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MEMOIRS
OF THE
COLUMBIAN CHEMICAL SOCIETY,
OF PHILADELPHIA.
VOLUME I.
PUBLISHED BY ISAAC PEIRCE,
    JVo. 3, South Fourth Street.
1813.
 
             District of Pennsylvania, to wit:

%  "     ***     BE IT REMEMBERED, That on the Sixth
*  SEAL. *  day of October, in the Thirty-seventh year of
*         *  the Independence of the United States of Ame-
 ********   rica> A. D. 1813.   ISAAC PEIRCE of the said
 District, hath deposited in this office the Title of a book, the
 right whereof he claims as Proprietor in the words following,
 to wit:

 Memoirs of the  Columbian Chemical Society, ofPhiladelfihiat
                        Volume J.

   In Conformity to  the Act of the  Congress of  the United
 States, intituled, "An Act for the Encouragement of Learn-
 ing, by securing the Copies of Maps, Charts and Books,  to the
 Authors and Proprietors of such Copies during the times there-
 in mentioned."  And also to the Act, entitled, " An Act sup-
 plementary to An Act, entitled  " An act for the Encourage-
 ment of  Learning, by securing the Copies of Maps, Charts,
 and Books, to the Authors and Proprietors of such Copies du-
 ring the Times therein mentioned," and extending the  Bene-
 fits thereof to the arts  of  designing, engraving, and etching
 historical and other Prints."
                             D. CALDWELL,
                     Clerk of the District of Pennsylvania. 
PREFACE.
     IN presenting to the public the first fruits of
the Columbian Chemical Society, it may not be
amiss, to give a short history of its rise and pro-
gress.
   The Columbian Chemical Society was founded
in the month of August 1811,  by a number of
persons desirous of cultivating chemical science,
and promoting the state of philosophical enquiry.
And although the number of members has not in-
creased rapidly ; yet, from the zeal manifested by"
the few who compose the Society, in investigating
scientific topi s, there is every reason to believe,
that the period  is  not far distant, when this insti-
tution will rank high in respectability.
   From the nature of the subject to be investiga-
ted,  it followed, that essays would frequently  be
offered by its members.  Hence arose that multi-
plicity of dissertertations from which  this selection 
IV
PREFACE.
has been  made.  *The appearance, however,  of
some papers, whose relation to chemistry, is scarce-
ly, if at all perceptible, prompts us to make one
remark. One of the articles of the constitution ex-
pressly declares, that communications may be  on
subjects either chemical or philosophical.
  The contents of the volume, are chiefly original,
partly speculative, and partly practical. The great
variety of topics investigated, the novelty of many
of the essays, will, it is hoped, render the whole,
somewhat interesting.   In addition to the papers
of the Society, it has been deemed proper to pub-
lish the Constitution, together with a list of officers,
members, &c. &c. 
CONSTITUTION
                OF  THE



COLUMBIAN CHEMICAL SOCIETY.
     Deeply impressed with the importance of an
association, devoted to the investigation of scienti-
fic subjects, we the subscribers mutually agree to
form ourselves into a society, to be governed by
the following Regulations:
   1st.  That this society shall be known by the ti-
tle  of the Columbian Chemical Society of Phila-
delphia.
  2. The officers shall consist of a President, two
Vice Presidents, a Corresponding Committee, se-
cretary, Treasurer, and Orator, to be elected by
ballot, in the month of January in each year, and
in case of vacancy by death or resignation, it shall
be supplied by special election. 
vi               Constitution, &fc«
   3.  The duty of the  President  shall be to pre-
serve order, regulate debates, and conduct the bu-
siness generally.
   4.  The Vice Presidents shall preside in absence
of the President, and in case of the absence of both
Y ice presidents,  a chairman shall be elected pro
tempore.
   5.  The Secretary shall keep fair, minutes of the
transactions of the society,  preserve all papers,
give due notice of all meetings, call the roll at the
opening and close of each meeting and mark down
absentees.
   6.  The Treasurer, giving security, shall receive
in trust for the society, the funds thereof, dispose
of the same on order,  keep  regular  entries, and
once in 3 months, produce his accounts for the in-
spection of the society. In case of resignation, he
shall transfer to his successor, on order from the
President,  such of the society's property, as he
may possess.
   7.  An oration on some chemical subject shall
be  delivered  within two months after the com.
mencement of the  medical lectures in the Univer-
sity of Pennsylvania, in each year.
   8.  The stated meetings of the society shall be
held on the third Wednesday of every month.
   9.  Every member  shall be fined 12*  cents for
absence each roll, unless satisfactory reasons be
offered.
   10. Any member behaving in a disorderly man-
ner, shall be expelled by consent of f of the mem-
bers present. 
Constitution^ Esfc.
vii
    11.  Any person desirous of membership shall
 be proposed and seconded at one meeting, and be
 ballotted for at the next;  previous to the election,
 he shall read  an original  essay on some chemical
 subject on which any member  may  speak  not
 more than ten minutes. Every candidate shall have
 two thirds of the  votes of the  members present in
 his favor to procure election, and shall pay 2 dol-
 lars into the hands of the treasurer.
    12.  The society  shall appoint,  once in each
 month, some member to read an  original chemi-
 cal essay, for neglect of which, the member so ap-
 pointed, shall be fined one dollar.
    13.  No member  shall be compelled to read
 more than one  dissertation in  the course of six
 months.
    14.  Aiiy member being elected to office, and
 refusing to serve,  shall be fined one dollar.
    15.  The Constitution shall  be revised annually,
 and the revision  shall take place in  January;  no
 alteration shall be made in it without the consent
r of two thirds of the members present.
    16.  Six members shall constitute a quorum and
 may proceed  to business.
    17.  All bye-laws not inconsistent with these ar-
 ticles, shall be equally binding.

    Officers of the Columbian Chemical Society.
 Hon. Thomas Jefferson, Esq. Patron.
 James  Cutbush,  Esq. Profess. Nat. Philos. Che-
   mistry and Mineralogy  in St. John's College.
    President. 
viii
Alembers fcfc.
George F. Lehman } ^ presidents.
Franklin Bache     3
John Barnes M. D. )
John Lynn M. D.  > Corresponding Committee.
Charles Edwards.  )
John C. Heberton,  Secreatry.
James J. Hamm, Treasurer*
John R. Barnhill, Orator.

              Junior  Members*
Abraham Armstrong, of Santa Cruz.
Thomas F. Breintnall, Esq. of Philadelphia:
Francis H. Brognard, of New-Jersey.
Edward Brux, of France.
D. Burwell, of Virginia.
Samuel F. Earl, of Philadelphia.
Lewis Gebhard, of New York.
George Grey, of Philadelphia.
Thomas C. Hall, of Maryland.
Henry  Hawkins, of Maryland.
Henry Neill, of New-Jersey.
T. W.  Robertson, of South Carolina,
Wm. Shippen, of Philadelphia.

             Honorary Members.
M. Adet, of France.
F. Aigster,  M. D. Lecturer on Chemistry at
   Pittsburg.
Mr. Allen, of Great Britain.
Right Hon. Sir Jos. Banks, Brt. K. B. P. R. S.
Benjamin Smith Barton, M. D. Profess, of Mat.
   Med. Nat. Hist.  & Bot. in Univer. of Pennsyl. 
        of Columbian Chemical Society.       ix
M. Berthollet, of France.
A. Bruce, M. D. Profess, of Mineralogy, Colum-
  bia College, New-York.
Chas. Caldwell, M. D. Lecturer on the Inst, and
  Practice of Medicine, of Philadelphia.
M. Chaptal, of France.
J. Cloud Esq. of Philadelphia.
Saml. Conover, M. D. of Philadelphia.
Hon. Thos. Cooper Esq. Profess,  of Chemistry,
  Mineralogy and Geology, in Carlisle College.
Jno.  Redman Coxe, M* D. Profess, of Chemistry
  in the University of Pennsylvania.
Edward  Cutbush,  M. D. Surgeon in the U. S.
  Navy.
Jno.  Dalton  Esq. F. R. S. E. of Manchester.
Sir Humphrey Davy, Knt. L. L. D. Sec. R. S.
  London.
Jno.  Davy, Esq. London.
Elisha De Butts, M. D. Profess, of Chemistry in
  the College of Maryland.
J. A. De Luc, F. R. S. England.
M. Deyeux, France.
Benj. De Witt  Profess, of the Institutes of MedU
  cine and Lecturer on Chemistry, N. York.
Jno.  Syng Dorsey, M. D.  Adjunct Profess, of
  Surgery, Univer. of Pennsylvania.
Jno.  Griscom, Lecturer on Chemistry, N. York.
Robert Hare, Profess. Nat. Philos. Univer. Periri.
C. Hatchett, Esq. F.  R. S. London.
Abbe Hauy, France.
Wm. Hembell, Esq.  Philadelphia.
Wm. Henry, M. D. F. R. S. Manchester. 
X
Members &c.
Wm. Herschell, L. L. D, F. R. S.  England.
T. T. Hewson, M. D. Philadelphia.
Jno.  Hope, M. D. Profess. Chemistry Edinburg.
David Hosack, M. D. Profess, of the Theory and
  Practice of Medicine and of Clinical  Medicine
  in the University of New York.
Henry Jackson, M.  D.  Profess, of Chemistry,
  Athens College, Georgia.
M. Boillon Lagrange, France.
M. Lussac, France.
His Excel> James Madison, Esq. L. L. D. Presi-
  dent of the United States of America.
John Manners, M. D. F. A. N. S. of Philadelphia.
Jno.  Mc. Lean, Profess,  of  Chem.  Nat. Philos.
  Princeton College.
Hon. Saml. L. Mitchell, M. D, F. R. S. E. Pro-
  fess. Nat. Hist.  Botany, New York.
Thos. D. Mitchell, M. D. F. A. N. S. of Phik-'
  delphia.
M. Monge, of France.
M.. Guy ton Morveau of France.
Jno.  Murray, Esq. Lecturer on Chemistry, Mate-
  ria Medica and Pharmacy,  Edinburg.
Wm. Nicholson Esq. London.
Jno.  C.  Osborne, M. D. Profess. Inst, and Prac-
  tice of Medicine, Columbia College, N. York.
M. Parmentier, of France.
Joseph Parish,  M. D. of Philadelphia.
Robert Patterson, A. M. Profess. Mathematics, &
  Leturer on Nat. Philos. University of Penn,
G. Pearson M. D., F. R. S. of London.
W. H. Pepys,  Esq.  F. R. S, England, 
       Of the Columbian Chemical Society.     xi
 M. Pelletier of France.
 Nathaniel Potter, M. D. Profess, of the Theo. ancj
   Practice of Medicine, University of Maryland.
 M. Proust, Professor of Chemistry Madrid.
 Benjamin Rush, M. D. Profess, of Inst, and Prac-
   tice of Medicine, University  of Pennsylvania.
 M. Seguin, France.
 Hon. Adam Seybert, M. D. of Philadelphia.
 David Shepperd M. D. of New-Jersey.
 Benjamin Silliman, Professor of Chemistry,  Yale
   College.
 John S. Stringham, M. D. Professor of Chemis-
   try, N. York.
 JoelB. Sutherland, M. D. F. A. N. S.  Philadel.
 M. Thenard, France.
 Thomas Thomson, M. D. F.  R. S.  E. Lecturer
   on Chemistry, Edinburg.
 Alexander Tilloch, Esq. M.  R. S. et F.  S. At
   London.
Jared Troust, M. D. Lecturer  on Mineralogy in
   the Academy of Natural Sciences.
 M. Vauquelin, France.
 Laurence Washington, Esq. Virginia.
 Caspar Wistar, M. D. Profess. Anat. Univer.  of
   Pennsylvania.
Chas. Wistar, Esq. of Philadelphia.
 Wm. Hyde Wollaston, M. D. Sec. R. S. London, 
           TO  THE READER.

