple  substances,
       Imponderable  bodies,.....4
       Supporters of combustion,  ....    5
       Combustibles not metallic,    ...    7
       Metals, including metalloids, about   .   40!

                 BINARY COMPOUNDS.
  Binary compounds (from bis,  two) are such as arc
formed by the  union of two simple substances;  these
compounds are of three kinds ;  1st, those which are nei-
ther oxides nor acids ; 2d, oxides ;  and 3d, acids.
  The binary compounds which possess neither the pro-
perties of acids or oxides are to be found in the union of
the simple combustibles  among their own class ; as car-
buretted  hydrogen, consisting of carbon and hydrogen :
cyanogen, of carbon  and  nitrogen ;  chloro-carbonous gas,
of  chlorine and carbon.   Sulphur with bases  forms  bi-
nary compounds, called  sulphurets.  Steel is a  binary
compound formed of carbon and iron.  Oxygen in one,
two, three, and even  four  proportions,  forms a  great
variety of binary compounds; as  with sulphur it  forms
in the  highest proportion sulphuric acid, in a lower pro-
  *  For  the arrangement of metals and their properties, see Dictionary, arti
' lo  Metals 
                         527
portion it forms sulphurous acid,  dec.  The most impoi
' ant acids are mostly binary compounds.
  With the metals oxygen forms  oxides,  protoxides, d:c.
There are eight non-metallic oxides, viz.
     The Protoxide of Hydrogen, or Water,
         Peroxide of Hydrogen,
         Oxide of Phosphorus,
         Oxide of Carbon,
         Oxide of Chlorine, or Euchlorine,
         Protoxide of Nitrogen, or Exhilarating Gas.
         Deutoxide of Nitrogen,
         Oxide of Selenium.
  The metallic oxides are very numerous ;  the peroxide
of manganese is of great importance in  chemistry,  il
being  used  for  procuring chlorine, oxygen, die  The
deutoxide of iron  possesses magnetical attraction, and is
called the loadstone, or magnet.   The deutoxide of lead
is commonly known by the name of white  lead.   With
the  earthy  and alkaline  metals  oxygen forms  various
oxides, as the oxide  of silicon, or silex, the oxide of cal-
cium, or lime, the oxide of sodium, or soda, the oxide of
 potassium, or potash, die

                  BINARY COMPOUNDS.
                         Acids.
   Acids are distinguished by a sharp and pungent taste;
 they change vegetable blue colours to red, and combine
 with metallic oxides to form salts,  or to alkaline oxides
 i as soda and potash) in order to neutralize or be neu- 
528
tralized by them.   It was long believed that the acidify ■
ing power was confined to oxygen ;  hydrogen is now sup-
posed to possess this property; thus the  acids  are now
divided into  oxacids and hydracids.   The oxacids  arc
numerous ; some of the most important are,
   Nitric Acid, composed of Nitrogen and Oxygen,
   Sulphuric Acid,    „     Sulphur and Oxygen,
   Carbonic Acid,     „     Carbon, Oxygen, die
  There are four hydracids, viz. hydro-sulphuric, (usually  .
called sulphuretted  hydrogen,) hydriodic, hydro-chloric,
and hydro-selenic

              QUARTERNARY COMPOUNDS.
                        Salts.
  Salts are compounds of oxides with acids; as the acids
are binary compounds, the salts are  of  course  quarter-
nary or quadruple combinations, they are of three kinds ;
1st,  neutral,  presenting neither acid or alkaline proper-
ties ; 2d, with excess of oxide ; 3d, with excess of acid.
The  salts are divided into genera, each genus consists of
the combination  of one acid with various oxides, and  is
subdivided into three series, neutral, super, (over) and sub,
(under).  In all salts of the same genus, and  at the same
degree  of saturation, the quantity of acid is to the quan-
tity of oxide in a uniform proportion.