  Owing to the difficulty that we  necessarily  la-
boured under, in commanding the attention of so
many different authors  to the  correction of their
essays in the proof sheets, as well as to the  ob-
scure hand in which some of them were written,
many typographical errors have escaped;  but we
hope that  generally they are of such a nature, as
not to render the meaning ambiguous;  it is upon
this  ground we claim a portion of the authors' as
well as the reader's indulgence.
                         THE PUBLISHER. 
CONTENTS.
                                                   Page.
Remarks on the Phlogostic and Antiphlogistic Systems of
   Chemistry.   By Thomas D; Mitchell, M. D.  -  -  -    5

An Inquiry into what circumstances will warrant us justly
   to. reckon a substance a principle of a common property
   of any set of bodies.  By Franklin Bache.   -  -   -    -  15

On the prognostic  signs of the weather.  By James Cut-
   bush.  --------.___.._-  »26

Experiments and observations on the effect of light on ve-
   getables and  upon the physiology of leaves.  By John
   Manners, M. D.  ----------   -     47

Speculations on lime.   By Joel B. Sutherland, M. D.  -   -  58

Remarks on heat.  By Thomas D. Mitchell, M. D. -  -    63

On the oxyacetite of iron as a test or re-agent for the disco-
   very of Arsenic.  By James Cutbush. ------  f&

Thoughts on  the  principle of excitability.  By George
   Ferdinand Lehman. ----------      7-5

Analysis of a Mineral spring, at the Willow Grove, Mont-
  gomery County, Pennsylvania,  By Johr Maimers, M. D.
  and Thomas D. Mitchell, M. D......       9.,

An Inquiry whether Mr. Berthollet was warranted, from
  certain experiments, in framing the law of chemical at- 
xiv
Contents.
   finity, " that it is directly proportional to the quantity ot*
   matter."  By Franklin Bache.  ------    96

Qn muriatic and oxy-muriatic acids, combustion, &c.  By
   Thomas D. Mitchell, M.D.  -     -----   102

On the production of Sulphuretted Hydrogen by the ac-
   tion of hi tck Sulphuric Acid, diluted with Water  on
   Iron Nails.  By John Manners, M. D.   -      -  -   118

On the emission of oxygen gas by plants. By George Fer-
   dinand Lehman.   -  .---...---    12t

Analysis of Malachite, or green carbonate of copper of Per-
   kioming, Pennsylvania.  By Thomas D. Mitchell, M. D. 125

Thoughts on the  expediency of changing parts of the che-
  mical Nomenclature. By Franklin Bache.   -  -  -   I2f

Remarks on Putrefaction. By Thomas D. Mitchell  M. D. 135

A few remarks upon the nature of the nervous  influence.
   By Joel B. Sutherland, M. D.........145

Chemical view of secretion. By Thomas D. Mitchell, M. D. 153

Observations upon the effects of various gases upon the'liv-
   ing Animal Body.   By Edward Brux, of France.  -  -   158

Analysis of professor Coxe's essay on  combustion and Aci-
   dification. -------     -----     174

Experiments and observations on putrefaction by John Man-
   ners, M. D.   ---'---,--__   -   198

Observations on the formation of muriate of potash  in the
   process of preparing the hyperoxymuriate of potash by
   William Hembel.jun. Esq. --------    202

Analysis of the Bordentown, (N.  J.) spring.  By Samuel F.
   Karl...............-   205 
Contents.
xv
Report of the committee to whom was referred the analysis
  of certain  ores, presented through the medium of Tho-
  mas BrientHall, Esq. to the Columbian Chemical Socie-
  ty-  ................208

Remarks on  the atmosphere, read before the Columbian
  Chemical Society, by Thomas D. Mitchell, M. D. -  -  311

A new method of mounting  Woulf's Apparatus in  which
  the tubes of safety are superceded,  by William Hem-
  bell, jun.  Esq. Communicated to the society  by John
  Maimers, M. D.  -   -  -.........218 

.^F . 
MEMOIRS
                    OF THE

COLUMBIAN CHEMICAL SOCIETY.
Remarks on the Phlogistic and Antiphlogistic Sys*
  terns of Chemistry.  By  Thomas D. Mit-
  chell, m. d . Fellow of the Academy of Natu-
  ral Sciences of Philadelphia.  Honorary mem*
  her of the Cnhimhi.an Chemical Society, £sfc.

  THE  grand dispute, between the Phlogistians
and Antiphlogistians, appears to consist in this :
the former believed, that in  combustion, the body
burnt, parted  with something, supposed to be
Phlogiston or the  principle  of  inflammability;
They imagined, that in order to restore  its com-
bustibility, it must again receive the principle of
inflammability, in other words, that Phlogiston must
re-enter its composition.   The  Antiphlogistians
with more philosophical reason, supposed, that in
combustion, the burning body, instead of losing,
combined with  something,  and, that in order to
restore the combustibility, this  substance, which
had been combined during  combustion, must be
separated.  This peculiar matter was oxygen,
                      B 
 o*       Remarks on the Phlogistic and
   Numerous have been the advocates of these very
 opposite points.   They have laboured hard in the
 field of experiment and wandered far in the mazes
 of speculation. But, in all disputed subjects,  the
 balance finally preponderates in favour of one or the
 other sentiment, and in the case before us, the An-
 tiphlogistians have proved victorious. Their lead-
 er, the immortal Lavoisier has been crowned with
 laurels, durable as fame.   Before him fell the stern
 votaries of  the  Phlogistic system.   His theory,
 says Dr. Black, is bold and ingenious, and science
 has cause, greatly to deplore the death of so emi-
 nent  a philosopher.   Had this great man  es-
 caped the blast of tyranny and eluded the storm of
 despotism, the science of Chemistry would have
 shone with tenfold splendor at this day.  Extrava-
 gancy in speculation would have been silenced by
the cool deliberation of reason.
  Notwithstanding the apparent death blow that
the Phlogistic  system  received,  there  appears
 some probability of a renewal of the  old dispute.
The various researches of Davy have  given rise
to doubts respecting  the  tenable nature of  the
whole Antiphlogistic system.  In consequence of
these investigations, some chemists of the present
day are desirous of establishing as an axiom, the
existence of a principle of inflammability in all in-
flammable bodies.  This, in fact, is very little, if
any thing different from the Stahlian theory.
  In my opinion, however, there is no more just
ground for the admission of the Phlogistic  system
■it this day, than there was in the time of Lavoisier 
       Antiphlogistic Systems of Chemistry.     7

 Place the practical inquiries  of this  philosopher
 in one scale, together with reasonable speculation,
 and in the opposite scale place all the vague hypo-
 theses that have ever been or are now tolerated, and
 let candor decide.
   We are told that Hydrogen has been proved to
 exist in Carbon,  Sulphur, Phosphorus, &c. as an
 essential component part.  Some experiments have
 been made to prove that  Carbonated Hydrogen
 could be obtained by exposing to great heat, a
 quantity of charcoal perfectly freed from  water.
 From such  experiments, the  inference has been
 made, that hydrogen necessarily  existed in char-
 coal.  The  same was done with regard to sulphur,
 phosphorus, &c.
   In, these experiments,  we have  no doubt that
 accuracy  was  observed  so far as concerned the
 process. But we have good reason to believe, that
 the nature of the products was misunderstood.
   It may  be thought strange,  that in  a subject of
 so much importance, I should resort to but one ex-
 perimental proof in favour of the position I attempt
 to support.   But when  the nature of that single
 proof and its obvious importance is discovered, it
 will appear to swell into a host of arguments.
   In order to bring the  reader fairly into an ac-
 quaintance with my design, I must state some ex-
 periments made  by the  late Dr. Woodhouse.
 These were designed  as insuperable barriers to
 the Antiphlogistic system.  For the professor can-
didly acknowledges his conviction of the fallacy of
that system, as  will appear by a  perusal  of his 
8       Remarks on the Phlogistic and
" Appendix to  Parkinson's Chemical  Pocket
Book."*  The Doctor performed an experiment,
much celebrated on account of the zeal manifested
in it, to obviate certain objections that might have
been urged against his inferences. He mixed char-
coal with scales of iron,  both freed from water by
previous exposure to a red heat.  His object was,
by placing the mixture in a proper vessel with con-
venient appendages,  to determine  what  gasses
would result.   According to  the Antiphlogistic
theory, no hydrogen could be obtained in this pro-
cess, yet the Doctor tells us that a gas containing
hydrogen was procured.  He goes further and as-
serts, thathe has procured inflammable air, (meaning
hydrogen) by  heating a  mixture of flowers of zinc
and charcoal.  From these results  the  Doctor
formed his objections to the new system of chem-
istry ;   and   in  fact, had  his  inferences been
correct, this system must have sustained some in-
jury.   Admitting the correctness of the Doctor's
experiment, some chemists would gladly seize the
opportunity of attempting to prove that the sup-
posed  hydrogen came from the charcoal,  others
would look to the iron for this product,  and hum-
bly hope to restore to Phlogiston the place it once
occupied.   Among the latter was Dr. Priestley.
This philosopher, though a true favorite of genius,
fell into the grossest errors.   He performed expe-
riments very similar to  those already mentioned
as performed by Dr. Woodhouse.  The products
  * I am awave, however, that the Doctor afterwards recanted, and
resumed his attachment to the new system. 
      Antiphlogistic Systems of Chemistry.     9

were similar and Dr. Priestley ventured to account
for the supposed appearance of hydrogen, by the
evolution of Phlogiston.  To this effect, he wrote
several pages, some of which may be found in the
1st. and 2nd.  vol. of the New York Medical Re-
pository.  The  results of the  experiments, al-
though fallacious as will hereafter appear, called
forth  the energies of many  respectable chemists.
They admitted, very improperly too, the the cor-
rectness of Dr.  Priestley's experiments and dis-
puted his inferences  only.  Mr. Adet, a French
chemist, in an answer to Dr. Priestley, endeavoured
to account for the appearance of Hydrogen in the
experiment we have  mentioned, by*saying that
charcoal  very  often  contained  this substance.
Thus we see that experiments, which we hope to
show  were  fallacious,  and inferences which of
course must be unfounded, have involved  in them
the correctness of  the  famous Antiphlogistic
system.
   But the opposition thus excited, ephemeral in its
nature, soon vanished.  Anxious to efface the blot
necessarily cast on the new theory by such investi-
gations, Mr.  Cruikshank of Woolwich ventured to
repeat the experiment which had produced  such
effects on the mind of Dr. Woodhouse.  It will
be also recollected, that this experiment is similar
to some of Dr. Priestley's made with a view to the
support of the Phlogistic system.
   Mr. Cruikshank accordingly performed the ex-
periment and the result seemed at first to confirm
the inferences of Dr. Woodhouse. An inflammable 
  10       Remarks on the Phlogistic and
  gas was produced as had been asserted.   But the
  decision of a scientific point, highly important in its
  nature was not to be rested on  the evidence of
  mere appearance.   Inquiry was  therefore urged
  still further, and an analysis of the  gasseous pro-
  duct was effected.  And here let it be remarked,
  that while truth was about to erect her standard, a
  valuable accession  was also  made to the fund of
  Chemical science.  The product was found  to be
 a substance unknown at that day, and has ever  since
 been  reputed  as  the discovery of Cruikshank.
  The inflammable air of Woodhouse proved to be a
 compound of oxygen and  carbon, 59 of the former
 to 41  of the/Ater in the 100. It is called Gasseous
  Oxide of Carbon, and though inflammable, it con-
 tains no hydrogen.* .....'.
   Here then we perceive the effect of delusion in
 experimental inquiries where the mind is biassed in
 favour of any opinion.   The result of this experi-
 ment is perfectly conformable to the mode of rea-
 soning pursued by the Antiphlogistians.
   Now, let us reflect a moment on the consequen-
 ces of a single mistake in experimental researches.
 The error of  Priestley and Woodhouse, did not
 operate merely on themselves, but like an ignis
fatuusy it led thousands astray.  Yet we see  that
 the indefatigable labours of one man have sufficed

  • It may not be amiss to mention, that Dr. Priestley has attempted
 to reconcile Mr. Cruikshank's discovery with his favourite system ;
 but the attempt, in my opinion, is altogether ineffectual.  Dr. Priest-
ley's paper on this subject may be found in  the 5th. vol. of Med.
Rep 
      Antiphlogistic Systems of Chemistry.   11

to expunge this mistake from the minds of thou-
sands.  His  correctness  is admitted  by all who
have repeated the experiment.
   When we are told that carbonated hydrogen was
procured by  heating charcoal freed from water,
we have just  cause for believing that no such pro-
duct was obtained.   The  same  may  be asserted
with  regard  to  phosphorus, sulphur, &c.   The
probability is, that in all these cases, oxides were
produced, in  a gasseous form, as in the case of
gasseous oxide  of carbon.  If Priestley, Wood-
house and others, among the most celebrated che-
mists who have ever lived, were  deceived merely
by mistake and from that deception were led to
adopt false theories, we need not wonder that others
less famous in the scientific  world should be de-
luded in a similar manner.
   Much has  been said relative to a  principle of
inflammability in inflammable bodies;  but  ad-
mitting its existence as a possible thing,  I see no
necessity for  it.  No body can undergo combus-
tion without the presence of oxygen, even hydro-
gen itself will not burn without it, and yet this is
urged as a principle of inflammability.
   In the experiment as performed by Woodhouse,
Cruikshank &c. the iron was revived, consequent-
ly rendered combustible.   If the Phlogistic sys-
tem be correct, the iron must have received an ac-
cession of the inflammable principle or hydrogen,
but so far from this, not a particle of hydrogen was
present.   The  iron was revived and  rendered
combustible,  not by the restoration of the principle 
12       Remarks on the Phlogistic and

of inflammability, butas the beautiful system of La-
voisier justly teaches us, by an abstraction of its
oxygen.   By this fact, also, one of the conclusions
made by Mrs. Fulham in her essay  on combus-
tion, is completely overturned.  That  writer has
asserted, that no metallic reduction can take place,
except hydrogen be present.  But  we have shown
that iron has been  reduced,  independent of the
agency of hydrogen.
  It will be evident to all, that I have not aimed
to prove the non-existence of an inflammable princi-
ple ; all I have attempted is to show the fallacy of
means hitherto employed to prove that there is such
a principle.  It remains therefore with its advocates
to bring forward better  evidence  in  support of
their position.   I do not believe it of importance
to  make any effort to disprove this sentiment, be.
cause, there appears to me, no necessity for a prin-
ciple of inflammability.  And I believe  that  all
important phenomena can be accounted for inde-
pendent of such an agent.
   I shall now conclude with a few general re-
marks.  And in the first place,  I would observe,
that while the doctrine of an inflammable principle
appears to me incorrect, it seems likewise unphi-
losophical.   And while  I say  this, I am as willing
to admit the error so often made, in the use of the
term, principle of  acidity.   Both are alike im-
proper.   It would be just as philosophical, when
speaking of a neutral salt, to assert, that the acid
constituted the principle of neutrality, as, that it
resided, exclusively, ia the alkali.  How absurd 
      Antiphlogistic Systems of Chemistry.    13

does this appear !  shall we then be excused, when
we say that such a body is combustible, if we as-
sert that the principle of inflammability belongs to
one agent? or, speaking of an acid, shall we be al-
lowed, to call one of its constituents, the acidifying
principle? I grant that  acids are  found generally
to contain oxygen, but does this prove it to be the
efficient cause of acidity ? Pray, let me ask, where
would be the lists of acids, if the bases as they are
styled, were not  called into action ? They are as
much principles of acidity, as oxygen, and it is an
abuse of terms, a misapplication of words, to say
that this or that is the principle of inflammability
or of acidity.  Inflammation and acidity  are effects
resulting from  the action of relative causes and
not attributable to a single agent or principle.
   We do not seek for a secreted something in the
base of an acid, to make it assume the characteris-
tic of acidity, or  to render  it different  from any
other acid.   The great difference in obvious quali-
ties Is sufficient to account for the immense varia-
tion observed.   So, in combustion; oxygen and a
combustible body are present, and I ask where is
the ground for searching an inflammable principle,
a hidden, ideal ? the difference in appearance which
is  observed on burning phosphorus and  a piece of
wood is readily explained, by the obvious dissimi-
larities exhibited  by these substances.  Why not
admit, that phosphorus and iron, considered either
as  simple or compound, will burn  in contact with
oxygen, independent of the assistance of an agent,
called-forth by fancy, when we grant that barytes,
                    C 
14     Remarks on the Phlogystic fcfc.

lime or any other base may form a neutral salt when
an acid is added, without going in quest of an un-
known non-entity.
  I may be charged with, vainly speculating to no
purpose, by some who are prejudiced in favour of
one or the other system.   But as we are irresista-
bly compelled to think and as I have been accus-
tomed to  reflect on this subject, it would  have
been an act of injustice to my feelings to have re-
frained from these observations.  They are there-
fore, respectfully submitted to  the candid exami-
nation of all and I trust they may be at least so far
useful, as to excite a more general inquiry on sub-
jects of this nature.

 Wednesday, October, 23</. 1811- 
AN ENQUIRY
Into what circumstances will warrant us justly to
  reckon any  substance a principle of a  common
  property of any set of bodies.  By Franklin
  Bache.  Member of  the Columbian Chemical
  Society.
  To render a substance a principle of any com-
mon  property  which  may  exist in any set of
bodies, we conceive it not only requisite to prove
that it  exists in  all the bodies possessing the
common property; but that when united in a suf-
ficient proportion with any body simple  or com-
pound, which is susceptible of the common proper-
ty,  that  it  should appear; thus, to apply  this
definition to the particular investigation, which is
to be entered into  in the  present enquiry, (which
is,  upon what  ground we shall be  warranted in
believing any  substance, a principle of acidity,
in Chemistry,)  it will be not only necessary,  that
we  should prove that  any  particular  substance
exists in  all bodies  possessing the property of
acidity, but also, that when presented in sufficient
quantities, under  proper circumstances,  to  any
substance*, capable of  acidification,  acid proper-
ties should appear.
  As Hydrogen is the only substance  which has
contended the palm with Oxygen, for being the
principle  of .acidity, our enquiries shall be con-
,# 
16              An Enquiry He.
fined to weighing  the  respective claims of these
two  important   substances to  that honour: al-
though it is an hypothesis that has raised  Hydro-
gen to the exalted  station of a competitor of Ox-
ygen, yet, for the purpose of refuting its preten-
tions more completely, we will suppose that hy-
pothesis  a well ascertained  fact.   The hypothe-
sis to which we allude, is that which  supposes
that  hydrogen is a constituent in all acids ; from
which the conclusion is drawn  by some, that, as
the belief that  oxygen  was this  principle,  was
founded upon the  circumstance of its presence in
all acids, therefore hydrogen  has an  equal  claim
with oxygen.   But we contend that the very cir-
cumstance, of the possibility of two substances
existing common  to i.ny  set of bodies (and we
not  only think  it possible, but  likewise very
probable,)  should have taught the advocates of
this doctrine, that that  was not a proper definition,
which  was founded  on the circumstance merely,
of a substance being common to any set of bodies;
and why ? the reason is obvious;  for if it were a
proper definition, then  two substances could inde-
pendently of each other be capable of producing
acidity, which is impossible.
   Such were the reasonings which led us to seek
for some other  more complete  definition ;  which
we feel  confident we have discoverea in  that
which we mentioned in the beginning of the en-
quiry.
   Let us enquire  how the two substances Oxy-
gen and Hydrogen agree with the definition  : with
 
               An Enquiry &e.              17

the first part,  we have admitted they both agree,
and if the decision rested upon this point alone,
the matter would be completely  ambiguous ;  but
this is far from being the case, as something  fur-
ther  is necessary before  we can decide the ques-
tion, and this is, whether acidity is produced when
either substance is presented in sufficient quanti-
ties under proper circumstances to any  other sub-
stance, either simple or  compound which is sus
ceptible of acidification.
   Let us now enquire if Hydrogen produces acid-
ity when  united  to  any other substance capable
of acidification;   we  contend  that in  no  case
it does even in appearance, except  in sulphure-
ted Hydrogen ; in the consideration of which sub-
stance, the force of analogy, the possibility of its
having Oxygen in its combination  from the na-
ture of the  ingredients necessary for its produc-
tion,  as  being muriatic acid—water—iron—and
sulphur, and from the small  number of analyses
which have been yet  made, all  conspire to make
us believe  that oxygen must  be present in this
substance;  in short  when  we consider that  Hy-
drogen can unite with two analogous substances,
in the form of Carbureted  and Phosphureted Hy-
drogen gases withoutproducing acidity, we,are led
involuntarily  into the belief, that that substance
which is called sulphureted hydrogen,  might  with
more propriety be considered as  a  compound of
 muriatic  acid gas and  sulphuric acid, or if the
 conjecture be prefered, as Muriatic acid gas, hold-
 ing a small quantity of sulphur in solution. 
 18             An Enquiry, He.

  But yet lest there  should be  still some  who
conceive that  the  admission of  the presence of
hydrogen in all ternary acids, and in one  binary
in which Oxygen is solely the other  constituent
invalidates the belief in  Oxygen  as the prin-
ciple  of  acidity,  we shall enter into a set of
arguments fitted for persons  of  this mode of
thinking; for this purpose it will  be  necessary to
premise two things.   1st. That we  shall confine
ourselves to the consideration of such anumber of
binary acid compounds, as a belief in the presence
of hydrogen in all metals, as well as in  sulphur
Carbon and  Phosphorus will  necessarily limit
us to—the reason of this limitation will be obvi-
ous, when it is considered, that these compounds
afe the only acids  in which both Hydrogen and
Oxygen do not exist, or if they do, not in combi-
nation with any other substance   2nd. We must
reason upon the supposition that  a certain matter
is decided in  a certain way, which we candidly
admit is not decided in any way, or in other words
we must suppose that hydrogen is the base of the
Muriatic acid.   At first view it may not seem that
the decision of this point has any very direct re-
lation; to  the subject we are discussing; but we
hope  to shew in the sequel, that the assumption of
this circumstance as a fact, is not necessary only,
but indispensible in the decision, whether oxygen
can or cannot  be demonstrably proved to be the
princible of acidity.
  Let us now consider the binary acid compounds
limited, as we have before stated.—They* are 
An Enquiry, He,              19
   1st.   Oxygen  and Nitrogen  forming Nitric
Acid.
   2nd.   Oxygen and Hydrogen forming MurL
atic Acid.
  Here it is perceived are omitted all the vegeta-
ble acids, and the five Metallic, together with the
Sulphuric  Carbonic and Phosphoric  acids; the
former, because they are known to contain hydro-
gen, the latter, because they contain it by the sup-
position.
  Let us consider the first acid mentioned, name-
ly the Nitric: here then by this chemical combi-
nation, a vast change has taken place in the pro-
perties of the bodies, concerned in the  combina-
nation;  the most striking of which is, their sour-
ness, or what is usually termed their acidity, now
this acidity  must either  arise from the  Oxygen,
or the Nitrogen or from both; but it does not
arise from both, for if it did, Oxygen alone could
not produce the same effect, with another body*
totally different in its properties as Hydrogen, with
which it forms Muriatic acid; neither does arise
from the Nitrogen, because if it did, this substance
when united to Hydrogen would form an acid, but
on the contrary,  it forms a substance having dis-
tinctly  metallic properties, and known to ]>e the
basis of volatile alkali ammoniac.  So that as we
have disproved two of the three ways in which
the acid properties could arise, we may safely con- 4$
 elude negatively, that the third, which supposes
 oxygen, is the cause of the acidity.   But can we
 come to the same conclusion  by positive reason- 
 20            An Enquiry, He.
 ings ? we answer, most certainly; thus if it be the
 oxygen which causes the acidity,  it will,  when
 presented to Hydrogen form an acid,  but is this
 the case ? yes, for in this combination in a certain
 proportion it forms the  Muriatic acid.  So  that
 we arrive at the  same  conclusion,  whether we
 reason positvely or negatively.
    These reasonings will also have a tendency to
 demonstrate the fallacy  of  an opinion, most in-
 geniously supported by  our  President at a late
 Meeting of the  Society;  he says,  (speaking of
 the dispute concerning the principle of acidity) he
 conceives it to  be  completely unphilosophical,
 and that in no case  can an effect produced  by a
 chemical  composition be  reasonably  refered to
 one of the ingredients only, but that they must
 both necessarily concur, in producing the proper-
 ties generated; now we will venture to say that
 these erroneous deductions  of the  gentlemen to
m
 have arisen, entirely from a hasty analogy, referring
 what  happens in combinations, forming neutral
 salts, totrje  cases  of combinations, forming acids.
 In  the former case neutralization  is  produced,
 which  we readily admit inculcates the idea of the
 concurrence of both substances in producing the
 effect,; but  Mr.  Mitchell reasons from analogy,
 that acidity  is produced in the same manner;  and
 here is perceived an assumption that can be by no
 means admitted, which is, that if both  bodies, in
 onle chemical combination concur in producing a
 property generated, that this must be the case in
 the generation  of any other property in any other 
An Enquiry, He.             21
 combination.  But so far from believing this to be
 the case, it is our opinion when reasoning abstract-
 edly, that the properties generated by any compo-
 sition, may be referred with equal propriety to one
 as to both or all ingredients employed ;  there is
 nothing  in  the  nature  of the case, which would
 lead us to think otherwise;  and  we may add that
 this belief is not only reasonable and in the nature
 of things, but that it is completely consonant with
 fact: we have  said before that  the  properties
 generated in any chemical  union  must  neces-
 sarily be referred either to both or all the constit-
 uents taken collectively, or to one of them alone;
how can  we reasonably say that  one of the possi-
ble ways must always take place, to  the exclusion
 of the other ; besides,  the circumstances, from
 their nature, attendant on any chemical union, will
inform us when  the changes are produced  by the
joint action of both, or  whether  the new proper-
ties are to be entirely referred to  some one of the
 ingredients : for  instance,  in the formation of a
 salt a negative  property is generated; a proper-
 ty  seeming to  indicate both substances  to have
 advanced half way  in  producing the  effect; but
 in the formation of an acid, the  matter is com-
 pletely otherwise ; for there we have qualities ge-
 nerated,  obviously and decidedly of a positive na-
 ture ; neither is there any thing which inculcates
 the idea, that the substances have both concurred
 in producing the effect, nor that  any thing inter-
 mediate in properties has been formed.
                       D 
Q2            An Enquiry^ He.