                  GENERA  OF SALTS.
  Borates.  The  most important species  is  the sub-
borate of soda.  It is found in some lakes. 
                         529
   Carbonates.   This genus is distinguished by being
decomposed with effervescence, owing to the escape of
carbonic acid.   Among  the most important species of
this genus are carbonate oflime, consisting of chalk, lime-
stone, die ; sub-carbonate of soda, commonly called soda;
carbonate  of ammonia, produced by the decomposition of
animal matter;  carbonate of iron, a valuable  mineral;
carbonate of copper, of various colours, as blue, green, die  ;
carbonate of lead is white lead ; sub-carbonate of potash is
the potash of commerce.
   Phosphates.   In this genus is the Phosphate of Lime,
which forms an important part of the bones of animals,
and is used for  the manufacture of  phosphorus.   Phos-
phate of Cobalt by calcining with alum forms a beautiful
colour called Thenard's blue.
   Sulphates.   The most common species which exist in
nature are those of lime and barytes.
   Sulphate of Lime is gypsum, or plaster of Paris.
   Sulphate of Magnesia is Epsom salts.
   Sulphate of Potash.  Alum  is a  double sulphate of
potash and alumine.
   Sulphate of Soda is Glauber's salts.
   Sulphate of Iron combined with nutgalls forms ink.
   Sulphate of Copper (Deuto) is copperas, or blue vitriol.
   Nitrates.  But three species of this genus are  found
m nature.  Nitrate of Potash is saltpetre ; it is of impor.
tant use in the  manufacture of gunpowder.  Nitrate of
Bismuth is used  in the manufacture of pearl-white.   Y/.
'rate of Silver is lunar caustic.
                           15 
530
   Chlorates.   More of this genus are found native.  It
 contains the Chlorates of Potash, (oxymuriate of potash,)
 Soda, Lime, die
   Hydro-Chlorates were  formerly  called muriates.
 When crystallized or dried, they  lose  the  hydrogen  of
 their acid, and  become  chlorides;  these in  their turn,
 when dissolved in water, form hydro-chlorates.   Hydro-
 Chlorate of Lime (muriate of lime) is of use in medicine
 and in chemical experiments.  Hydro-Chlorate of Ammo-
 nia is manufactured by the re-action of  marine salt upon
 the sulphate of ammonia.
   Chlorides.*   There are many metallic chlorides, as
 chlorine has  a strong affinity for  metals.   Chloride of
 Calcium is distinguished by having a great  affinity for
 water.   Chloride of Sodium is common salt;  its  proper-
 ties are known  in  all civilized countries.  Chloride of
 Soda has of late been found  useful in removing offensive
 gases from the atmosphere, and preventing infection from
 sick persons or dead bodies.   The chlorine is supposed
 to decompose  the noxious exhalations by uniting with the
 elements of which they consist, particularly the hydrogen.
 Chloride of Lime is commonly called bleaching powder.
 Chloride of Mercury is subdivided  into the  bi-chloride.
 (deuto-chloride,) which is corrosive sublimate, and the
proto-chloride, which is calomel.   There  are other im-
 portant species in this genus  ; as the Chlorides of Manga-
 nese, Iron, Silver, dec

  - The chlorides, although mentioned here, arc not proper salts; thry .-m
 iinalo-.-ous to oxides: iodides, and bromides. 
                          531
  Hydriodates.   But  one  species of importance  is
known, viz. the Hydriodate of Potash.
  Chromates.  The most important species is the Chro-
mate of Lead, which is a beautiful yellow.
  There  are other genera of  salts, as the nitrites, sul-
phites, phosphites, die, which are formed by combinations
of nitrous, sulphurous, and  phosphorous acids with bases :
the properties of these, although in many respects  differ-
ing from the salts formed with the higher acids, are not in
general very dissimilar.
  The organic kingdom furnishes an  almost  infinite va-
riety of important compounds;  vegetable acids are very
numerous ;  the  acetic, tartaric,  oxalic,  malic,  kinic, die,
are all of use  in medicine and  in the arts.   Among the
vegetable alkalies are morphia, the  narcotic principle  of
opium, cinchonia and quinia, extracts of the  Peruvian
bark, with  many others.   Oils, resins,  wax, alcohol.
ether, sugar, starch, tannin, lignin, and various colouring
substances, are all products of the vegetable kingdom.
Salts are formed by the union of the vegetable alkalies
with acids, as the sulphates of quinine, of morphine, &c.
  For the characters of nitrates, dee, see Dictionary.
  Animal Chemistry presents a new set of compounds,
as fibrin, gelatine, acids, and oils ; it investigates the com-
pounds of all  animal matter, as bones, teeth, blood, and
the various secretions; and traces all these to their final
or  ultimate elements, oxygen,  hydrogen,  carbon,  and
nitrogen.
                    THE ENJD, 
                     ERRATA.

Page 30, 15th line from top, insert other before ' vegetable.
 "    68, 12th line from top, for 1825 read 1225.
 ■'   187, dele last sentence in page.
 ■   188, J5th line from bottom,, for object read objectors 
 
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