   Thus we have rendered it probable thatboth cases
can exist; that in acids but one, that in salts both
ingredients  concur in producing  the respective
effects.  But as we have proved by  a certain
method to demonstration that oxygen alone is the
cause of acidity, a good way to test the rule of
reasoning,  upon which those conclusions  are
founded, would be to apply it to the case of a neu-
tral salt, to see to what  conclusion it  will there
lead us, as it respects the cause of the neutrality
—for  this purpose  we  shall  select for consi-
deration the  muriate of soda; now it is required
to find from what source this body  derives that
property called  neutrality; it  must necessarily
arise either from the  muriatic  acid or the soda,
or from both;  but it does not arise from the  mu-
riatic acid alone, for if it did, a salt should be  pro-
duced in all its combinations with other bodies,
whether they be similar or dissimilar, when they
unite in an indefinite proportion, which is not the
case, as the  consideration of the  nitro-muriatic
acid will abundantly prove ;  neither does it  arise
from the soda for exactly the same reason; there-
fore if the property generated arises neither from
the acid nor the alkali individually, it must neces-
sarily  arise from both—this is a negative deduc-
tion, but we  arrive at the same  conclusion, when
reasoning positively ;  thus, if the property gene-
rated arise from both, then either body will  not
be able to produce the effect when united to any
other dissimilar body,  which is  exactly the case ;
therefojp it does arise  from  both—or  we might 
               An Enquiry, He.            23

prove the same thing by supposing it did not arise
from both, which  would necessarily lead us into
m absurdity.  Thus it is perceived, that whether
we reason positively or negatively, or by a combi.
nation of both methods, we arrive  at  the same
conclusion.
 We shall conclude by enumerating some gene-
ral  propositions, demonstrated in, or  deduced
from, the foregoing views of the subject.
   1st. That the belief that hydrogen exists in all
ternary acids, as well as oxygen, does not invali-
date the opinion that  oxygen  is the principle of
acidity;  or in other words, we  need not reject
those  arguments  which make it  probable that
there exist but three elementary substances, from
a fear that they have a tendency  to subvert the
belief that oxygen  is that principle.
   2nd. That reasoning a priori, we have no just
grounds for concluding that the properties gene-
rated  in  any  chemical union should arise from
both or all its constituents, rather than either sepa-
rately, but that they  may arise in  either way ac-
cording to circumstances; and further that a care-
ful examination of  the phenomena attendant on
chemical  union must decide  whether  they  do
arise both ways, according to circumstances.
   3d.  That an attentive examination of chemical
combinations, as  completely  demonstrates that
they do arise in both ways according to circumstan-
ces, as the reasoning a priori)  that they  may. 
24            An Enquiry, &v.

   4th. That the belief in the reciprocity of chem-
ical action, is not inconsistent with the admission
of the two last propositions.
   5th. That those who believe in but three ele-
mentary substances, and that hydrogen is the base
of the muriatic acid, must necessarily  admit that
the reasonings  derived from the consideration of
the binary  acid  compounds, in proof of oxygen
being the principle of acidity, are as decisive and
certain, as  those  in  any proposition in Euclid,
inasmuch as they are as complete as the nature of
their belief will admit.
   6th. That those who do not believe that hy-
drogen is a constituent, either in all metals  or in
phosphorus, sulphur or carbon,  may render the
demonstration even more complete (if this indeed
be possible) only by applying the rule to every
one of the accession of binary acid compounds,
which a disbelief in that extensive agency of hy-
drogen  would  necessarily produce: among this
accession would be the five metallic acids, together
with  the  sulphuric phosphoric   and  carbonic
acids.
   7th. That those  who believe in this extensive
range of hydrogen,  but not in it, as the base of
the  muriatic acid,  must  admit,   in  case  it
should be clearly  demonstrated that it was the
base of that acid, that the arguments  which have
been  adduced  to prove oxygen the principle of
acidity are conclusive.
   8th. That the only method of proceeding to
attain a knowledge, of the  principle  of inflanv 
               An Enquiry, He.             25

mability,  is  by  treating  the  subject in  an
analogous manner to that by which we made evi-
dent the principle of acidity.
  And we hope to prove in a future communica-
tion that the supposition of any substance, being a
principle of inflammability, i.e. an only body which
will leave  its caloric and light in part or entirely,
to unite with other bodies, is only tenable  upon
an hypothesis, which will not be readily admitted;
and even then, we may add, the proof is not quite
complete, but as  we  said before, we beg leave to
lay  before the  gentlemen of the society  our pecu-
liar opinions on that head in a future essay. 
26   On the Prognostic Signs of the Weather*
                                           •j.
On the prognostic signs  of the  weather.   -By
  James Cutbush.  Professor of chemistry, He-
  rn St. John's College, Philadelphia.

  Meteorology, a branch of natural philosophy,
is important in many respects.  It interests man-
kind as it furnishes predictions of the change  of
weather.  Within a few years, many philosophers
have  turned  their attention to this subject, since
which,  various observations have been made.
The experiments and  remarks of De Luc, E>,e
Saussure, Jones,  Marshall and Kirwan afford  a
number  of facts in meteorology.  Observations
have been made by these and other gentlemen, on
different signs, which arise from a combination of
circumstances, in order to establish some general
rules respecting the changes of the weather.  Thus
we have animate and inanimate substances, as well
as the barometer, thermometer, hygrometer and
electrometer, as active instruments to accomplish
this end.   If these, as well as the  action of winds,
answer in their results, a correct datum is at once
established.  Although  inaccuracies  may  arise
from a multiplicity of circumstances,  and events
may occur contrary to expectations, yet upon the
whole, when these instruments and signs are pro-
perly  used, they must eventually lead to truth,
the grand desideratum in philosophical inquiries.
  As well as a correct application of the meteorolo-
gical instruments and bodies, as  we have already
remarked, the various states of the sky, the clouds 
    On the Prognostic Signs of the Weather.  27

the changes in the wind, &c. are essential in this
investigation.
   1. Prognostics by the spider, Hc....Mr. Disjon-
val,  an  adjutant-general in the Dutch service,
while a prisoner, made a variety of experiments and
observations on the spider, which  have shown
that they may be employed with  advantage in
meteorological inquiries.   His remark is, " that
spiders are particularly excellent as  prognostica-
tors of changes in the weather, being more certain
than the barometer, giving their indications a long-
er time before hand, and having this  advantage to
the lower class of people, that they cost nothing."
On the  common house spider he made the fol-
lowing remarks.   Against fine weather, it peeps
out its head, and stretches its legs out of its hole;
this the further the longer the fine weather will con-
tinue. Against bad weather, it retires farther back ;
and against very tempestuous weather it turns quite
round, showing nothing but its hinder parts to the
observer, thus acquainting him  with the approach-
ing change of the  weather.  At the commence-
ment  of fine weather, the  webb,  with  which  it
surrounds  its corner, is but of moderate extent;
if the fine weather will be lasting, it enlarges it to
two or three  inches; and  if it do  this  several
times repeatedly, we may be certain, that the wea-
ther will continue fine for some time.
   On the 22d of July 1795 Mr. D. foretold, from
the behaviour of his spiders, a fortnight before
hand, that the water of the Rhine would fall .so 
28  On the Prognostic Signs of the Weather.

as to render it passable by a bridge of boats; and
in this manner it was always passed.
  His observations on the general conduct of the
spiders in the winter season,  are  also important.
They are also prognosticators of approaching cold.
If frost and snow be coming on, they either seize
upon the webs already made, in which case obsti-
nate battles frequently ensue, or they make  new
ones, and labour diligently at them.
  Disjonval found, from  several attentive obser-
vations, that, from the first of the spiders putting
themselves in motion to the setting in of the frost,
nine days generally elapsed.   We have a striking
instance of the justice of this  observation in the
beginning of  February 1793.  The weather was
fine, warm, and there was no symptom of approach-
ing frost.  It might have been supposed thatfires
would be no longer required; but on the 4th of
February Mr. Disjonval announced, that a great
alteration in the  weather would ensue, as,  besides
other remarks of a similar kind, he had seen three
spiders webs one over another, in a place where
there was not one  the preceding evening.   On
the 9th of February there was ice, and by the 13th
all the canals were frozen over.  It was now pro-
bable, that with  the breaking up  of the frost the
winter would terminate.  This was the opinion of
Mr. Disjonval himself:  and he felt no small satis-
faction, in having been able to foretell the freezing
of the canals to a whole town, when such a circum-
stance was least expected.  A complete thaw in
fact came on; but  on a sudden he observed, con- 
On the Prognostic Signs of the Weather.  29
 trary to all expectation, a general bustle among his
 spiders on the  last day of February.  They ran
 backwards and forwards, began to spin webs dili-
 gently, and attacked one another.  Hence he in-
 ferred, that some remarkable change was taking
 place;  and that very dry weather at least, if not
 very cold would ensue.  This conjecture he an-
 nounced to the principal bookseller  in the town,
 and through him to the public.  Two days  after
 it rained, which seemed no way favourable to his
 prognostication ; and this rain continued for five
 days, so that the validity of his prediction appear-
 ed daily more questionable.  Still, however, atten-
 tive to  the  proceedings of his  spiders, he wrote
 every day  to the same bookseller, telling him he
 continued firm in the persuasion of the approach
 of cold and dry weather.   On the 8th of March
 it blew hard; on  the  9th it snowed;  and on the
 10th the frost was so sharp, that all the canals were
 frozen over again.
   The greatest and  most striking instance of the
 importance of these observations, and the depen-
 dence that may be  placed on predictions respect-
 ing  the weather from them, is  the  conquest of
 Holland by the French in  the winter of 1794-5.
 Disjonval's keeper was inclined to the patriotic par-
 ty, and in consquence treated  his  prisoner with
 less strictness.   Through  his  means  Disjonval
 gave notice to the patriots, that a hard  Winter
 would ensue, which would render all the rivers and
canals passable on the ice. The taking of the town
 bv the French afforded him the only hopes of be-
                       E 
30   On the Prognostic Signs of the Weather.

ing emancipated from his  long imprisonment:  it
may be supposed, therefore, that he observed his
spiders with the utmost care and attention.  In the
beginning of December he  heard, to  his great
alarm, that the people  talked  of  a capitulation,
which would have annihilated his hopes at once.
He used every means in his power, to make known,
that, from the operation of his spiders, a very se-
vere frost would inevitably come on, and this with-
in a fortnight at farthest.   The people gave credit
to his prediction, did not  capitulate, and on the
29th of December, the frost was so hard, that the
French were able to  pass  the wall.  The  aristo-
cratic party flattered  themselves, notwithstanding,
that the frost would soon break up, as on the 12th
of January the water rose, and was turbid, which
was considered as a  certain indication of a thaw,
Disjonval in the mean time, wrote from his prison
to  the editor of the  Utrecht gazette,  that, before
three days had  elapsed, a more  severe cold than
the former  would take  place.  On this occasion
the spiders proved incomparably better prophets
than the turbid water; on the 14th of January the
wind rose, on the 15th it froze, and  on the  16th
the French entered Utrecht; thus the prisoner re*
 gained his liberty.
   He continued carefully to observe the spiders he
could find, in order  to give  the  French general
 fresh information, which was of such importance
 to him in this daring enterprize.
   On the 20th of January a sudden thaw came on,
 The general was alarmed for the fate of an army 
On the Prognostic Signs of the Weather.  31
 of an hundred thousandmen, witha train of artillery,
 and began to think of a speedy retreat.   But Dis-
 jonval  had recourse to his spiders, and they fore-
 told frost.  He sent a couple of these little pro-
 phets to the French general: they were credited,
 their prophesies  were fulfilled, and the French
 conquered Holland.
   Such a  striking circumstance induced  the
 French executive directory to institute  an inquiry
 into this branch of knowledge ; observations will
 be  made,  most probably  in  other countries;
 and these odious spiders may be found of the  great-
 est importance, in meteorology, and consequently
 of great use in common life.
   Besides what we have already said on the sub-
 ject of the spiders, the leech has been found  to an-
 swer the same purpose; namely, its   rising  or
 falling in the bottle as  indications  of particular
 changes ; but  how  far observations drawn from
 this circumstance  are true, remains to be decided.
 Amongst the general or common pragnostics  of
 the weather, we may reckon  such as are derived
 from birds, beasts, insects, reptiles, and plants, to
 which might be  added  great part of the  wood
 work in houses, as doors, windows, window shut-
 ters, &c.
   Birds in general retain in the quill part of their
feathers, a quantity of oil, which, when  they feel
an extraordinary degree of moisture in the atmos-
 phere, they express by means of their  bills, and
distribute it over their feathers to secure their bo-
dies against the effects of an approaching shower. 
32   On the Prognostic Signs of the Weather.

  Swallows,  in  pursuit of flies and  insects,  or
which they prey, keep near the earth in wet wea-
ther, and  in dry weather  from the same cause,
they fly much higher.
  Domestic animals, as cows and sheep, but par-
ticularly  the latter, on the approach of rain, feed
with great avidity in the open field, and retire near
the  trees  and hedges as soon as they are satisfied.
In fine weather, they graze and lounge about eat-
ing and resting  alternately,  with apparent  indif-
ference.
  The pimpernal, commonly called the peep-a-
day, or shepherds weather glass, closes its  leves
before rain; and the down of the dandelion is much
affected by moisture.
  All wood, even the hardest and most solid, swells
in moist  weather, the vapours insinuating them-
selves into the pores of the trees, and also into the
wood work of houses.
  Insects and reptiles of all  kinds, seek or  avoid
rain, according to their respective habits, by these
means giving notice of every change of weather.
  Dr. Manners informs me, that when the tree frogs
are observed to croak unusually, and the swine to
prepare for themselves beds, by carrying straw and
and other articles in their mouths, rain and stormy
weather is always to be apprehended.  This effect,
Dr. Manners has often witnessed.   There  are a
number  of signs,  in  use among  the  peasantry,
arising from the different habits of animals, that
are certain prognostics of the weather. 
   On the Prognostic Signs of the Weather.  33


   Sect. 2.  Prognostics by the Barometer.

  Many experiments and observations have been
made with this instrument, not only as connected
with meteorology, but also in a mathematical view,
as in ascertaining the heighth of mountains, &c.
  The variations in the barometer in different cli-
mates, as for instance, as we go to, or recede from
the  equator, have  occasioned  some  inaccuracies
on the subject.   The countries, however, that are
situated  about the  equator, are subject  to  the
changes of the weather, though it is more constant
there, than  in the temperate  climates: there are
changes there of humidity and dryness, rains  and
fair weather, storms and tempests, much more  vio-
lent than with us.
  Mr. Dalton has given the following general rules
and observations, for judging  of the weather.
  1.  The barometer is the highest of all during a
long frost, and generally rises with a N. E. wind;
it is lowest  during  a  thaw following  a long
frost, and is  often brought down  by a S. W. wind.
  2.  When nearest the high extreme for the  sea-
son of the year, there is very  little probability of
immediate rain.
  3.  When the barometer is  low  for the season,
there is seldom a great night of rain, though a fair
day in such a case is rare.   The general  tenor of
the weather  at such times is short, heavy, and sud-
den  showers, with squalls of wind from the S. W.
the W. orN.  W. 
34   On the Prognostic Signs of the Weather.
  4. In summer, after a long continuance of fair
weather, with the barometer high,  it often falls
gradually, and for one, two, or more days, before
there is much appearance of rain.  If the fall be
sudden and great for the season, it will probably
be followed by thunder.
  5. When the appearances of the sky are very
promising for fine weather, and the barometer, at
the same time low, it may be depended upon that
the appearances will not remain such long.  On
these occasions, the face of the sky  changes very
suddenly.
  6. Very dark and dense clounds pass  over,
when  the  barometer is high, without rain ; but
when the barometer is low, it sometimes rains al-
most without any appearance of clouds.
  7. All appearances  being the same, the higher
the barometer is, the  greater is the probability of
fair weather.
  8. Thunder is generally preceeded by hot wea-
ther, and followed by cold and showery weather.
  9. A sudden and extreme change of the tempe-
rature of the atmosphere, either from heat to cold,
or cold to heat, is generally followed by rain with-
in 24 hours.
  10.  In winter, or during  a frost, if it begin to
snow, the temperature of the air generally rises to
32 degrees, and  continues there while the  snow
falls;  after which, if the weather clear up, expect
a severe cold.
  11. The aurora borealis is a  prognostic of fair
weather. 
    On the Prognostic Signs of the Weather.   35

  The  changes which  take place in the atmos-
phere are  principally marked  by the rising  and
falling of the barometer, which apparently is caus-
ed by heat and cold, the hands with which nature
performs  her  meteorological operations: by the
former the atmosphere is rarified, and consequent-
ly becomes light; by the latter it is condenced and
consequently  becomes heavy.   Hence  probably
the old remark, that a storm generally follows a
calm ; for during a calm the air i& rarified and ex-
panded,  and the cold air will rush  forward  in a
strong current to restore the equilibrium, and ne-
cessarily produce what  is  called a gale of wind,
the violence of which also will be in proportion to
the degree of the preceeding rarefaction of the at-
mosphere.
   For these reasons, the barometer falls suddenly
whilst the air  is expanded  before a  gale of wind,
and rises  again gradually as the  condensed air re-
turns, and the gale in like manner by degrees sub-
sides.
   It must, however, be observed, that an extraor-
dinary fall of the mercury will sometimes  take
place in summer, previous to heavy showers  of
rain,  particularly if attended with heavy thunder,
and lightning; but in spring, autumn and winter,
the sudden descent of the barometer indicates prin-
cipally  violent  wind.   Upon these  principles
likewise we may account for the rise and fall of the
barometer in  different zones.   In the torrid zone;
particularly at St. Helena, and the Islands of the
Pacific ocean, it seldom varies more than three 
 36   On the Prognostic Sigtu of the Weather.

 tenths; at Madras about five tenths ;  in the south
 of Europe not more than an inch and two tenths;
 in England it varies two inches and  a  half; in
 America about the same ; and in Petersburg three
 inches four tenths.
   The following observations of Mr. Patrick, on
 the application and use of the barometer,  in mete-
 orological inquiries, may be found useful:
   1. The rising of the mercury presages, in gene-
 ral,  fair weather ;  and its falling foul weather, as
 rain, snow, high winds, and storms.
   2. In very hot weather, the fall of the  mercury
 indicates thunder.
   3. In winter die rising presages frost; and in
 frosty weather, if the mercury  falls three or four
 divisions, there will certainly follow a  thaw,  but
 in a coutinued frost, if  the mercury rises, it  will
 certainly snow.
   4. When foul  weather happens soon  after the
 falling of the mercury, expect but little of it,  and
 on the contrary expect but little fair weather, when
 it proves fair shortly after the mercury has risen.
   5. In foul  weather,  when the mercury rises
 much and high, and so continues for two  or three
 days before the foul weather is quite over, then
 expect a continuance of fair weather to follow.
   6. In fair weather when the mercury falls much
 and  low, and thus continues two or three days be-
 fore  the rain  comes, then  expect a great  deal of
 wet, and probably high winds.
   7. The unsettled motion of the mercury  denotes
uncertain and changeable weather. 
    On the Prognostic Signs of the Weather.  37

   But to these remarks may be added,, that,  when
the barometer suddenly falls two or three tenths,
without any material alteration in the thermometer,
and the hygrometer is not  much turned towards
moist, a violent gale of wind may be expected.
   When the hygrometer inclines towards moist,
with only a trifling wind; and when the barometer
falls considerably, and the hygrometer turns much
towards  moist,  the thermometer remaining sta-
tionary, and rather  inclined to rise than fall, both
violent  wind and rain are likely to follow in the
course of a few hours.
   Owing  to  a misapplication of the barometer,
and frequently from an imperfection in the instru-
ment itself, errors may frequently occur. Accord-
ing to the following rules, several of these objec-
tions may  be  obviated.  It will then instruct the
farmer, with  certainty  when  to  hasten  and
when to  delay his work;  it  will  direct  the
mariner  when  to  prepare  against  the storm, or
the tempest, and inform him when he  may take
his rest with  security: it will teach the traveller
how to clothe himself for his journey.   In short,
it will not only discover the approach of rain, and
the return of fair weather, but will also enable the
observer to determine when either will be of Jong
or short continuance.
  1st. In making your observations on the baro-
meter, pay no regard to the words  engraved on
the plate, but  fix your attention  on  the moving
index, which you will do right to regulate very
frequently.
                      F 
38   On the Prognostic Signs of the Weather.

  2d. The mercury is always lowest in fine wea-
ther, especially if accompanied with rain.
  3d. It is always highest when the wind is at east
or north east, particularly if not strong.
  4th. It is high in calm frosty weather.
  5th. If it sink in frosty weather, a thaw of snow
always follows.
  6th. It sinks during violent winds.
  7th. When the mercury rises fair weather is ap-
proaching.
  8th. When it sinks, foul weather may be ex-
pected.
  9th. When the  weather  suddenly changes from
foul to fair, upon the first rise of the mercury, or
from foul to fair, upon its first sinking, such wea-
ther will not continue long.
  10th.  If in wet weather the mercury gradually
rises far about two days before the change, a con-
tinuance of fair weather may be expected.
   11th.  If it  gradually sinks for about five days
during fair weather, a  continuance of wet  gene-
rally follows.
  12th. When the  mercury  is  stationary,  whe-
ther high or low, a  continuance  of the weather,
such as it then is, may be expected.
  13th.  If you are desirous of  ascertaining the
weather for a day, or a few hours, it will be ne-
cessary to  inspect very accurately the surface of
the mercury ;  if it be remarkably convex or round,
it affords a  strong presumption of fair weather. If,
on  the contrary, it be very concave, or hollow, it
implies almost immediate rain. 
    On the Prognostic Signs of the Weather.  39


 Sect. hi.  Prognostications with the thermome-
   ter either alone or with other instruments.

   The thermometer is important as a meteorologi-
 cal instrument for various  reasons.  Its use is to
 ascertain  the variations of temperature.  While
 this instrument is  so employed, the hygrometer* is
 used to ascertain the quantity of moisture, and the
 electrometer to shew that of electricity which pre-
 vails in the atmosphere.
   From the thermometer we can ascertain, in win-
 ter, when  the cold diminishes rapidly, the coming
 of rain ; and in summer, by a sudden rise of the
 mercury the same result.
   If the air in  foggy weather becomes hotter by
 the action of the suns rays, the fog generally  dissi-
 pates, and the air remains serene : but if the  baro-
 meter fall, and the cliange of temperature (indicated
 by the thermometer) be from a south or a  south
 west wind,  the fog  rises and forms  itself into
 clouds, and its ascension  is  generally a sign of
 rain.        *
   When the barometer remains high and stationa-
 ry, the natural and factitious hygrometers indicate
dry air, the canopy of the sky lofty, and the  wind
north easterly, we may uniformly  expect settled
fair weather ; while a light and moist atmosphere,
 the canopy of the sky low, and a south west wind,
 certainly portend a wet season. 
40  On the Prognostic Signs of the Weather.


 SEGt. 4.   Indications  of the weather  by the
    clouds.

   A rain  tow in the morning  is said to be the
shepherds warning,  but a rain bow at night is the
shepherds delight.   This principle  may  be cor-
rect on philosophical principles : for if the clouds
to the westward in the  morning  are  saturated
with moisture, which they must be to produce a
rain bow, these clouds proceeding  from W. to-
wards  E. may bring rain; whereas, on the con-
trary, when the sun sets perfectly  clear,  and the
clouds to the eastward are moist, it is a proof that
the wet clouds are past, with a westerly wind, and
the shepherd therefore, may reasonably expect fine
weather on the following day.
   When it rains with an  east wind, it  probably
will rain 24 hours.  The weather generally clears
at noon,  but when it rains at mid-day, it  seldom
clears again till sun set.
  The air, when dry and warm, continues to abate
and retain the moisture continually evaporated from
tne earth ; as therefore the sun advances towards
the meridian, and for an hour or two afterwards,
he dries and warms the air ; and consequently the
rain is likely to cease at that time.   But  if there
should be so much water in the atmosphere, that
the heat of the sun is not sufficient to produce these
effects, in that case the rain will probably continue
some hours longer.. From the appearance of the
clouds, the kind of weather to be expected may be 
    On the Prognostic Signs of the Weather.   41

known. The following facts may, therefore, prove
useful :
  When the clouds are formed like fleeces deep
and dense towards the middle,  and very white
edges, with a bright blue sky about them, they ge-
nerally soon fall in hail,  snow, or in hasty showers
of rain.
  There is  no sign of rain more certain than two
different currents of clouds, especially if the under-
most fly fast before the wind ; when this happens
in summer, there is seldom wind at the time, and
thunder generally follows.  In winter the light va-
por, or scud as the sailors call it, often comes ra-
pidly against the wind, and a gale is soon after to
be expected.
  The transparency of the air is to the inhabitants
of the Alps one of the most certain  signs of rain;
when the distant objects  appear distinct and well
defined, when the sky is of a deep blue, they con-
sider rain as near at hand, though no other sign ap-
pears.  I have been informed by a gentleman, to
whom I am  under obligations for  other observa-
tions, that this sign, from the transparency of the
air is by no means local, but is often observed, that
in such a state of the air, the sailors say the land,
or some other object looms near, and expect bad
Weather.
   When the sky, in a rainy season, is tinged with
a sea-green  colour, particularly near the horizon,
when it  ought to be blue, the rain will continue
 and increase.  If it be of a deep dead blue, it will 
  42  On the Prognostic Signs of the Weather.
  be showery: this  is more particularly found to
  hold true near the  sea coast.
    Clouds of a  similar appearance produce thun-
  der in summer, and snow in winter;  such clouds
  are broken, and irregular shaped, heaped one on
 another,  and from their uncommon density pro-
 ject towards the earth.
    After a thunder  storm, when it  has been of con-
 siderable duration, the wind generally, if not al-
 ways, veers to  the quarter from whence the first
 clap proceeded.
    A close sultry day, the current  of air scarcely
 perceptible, is often succeeded  by a  change of
 wind.
    The wind shifting  from point  to  point round
 the compass,generally denotes rain. If after a con-
 tinued rain  from a muddy sky, the horizon appear
 lighter in any quarter, expect the wind from that
 quarter.
   Some  further remarks respecting the winds,
 may be interesting  in a meteorological view.
   Violent winds generally abate towards sun set;
 for, if we admit that wind is only  a current of air
 put in motion by the rarefaction of the atmosphere
 in some  particular place, and that  this current of
 air is moving  towards the rarefaction to restore
 the equilibrium, we must suppose,  that as the  sun
declines the  rarefaction will diminish, and conse-
quently the  velocity of the wind decrease.   But
this observation, in  my  opinion, rather applies to
the temperate than  to  the  torrid  zone; for  in 
   On the Prognostic Signs of the  Weather.  43

whirlwinds and hurricanes the contrary may often
occur.
  When the wind follows the course of the sun,
it is generally attended with  fair weather.  This
frequent and regular change of the wind, which is
never more  than a moderate  breeze, proves that
there is no point of considerable rarefaetion near,
and  therefore, the current of air follows immedi-
ately the sun's course: it always happens in sum-
mer,  but  very seldom when the sun's meridian
altitude is less than 40 degrees.
  It is a well known fact, that before rain, particu-
ly in summer, a strong smell is perceived from
drains and common sewers, as well as from every
other body,  emitting a great  quantity of effluvia.
During fair weather, even in  the summer, the at-
mosphere readily absorbs all  the vapours and ex-
halations from the earth  until it is completely sa-
turated, and consequently the effluvia from the bo-
dies which emit  them, will then be confined and
ascend in a narrow compass,  like  the smoke  of a
chimney in  dry weather,  almost  perpendicularly ;
but when the  air is saturated with moisture, and
becomes rarefied and expanded, as it always does
before rain, the volume of air containing the efflu-
via will be extended  horizontally, and diverge
from these different bodies as from a centre,  and
will  be sensibly perceived on all sides, but  will of
course be most perceptible on  that to which the
current of air  or wind moves. 
 44  On the Prognostic Signs of the Weather.

 Sect. 5.  Of the  instruments used to ascertain
           moisture in the atmosphere.

   The hygrometer  is an instrument intended to
discover the moisture contained in the atmosphere.
The substances affected  by moisture  are nume-
rous : thus wood expands  by moisture and con-
tracts by dryness ; on the contrary, cord, catgut,
&c« contract by moisture and lengthen by dryness,
consequently, the contraction and  expansion of
these bodies indicate different states of the air with
respect to moisture.  The twisted beard of a wild
oat, with a small index fixed to it, moveable against
a scale makes a very good hygrometer.  Mr. De
Luc has shown  that whale bone and box, cut
across this fibre, answers extremely well.
   Hvgroscopic substances  are of three distinct
kinds.   1st.   Those  that seize  on   the  water
of vapour by  an affinity  for that liquid ; among
these are acids, alkalies (all deliquescent salts) and
and some earthy substances.  2d. Those that im-
bibe the water, by the tendency it  has to propa-
gate itself in capillary pores,  but from their nature
receive no sensible increase  of  bulk by its intro-
duction ; such as porous stones.  3d. Those that,
imbibing a certain quantity  of water, are thereby
expanded, such as most of the vegetable and ani-
mal substances.   M. De  Luc, by a long series of
experiments, to which I  must  refer you, shows,
that the substances of the last  class are the only 
    On the Prognostic Signs of the Weather.   45

 ones proper for hygrometers.  From time imme-
 morial, the effects of moisture have been consider-
 ed as prognostics of the weather, as is evident by
 the confidence the housewife places in her salt box,
 the carter in his whip leather thong, and the sailor
 in his shrouds.
   The application of the hygroscopic substances
 already mentioned, to  the purposes of meteorolo-
 gical observation, is affected by various contrivan-
 ces,  some of which are  extremely  simple, and
 others again complicated.   The weather gage, as
 it is termed,  sold by the toy sellers, although  not
 intended to tell the degree  of moisture, as is the
 true hygrometer, is at once an instrument of utili-
 ty and elegance.

 Sect.  4.  Of the  instrument  used to  discover
              electricity in the air.

   With respect to atmospherical electricity, as
 connected with this subject, little  need be said.
 From experiments made with Mr. Bennet's elec-
 trometer, it appears, that particular states of the at-
 mosphere, influence certain changes so considera-
bly, that electricity would seem to be  a  primary
agent in many of these changes.    In stormy wea-
ther we see the electricity strong, then null, and in
a moment after arise to its former state :  one in-
stant, vitreous ;  the next,  resinous.   M.  de Sau-
sure says, that he has seen these changes  succeed
with such rapidity, that he had not time to note
                        G 
46   On the Prognostic Signs of the Weather.
them down.   When  rain falls without a  storm,
these changes are not so sudden ;  they are how-
ever, very irregular.   Rain or  snow almost  uni-
formly gives vitreous  electricity.   Foggy wea-
ther produces the greater quantity of electricity.
  Experiments, therefore, with the electrometer
added to those of the barometer, thermometer, and
hygrometer will afford correct  deductions. 
EXPERIMENTS AND OBSERVATIONS
 On the effect of light on vegetables and upon the
   physiology of leaves, By John Ma n n e r s, M. D.
   of Philadelphia.  Honorary member of the Me-
   dical, Medical Lyceum, and Columbian Chemi-
   cal Societies of Philadelphia; Member  of the
   Philadelphia Agricultural,  and Linnean Socie-
   ties,  Fellow of the Academy  of Natural Scien-
   ces. He.

   AFTER the memorable discovery of oxygen
gas or de phlogisticated air, that sine qua  non of
combustion,  acidification and  respiration,  by  the
celebrated Dr. Priestley on the 1st. of August 1774,
various  methods were discovered by which oxy-
gen gas might be obtained.
   Dr. Priestley obtained it by exposing the black
oxyde of Manganese per se in an iron retort to an
obsure red heat and receiving  the  gas  over the
Pneumatico-chemical apparatus, of which he was
the inventor.  Though Dr. Mayow first invented
the method of collecting gasses over water, which
was afterwards  improved  by  Dr.  Hales,  Dr.
Brownrigg and Mr. Cavendish.
   This  was  the method of obtaining oxygen gas
preferred by Dr. Woodhouse. 
 48     Experiments and Observations, He.
   Scheele,  who procured  it shortly after  Dr.
 Priestley,  added  vo  the black  oxide,  sulphuric
 acid, which renders so high a degree of heat un-
 necessary.   By which a glass, may be substituted
 for an iron retort.  1400 cubic inches of oxygen
 gas may be obtained from one pound of the black
 oxyde;  but  always  contaminated  with a small
 portion of carbonic acid and nitrogen gas. It may
 be freed from the former by lime water, but from
 the latter it cannot be freed by any known process.
   The oxydes of lead, particularly minium  and
 litharge, afford it abundantly when either exposed
 to heat, per se or with the  addition of sulphuric
 acid. But like that obtained from manganese mix-
 ed with carbonic acid and azote or (as M. Chaptal
 has more properly called it) nitrogen.
   The oxydes of mercury,  particularly the red
precipitate per se, afford it in large quantity.   But
 as M. Chaptal  has proved holding mercuiy in so-
 lution, as  he  found the oxygen obtained from
 mercury when inhaled into the  lungs for medical
purposes, excite Ptyalism.   He also, by exposing
it to extreme  condensation  by cold,  procured a
mercurial oxyde.   According to him, every ounce
of mercury yields one pint of oxygen gas.
   In fact almost all the oxydes of metals (except
the alkaline and earthly oxydes lately discovered
by Sir H. Davy) may  be so treated  as to afford
oxygen.
   The nitrate of potash when exposed to heat in
a retort affords  oxygen gas nearly in a state of pu-
rity containing only a minute portion of azote. One 
       Experiments and Observations, He.    49
             , *
pound of this salt is  said to yield 1200 cubic in-
ches.
   The oxymuriate of. Pot ash affords  it in large
quantity, and in a state of great purity.
 Very pure oxygen gas may he obtained from the
large extremity of the egg.  For an account of
which see Dr. Coxe's Inaugural Dissertation.
   Different  acids,  when exposed to  light  emit
oxygen, as the nitric, oxymuriatic, &c. see Mrs.
Fulhame on combustion.
   Different metallic salts as muriate of silver, nitrat
of silver, muriate of gold, muriate of platina, He.
when exposed to the rays of the sun become redu-
ced and, as M. Berthollet first observed, emit oxy-
gen gas.   And this effect is not produced equally
by all the different coloured rays.  After Sir Isaac
Newton decomposed the rays of light  with the
prism into the seven primary colours, red, orange,
yellow, green, blue, indigo  and violet, Dr. Hooke
demonstrated by those simple and well known ex-
periments of placing different coloured pieces  of
cloth in the snow and marking the different degrees
they sank, that the different coloured rays, possess-
ed different heating powers.  These experiments
were afterwards repeated by Dr. Franklin, and still
more lately in a  more simple way by Mr. Davy.
But  the philosophic world are chiefly  indebted to
Dr.  Herschell, whose  experiments  were  after-
wards repeated and confirmed by sir Henry Engle-
fieid, for a complete division of the solar spectrum
into calorific .,r.d colorific rays. Scheelediscover-
ed that the reduction of metals takes place more 
50    Experiments and Observations, He.
quickly in the violet  ray.   Ana* Dr. Wollas-
ton, Richter, and Bockmann investigated the sub-
ject still further and provejl that the reduction is
even more rapid beyond the violet extremity of
the prismatic spectrum and  consequently  disco-
vered deoxydizing rays.
  The abbe Fontana found  certain insects when
exposed to the rays of the sun emit oxygen. And
the green matter which Dr .Priestley placed among
the conferva, which Mr. Senneber supposed  the
conferver cespitosafilis rectis undique divergentibus
Halleri, and which  Dr. Ingenhousz  supposed a
mass of animalcula, when exposed to the sun af-
ford vital air in large quantity.
  This fact was first discovered  by Dr. Priestley
as we are informed by Dr.  Darwin in the follow-
lines:

  Sylphs !  ybu, retiring to sequester'd bowers,
  Where oft your Priestley woos your airy powers,
  On noiseless step or quivering pinion glide,
  As sits the Sage with Science by his side  ;
  To his charm'd eye in gay  undress appear,
  Or pour your secrets on his raptured ear,
  How nitrous Gas, from iron ingots driven,
  Drinks with red lips the purest breath of heaven;
  How wile Confervera, from its tender hair,
  Gives in bright bubbles empyrean air;
  The crystal floods phlogistic ores calcine,
  And the pure ether marries with the Mine.
                 Botanic Garden, Canto 4, 179. 
       Experiments and Observations, He.    51

   It would be foreign to the present subject to en-
ter particularly into the natural history  of these
confervse, or the interesting speculations of Dr.
Priestley, Dr. Girtanner, Dr. Ingenhousz,Dr. Dar-
win, Mr. Buffon, my father-in-lawprofessor Cooper,
and other philosophers respecting their origin, and
the theory of equivocal generation, or the doctrine
of organic particles. But certainly the ingenious and
numerous experiments of Mr. Buffon (Nat. Hist.
v. 2d. p. 148, sect. 1. 8vo. Ed.) and the interesting
experiments of Reaumur, Ingenhousz, Ellis and
other naturalists have never been refuted, and de-
serve much more of the attention of philosophers
than they receive at the present day.   As the pro-
duction of mushrooms from horse dung, the confer-
va from stagnant water, microscopic animals from
veal broth boiled in a  vessel hermetically sealled,
&c. can only be satisfactorily accounted for by the
doctrine of organic particles.  Dr. Darwin the phi-
losopher and poet has expressed his opinion on this
subject with equal poetic grandeur and philosophic
elegance.

   Thus the tall Oak, the giant of the wood,
   Which bears Britannia's thunders on the flood ;
   The  Whale, unmeasured monster of the main,
   The  lordly Lion, monarch of the plain,
   The  Eagle, soaring  in the realms of air,
   Whose eye undazzled drinks the solar glare,
   Imperious Man, who rules the bestial  croud,
   Of language, reason and reflection proud,
   With brow erect, who scoms this earthy sod,
   And styles himself, the image of his. God; 
 52    Experiments and Observations, He.

   Arose from rudiments of form and sense,
   An embryon point, or microscopic Ens !
             Temple of Nature, Canto  1.  303.

   Dr. Priestley, Dr. Ingenhousz  and Sennebier
 discovered nearlyabout the same time that the green
 leaves of vegetables when exposed in a glass ves-
 sel filled with, and inverted over water emit oxy-
 gen gas, and this fact is  detailed by every author
 who  has  written professedly on either  chemis-
 try, or vegetable physiology.
   Various explanations of the rationale of the phe-
 nomena attending it have been given by  different
 philosophers.
   It has generally been supposed that the water is
 decomposed, that the oxygen of the water unites
 with the heat and  light of the rays of the  sun,
 while  the   Hydrogen  of   the water,   unites
 with the vegetable leaves, for their support.  But
 the scientific Dr. Woodhouse in a course of well
 conducted experiments proved that the  water is
 in no instance decomposed by the vegetable leaves,
 and that the oxygen gas is the product of the de-
 composition of carbonic acid with which the wa-
 ter is impregnated.   I have repeated, multiplied
 and varied the experiments of our respected pro-
 fessor, and satisfied myself of their correctness.
 I shall therefore mention some few of those which
 I think most conclusive, as to enumerate the whole
 would be tedious and not interesting.  I put some
leaves in a vessel  filled with, and inverted over wa-
ter ; gas  began  immediately to ascend.  I took 
      Experiments and Observations. He.     53

«ut the same leaves and  put them in lime water,
but not a particle of gas was obtained  in this ex-
periment.  I took out the leaves, washed them
and put  them in water, and gas was immediately
disengaged from them.
   But lest the lime water either, by  its stimulus
or  chemical properties, might destroy the  power
of the leaves  to  decompose water, I placed them
in distilled water, and in water which had been
boiled two or three hours : but in neither of these
experiments  did I obtain any  gas.   I then im-
pregnated water slightly with carbonic acid, and
placed leaves in it,  and now gas was procured
more abundantly than in any of my  former ex-
periments.*
   How wise the economy of nature, in thus form-
ing the  animal   and vegetable kingdoms recipro-
cally and essentially to serve each other ! And how
beautifully does it exemplify the harmony of the
material  world! That while the animal kingdom
by respiration consumes oxygen gas and converts
it into carbonic acid, (not to mention the immense
quantity of oxygen converted into fixed air by com-
bustion,) the vegetable kingdom  from carbonic
acid generated  by respiration, combustion, fer-
mentation and  all its numerous sources,  by the
agency of light  manufactures the vast mass of
atmospheric oxygen, and thus restores the equili-
brium of nature.

  * See some interesting1 remarks on this subject, by Professor
Outbush, in his Philosophy of Experimental Chemistry, vol. 1.
H 
54     Experiments and Obseruations, He.
" When Mom escorted by the dancing Hours,
O'er the bright plains her dewy lustre showers,
Till from her sable chariot Eve serene.
Drops the dark curtain o'er the brilliant scene,
You form with chemic hands, the airy surge,
Mix with broad vans, with shadowy trident  urge.
Sylphs! lrom each sun-bright leaf, that twinkling
  shakes,
O'er Earth's green lap, or shoots amid her lakes.
Your playful bands with simpering lips invite,
And wed the enamour'd Oxygen to Light.
Round their white necks with fingers interwove,
Cling the fond Pair with unabating love.
Hand link'd in hand  on buoyant step they rise,
And soar and glisten in unclouded skies.
Whence in bright floods the Vital Air expands,
And with concentric  spheres involves the lands;
Pervades the swarming seas and heaving earths,
Where teeming Nature broods her myriad births;
Fills the fine lungs of all that breathe or bud,
Warms the new heart and dyes the gushing blood:
With Life's first spark inspires the organic frame,
And as it wastes renews the subtile flame.
         Darwin's Botanic Garden, Canto iv. 25.

   In repeating these experiments I observed a phe-
nomenon which I had no where seen mentioned in
oither botanical or chemical authors.  I perceived all
the gas to be disengaged from the inferior surface
fpagina inferior J of the leaf. This surprized me as
I was better prepared to meet a contrary result:
Dr. Darwin tells us  in his Phytologia that the su- 
      Experiments and Observaiions, He.     55
perior surface of the leaf, performs the pulmonary
function  and  that  if  this  surface of  the leaf
be covered with a coat of oil or  varnish it dies.
The experiments of M.  Bonnet would seem to
prove the same.  And Mr. Parke in his chemical
catechism expressly says the gas is only  disen-
gaged from the upper surface of the leaf.   I men-
tioned the occurrence to Dr. Barton whose exten-
sive knowledge of botany, as well as chemistry,
would enable him  to  give me more satisfactory
information on the subject.  But he was no less
surprised than myself.
   I was  therefore induced  to   repeat my  ex-
periments ; but always with  the  same result.   I
took two leaves of the prunus cerasus, or  com-
mon cherry, which were  the  leaves with which I
had made all my former experiments and placed
the superior disk of the one,  and the inferior disk
«f the other leaf under water in  an inverted bell
glass to tlfe direct rays of the sun; but the result
was precisely the same.  These experiments were
seen by  Dr.  Barton.    I  then repeated the
 experiments  of M. Bonnet and Dr. Darwin by
coating  different  surfaces  of  different  leaves,
but with a different result from those philosophers.
All those leaves whose upper surfaces were coat-
ed with  oil, remained  healthy   and  vigorous;
while those whose under surfaces were coated, died
 in two or three days.  These specimens  I had
 also the  pleasure  of showing to Dr, Barton who 
56     Experiments and Observations, He.
requested I would pursue the subject further, and
was so kind as 10 give me access to any of the bo-
tanical specimens in his possession, I gladly availed
mvself of his liberality.   I  procured from him the
leaves of a variety of  different vegetables and ex-
posed them in water to  the rays of the sun.  But
here  I found a difference of result, some emitting
the gas from both surfaces, while others only from
the inferior page.  I took two leaves of the prunus
lauro cerasus and exposed them in different vessels
filled with  water ;  the  one  with the upper,  the
other with the  under surface to the sun ;  but in
both the gas was disengaged from the inferior page.
 I took two other leaves of the same vegetable and
 coated the upper surface of the one, and the under
 surface  of  the  other.  The  result was, that the
 one  whose  upper surface was coated  remained
 healthy  and  vigorous  after the other was dead.
 I have repeated and varied these experiments with
 the leaves of some species of MagnoliajPeach^nd
 the leaves of a variety of trees with the same result.
 But I have repeated them  with a  considerable
 number of the leaves  of  herbaceous  plants  and
 here in every instance with a different result,  the
 gas being disengaged either indiscriminately from
 both surfaces,  or else chiefly  from  the  upper.
 May not  this  explain the  difference  of result
 between my experiments and those of M.  Bonnet
 and Dr. Darwin ? probably they experimented
 with the leaves of herbaceous plants only,  while I
:■# 
      Experiments and Observations, He.     57
experimented with leaves of both trees and herba-
ceous plants.
  Upon  the whole I am  warranted to conclude,
as far as my experiments go, (though I acknow-
ledge they are not very conclusive) that fhe leaves
of trees and herbaceous plants perform the same
function  with different surfaces of their leaves. 
SPECULATIONS ON LIME.
 By Joel  B. Sutherland, M. D. Honorary
   member of the Columbian Chemical Society, and
   Fellow of the Academy of Natural Sciences.


     TO enumerate all the advantages, or disad-
 vantages to be derived from lime, is not my pre-
 sent object;  but only to call your attention, to cir-
 cumstances relative to lime, which are novel, and I
 hope not of an uninteresting  nature.  Lime for
 ages past, has been made use of in  the formation
 of mortar, a  cement  of great  importance to the
 world ; but although this cement is of such consi-
 derable  importance to the world at large, yet,  in
 certain instances, I think  it becomes highly pre-
judicial, not only to our houses, but to our con-
 stitutions, and that altogether on account of its in-
 correct formation.
  In general, pure sand loom, water and lime con-
 stitutes  this  valuable  cement: and when this is
the case, no disadvantages can arise from its use. 
Speculations on Lime.           59
But when lime i6 brought to this city which is im-
pregnated with the muriate of soda and  substitu-
ted in place of that which contains little or, none
of  that ingredient, the reverse is the exact state-
ment of the case; for the muriate of soda com-
bined with the sand when intimately mixed with
the other ingredients in mortar,  gives  so much
coldness to the mass, that during the whole  sum-
mer, the vapour, which  floats in the atmosphere,
is almost incessantly precipitated upon the  wall.
In confirmation of this I shall offer bnt a single
fact to your consideration, which I have no doubt
will substantiate what I have asserted.   A gentle-
man with whom I am very  intimate, found it ne-
cessary some years ago, to plaister anew a portion
of his house, on account of the innovation  made
with respect to the  regulations  of  the street  in
which he resided.
   In this case, the gentleman instead of procuring
the purest sand, purchased that species contain-
ing common salt, suspecting this was the  best on
account of its whiteish appearance.  But from that
time up to the present period, that portion of the
Wall formed by the muriated sand,  has  been pro-
fusely  sv?eating, (to use a common phrase)  while
the old  part of the wall produces little, or no fluid,
on account of its inferior temperature.
   From what  has  already  been said, it must be
very evident to a man of the narrowest mind, that
in choice of sand; that which contains the smallest
quantity of salt is most  assuredly the best.   But
before I come to a conclusion on this part of my 
 ^           Speculations on Lime.
 cubjectv I shall, offer a single conjecture to the
 Society.   What would be the effect, if we should
 plmster our cellars in toto with a mortar contain-
 ing a very large quantity  of common salt, might
 we not expect to obtain from them, ail the advan-
 tages of a spring house.  I shall now proceed  to
 say a few words upon another subject, in which
 lime is called into question.   Hens fed from the
 hand of a citizen of any populous town,'not un-
 frequently deposit their eggs, without a calcare-
 ous  covering.   And why ?  The people in gene-
 ral explain the fact, by saying  fat hens sometimes
 lay their  eggs without  shells.   This may satisfy
 the vulgar and incurious mind ; but one of a phi-
 losophic  nature, endeavours to explain  it  in a
 more rational manner.  In a city like this chickens
 do not obtain  a Quantum  sufficit of substances
 containing lime to form the shell.   This then is
 the plain  and obvious reason, why such a pheno-
 menon, so often takes place  among the feathered
 race.   If we  should feed our fowls with more
 calcareous substances, and less of the luxuries of
 the city, we would seldom, or, perhaps never  wit-
 ness such occurrences.   I have no doubt if we
were acquainted  with persons possessing soil, con-
taining  a  large quantity of lime, we  would  find
that all the eggs laid in that neighbourhood, would
have a  stronger covering than elsewhere.  If lime
then, should thus act upon the constitution of the
hen, so as to form the shell of the egg; would it
not be  Philosophic (nay I will go so far as to  say
correct) practice, to prescribe substances contain- 
             Speculations on Lime.          61

ing lime in cases of the fracture of bones.   But in
this instance, as bone differs from the shell  with
respect to the quantity of its ingredients, and per-
haps  I  might have said its quality ; for the one
contains little or no Phosphoric  acid,  while the
other contains a considerable quantity, we  should
advise the use of the phosphate of lime, instead
of the carbonate or  any of the  other  cretaceous
substance without the use  of phosphate  at  the
same time.
  Now  all are convinced that bone must  form in
a smaller space of time in proportion as  the mate-
rials are in the human system which exist in every
bony  substance,  of course then the novel method
I have recommended would produce a union in
the fractured extremities of the bone much soon-
er, than where no preparations of lime had been ad-
ministered.   Indeed I  should  not be astonished
to  hear, that a bone which required six or eight
weeks to become firm  in the old way, would, ac-
cording to the practice just recommended, become
firm in half the time.
  But, here some may say my expectations are too
sanguine,  for in Rickets, there is a decomposition
of the bone, and yet calcareous materials seem to
produce no effect.   Be it so.  Yet there is a  verv
great difference between the simple fracture  of a
bone, and a morbid  predisposition in the whole
bony substance.   I hope then you are all convin-
ced, that because lime does not produce any good
effect in Rickety complaints, that it does not follow
as  a consequence, that  it is so also with the frac-
                       I 
62           Speculations on Lime.
tureofa bone.  Once more,  on mentioning the
foregoing ideas to Dr  Manners, he suggested the
propriety of extending this practice to the fracture
of bones of Parturient women, for here no union
will take place in the usual way, and why ?  Be-
cause all the bony matter is required for the for-
mation of the bones of the foetus, and of course
none  is left to produce a union in her  own frac-
tured bones.
  This I think highly  ingenious, and I would have
done  an injustice to the Author had I  not men-
tioned it.   Lastly, what would be the effect, if all
Parturient  females should  live upon  substances
that have lime, as one of their ingredients, might
not the foetus be formed in a smaller space of time,
and thus abolish the term of nine months. 
      REMARKS ON HEAT,


By Thomas D. Mitchell, M. D.  Fellow of
  the Academy of Natural  Sciences of Philadel*
  phia, Honorary member of the Columbian Che-
  mical Society of Philadelphia, He.

     CHEMISTS, in all ages have been studious
in investigating the phenomena of heat.   Its great
and important agency  in all the processes of art,
necessarily rendered it a subjeet of material inte-
rest.  It was not however, till the days of Dr.
Black, that the subject assumed  a philosophical
attitude.   This  ingenious  man,  from  the rude
theories of the many who preceded him, collected
the outlines of that system which is now so gene-
rally received.
  I am not convinced,  however, that the theory of
heat, as it is  called, has yet attained to perfection.
And perhaps some of the apparent beauties of the
system of Dr. Black, will some day, be viewed as
scientific deformities.  I was led to a more atten-
tive examination of this subject from some remarks
made by my friend Dr. Manners,  in private con-
versation on  the subject of latent heat.   That gen-
tleman stated his disbelief in the doctrine of latent 
64
Remarks on Heat.
 caloric in solids, and wished to have substituted
 the term specific heat.  This much of the cover-
 sation, candor prompted me to state.   After hav-
 ing reflected on the subject with some attention, I
 am induced to believe that there is no just reason
 for the existence of latent heat in solids.   I do not
 beleive that Dr. Bkick originally meant any thing
 more by latent caloric  than  that quantity of the
 matter of heat which rendered bodies fluid.  But
 the extent of his system necessarily involved him in
 some difficulties, and perhaps gave rise to a fre-
 quent misapplication of the term  latent caloric.
 Even that part of the theory relative to the caloric
 of fluidity is involved in some obscurity.  We are
 informed that a quantity of ice at 22° placed in a
 Warm room, will rise to 32°, and then the heat will
 be stationary until the ice is  melted, when it will
 rise in temperature.  Now we are  certain that in
 this case, caloric must have combined with the ice
 although the act of combination did not effect the
 thermometer, and we can only explain it,  by sup-
posing that the affinity between the ice and caloric
 was so great, as to render the absorption of the lat-
 ter insensible, by its rapidity.
   This, however, is a case in which we are com-
 pelled to  give our assent,  because  experiment
 proves the fact, and reason cannot, as I believe,
 overturn it.   If this concession in Science be ne-
 cessary in one  instance, it is not so in all.   And
 I do not think there is any just cause for obscurity
 in the phenomena of caloric so far as regards solids.
 It is in my opinion  very easy in a rational manner 
              Remarks on Heat.            [65

to disprove the doctrine of latent heat in solid
bodies.
  Heat has been called by different specific names,
as absolute, specific,  sensible,  latent,  &c.  And
for each of these, there are perhaps several syno-
nimes. Now I think, it will appear that the term ab-
solute heat, is sufficient to express all that is desi-
rable to be  conveyed by the  term latent heat.
Understand me ; I do not say that absolute heat
is the same with latent heat, by  no means ;  I wish
to make it appear that the term latent heat has been
applied to the heat of solids, when the term absolute
should have  been used.  Thus for example it is
common to say, a piece of iron  contains a quantity
of heat in a latent state, and that by being hammered
this  heat  will be evolved and  rendered sensible.
Now I shall endeavour to make it appear that the
heat was not latent, both according to Dr. Black's
application of the term latent caloric and also from
analogical reasoning.
  In the first place then, I ask  what do we mean
by sensible heat? It is obviously that which is in-
dicated by the thermometer.   The  thermometer
will  indicate the heat of one  body as  180°  of
another as 20°, yet in the  one case, we call the bo-
dy hot, in the other cold.  In the one case, common
phraseology would endow the body with sensible
heat, while in the other, caloric would be latent.
Yet the heat of both bodies is distinctly indicated
by the thermometer, the one as at 20°, the other
180a.  Now although the body at 20° may be call-
ed cold, yet it is relatively hot, that is to say,  it 
 66             Remarks on Heat.
 possesses more caloric in a sensible state, than '4
 body at  15°.  When Dr. Black found that ice
 could be exposed to a great heat without affecting
 the thermometer, he called the heat which com-
 bined with the ice, latent, because it could not be
detected.   But this could not take place with other
 bodies as iron, and this  would  be increased in,
temperature  by the  smallest accession of  heat.
 Yet the ice, as a solid is on a footing with the iron
 in this respect, that it contains, relatively speaking,
 a quantity of sensible heat.   And it would appear
that nearly all bodies while in a state  of solidity
 are influenced alike by the phenomena of heat, but
 that latent caloric or as it is often properly called
 caloric of fluidity, is only concerned in the change
 of bodies from solidity to fluidity.
   Absolute heat is a term used to denote the entire
 quantity of caloric in a body.   Now it is common
 to say, on mixing two substances and thereby pro^
 ducing an extrication of heat, that the caloric is
 passing from a latent to a free  state.   I deny this
 however, otherwise there is no use  in the term ab-
 solute heat.  If the entire quantity of heat in one
 body be 20°,  and  that  of another be 15, the heat
 of the two would of course be 35.  But suppose
 that  the  mixture of these substances is attended
 with a great degree of condensation, it would then
 follow that the heat of the compound could not be
 35, but  something less  in proportion to the con-
 densation.  Now  this  portion  of  heat which  is
 thus given off is nothing more than a  part of the
 absolute heat of both bodits,  escaping in conse 
Remarks on Heat.              67
quence of condensation.  A piece of iron at 20°
contains its proper quantity of absolute heat, the
measurement of which has never been accomplish-
ed.  It is also evident that it contains all the sen-
sible heat indicated by 20°.   Suppose I subject
this iron to the action of a hammer.   The effect
is obvious.   I increase the attraction of aggrega-
tion between the particles of the iron, or I con-
dense it.
   By this condensation, the  absolute heat cannot
possibly occupy as large a space as before since
the particles of the iron are forced into close con-
tact.   It must therefore escape, and in the act of
its evolution, raises the  thermometer and thus be-
comes what we call sensible heat.  Therefore if
the remarks now made be just, Dr Black is in an
error when he says that iron  loses its malleability
by hammering in consquence of the loss of latent
caloric.  It loses its malleability in  consequence
of having been hammered, till it is no longer mal-
leable.  If there be a certain point of union, be-
yond which the particles of matter cannot be forced,
and if by means of any power, we gain that point,
the difficulty is at once removed, and we can easi-
ly perceive that too much hammering destroys the
malleabillity of iron, only by  forcing its particles
into close  contact, and of course that latent heat is
not at all concerned in the process.
   Thus far have I ventured to explain the subject
under consideration, by the  aid  of Dr.  Black's
application of the tlrm latent heat.  I will now in 
68
Remarks on Heat.
a brief manner attempt to establish my position by
analogical reasoning.
  I know the fallacy  of reasoning from analogy.
But nevertheless this mode of argument is some-
times conclusive.
  I have said that by rendering a  solid, as iron,
more dense, we force out its absolute caloric, and
that while we thus make a sensible increase of heat,
we do not affect latent caloric in any way.
  The specific gravity of bodies is always in pro-
portion to their density.  Hence the  truth of the
remark that if it were possible to compress a piece
of cork  into so small a space  that  its particles
would be in as close contact as those of  platina,
we would thus increase its specific gravity in a
remarkable manner.  Now to what should we at-
tribute the  immense  hydrostatic difference thus
produced, but to a change  in  the  aggregation  of
the particles of matter ? we would not  say that
the latent gravity was evolved and rendered  sen-
sible by  condensation.  We would  more justly
conclude that by condensation, the specific gravi-
ty of one body was  increased, and  that by the
same means the heat of another body was render-
ed more obvious.
   It is laid down as a maxim, and perhaps there
is none more true, that when bodies pass  from  a
fluid to a solid state, heat is evolved.  This plain
proposition, is however, misunderstood by many.
It is frequently asserted,  that *he heat which is
sometimes evolved on the passige of bodies from
fluidity to solidity is merely latent heat rendered 
Remarks on Heat.
69
sensible.  This I do not beleive.  For if such bo-
dies be condensed, the very act of condensation is
sufficient  to  produce a decrease of the absolute
heat, which in  its escape, becomes sensible.  It
may be said  that this rule is not applicable to all
cases, since water is enlarged by freezing and not
condensed.   This  however, is a rae exception,
and it is a matter of doubt, whether water does not
actually condense by freezing, even  though  its
bulk be enlarged.   For  it is a  fact  generally ad-
mitted, that  ice contains a  large quantity of air,
which not only explains its  levity, but is likewise
in my opinion, sufficient to satisfy any man of the
error of those  who suppose it to be enlarged in
passing from a fluid state.
  I  do not deny that the latent heat of water may
pass off when this fluid  assumes the solid form ;
but I contend,  that in all cases of this change, the
heat which is  perceptible,  is  the absolute  heat,
evolved by condensation, and not as some suppose,
the latent heat, rendered sensible.
K 
ON  THE OXYACETITE OF IRON
M a test or  reagent for the discovery of Arsenic.
   By James Cuteush.   Professor of Chemis-
   try, He. in St. John's College.


   THE importance of obtaining correct deduc-
tions, in experimental inquiries, is acknowledged
to be of considerable utility in the  practical re-
searches of the chemist.  Especially in the analy-
ses of bodies, whether solid or fluid, our attention
is directed to the employment of a number of rea-
gents, which are to determine, beyond the possi-
bility of doubt, the presence, or absence, of cer-
tain bodies.
   Reagents are, as Mr. Accum so justly observes,
the  "compass  by  which  the  Chemist steers."
When chemistry shall have arrived to the summit
of perfection, it will be then, and not till then, that
we shall draw conclusions, which the power of ge-
nius can not overthrow; and as we progress in this
knowledge, the more we would be able to deter- 
         On the Oxy acetite of Iron, He.       71

 mine the correctness of any deduction founded
 on the immutable laws of nature.  As to the rea-
 gents employed for  the detection of arsenic it is
 well known that a number have been recommended.
 I have been led to make some  experiments with
 the oxyacetite of iron, as a  test  for arsenic, from
 the circumstance that iron and arsenic, in peculiar
 states of combination, form an insoluble compound
 of a brilliant orange tint.
   We shall first, however, offer some remarks on
 the preparation, and then describe its application.
   When iron filings is degested in acetous acid
 (distilled vinegar) a portion is dissolved untill the
 acid is  destroyed, a compound being formed of
acetous acid and iron.  During  this operation, the
iron is oxydized, to the minimum only, at the
expense of the water in the acetous acid, which is
then taken up by the acid,  forming the acetite of
iron : at the same time a portion of hydrogen gas
is evolved in consequence of the decomposition of
the water.  Or, if acetite of lead (sugar of lead)
and  sulphate  of  iron  (coperas of the shops) be
mixed together in solution, a double decomposi-
tion will ensue, sulphate of  lead will be precipita-
ted, and acetite of iron be held in solution.   This
solution of iron is well known in the arts, by the
name of iron liquor. It is also prepared by dissolving
iron in the pyroligneous acid, which  is obtained
by the distillation of wood.
   But when the peroxtd of iron or iron oxydized
 to the  maximum, is combined with the acetous
 acid, another compound is formed, called oxyace- 
 72       On the Oxyacetite of Iron, He.
 lite of iron, which I propose as a test for arsenic.
 This preparation I made in the following manner:
   Equal parts of the red or oxysulphate of iron
 and acetite of lead, were mixed together in a suf-
 ficient quantity of water,  and the sulphate of lead,
 which was precipitated, was separated by the filter.
 The oxyacetite of iron,  which passed  the  filter,
 was of a beautiful reddish-brown colour.
   This solution, added to another of arsenic, gave
 a precipitate of a beautiful orange test,  which, on
 examination, proved to be a compound  of arsenic
 and iron ; for on exposing it to heat, the arsenic
 was volatalized, whilst the ox id of iron remained
 behind.
   From an experiment made to ascertain the 'jer
 cent, of each metal, in the precipitate, I found
 that my experiment indicated the following pro-
 perties ;
          Arsenic   .55 Or  arsenic 40
             Iron   .45      iron    35
                 ——      oxygen 25
                 1  00           ----
                 ----           1  00

   It may not be improper to state,  that the oxy-
 sulphate  of iron was prepared by digesting in a
 dish, eight  parts of the green sulphate  and  two
 parts of nitric acid ;  a sufficient heat being applied
 to decompose the acid.   In this case,  a part of
 the oxygen of the nitric acid united  with the iron
 of the sulphate, forming the  per  oxyd, whilst the
 other part was disengaged in  union with  the azote
in the form of nitric oxyd  gas or  nitrous gas. 
On the Oxyactite of Iron, He.       73
The per oxid in  union  with the sulphuric acid,
formed the oxysulphate of iron.
  If arsenic in the state of acid, whether the arse-
neious, or arsenic, be combined with potash in the
form of arsenite, or arseniate of potash, and added
to the oxyacetate of iron, a double decomposition
would ensue.
  The difference in the colour of the precipitates
in the combinations of the arsenic and the iron,
depends on the degree of oxydizement in the so-
lution of iron.  Hence it is, that with the common
acetite of iron, in which the protoxyde of this me-
tal is dissolved, the colour of the precipitate pro-
duced with the  arsenious acid, or  the common
white arsenic of commence, is of a greenish-yellow,
the precipitate from the oxyacetite being  of a
bright orange.  If either of the acetites contain the
least portion of the sulphate of iron, it prevents the
precipitation of the arsenite.
  Hence also, if arsenic acid (in  which the dose
of oxygen is at  the  maximum) be present in a
fluid, thecolour produced with the oxyacetite of
iron will be of a blueish-white.
  Therefore, in common will all the other salts of
iron, the arseniate of iron will combine with an ad-
ditional dose of oxygen, constituting the  oxy-ar-
seniate.  Richard Chenenix  Esq.  found,  that the
oxy-arseniate of iron contains
                  Acid    42.4
                  Oxyde  37.2
                  Water  29.4
1 00 
74        On the Oxyacetite of Iron, He.
  On the same principle as  the oxyacetite of iron
is used as a test of the discovery of arsenic, Scheelc
I think recommended some  of the solution of cop-
per.  If acetite  of copper {distilled verdigrice of
the shops) be added to an arsenical solution, the
arsenic will be precipitates in union with the cop-
per, forming the Scheele's green.  This  precipita-
tion of arsenic by solutions of copper, has rendered
the latter a  test  for arsenic.   Other reagents for
discovering this metal have been recommended. 
                THOUGHTS            /

                   ON THE

    PRINCIPLE OF EXCITABILITY.

By George Ferdinand Lehman.  Vice Pre-
  sident of the Columbian Chemical Society, Ho-
  norary member of the Medical Society of Phila-
  delphia.

  THE important discoveries, of late years  in the
science of medicine, and chemistry, have changed
the complexion of nearly all that was before known.
In ancient days, when  science was just evolving
from darkness, nothing like perfection could be
expected, from the sons of philosophy.   Many of
them however, entered the labyrinth of nature,,
and gave to the world her secrets.   They had no
marks to guide them, and were carried along by
impulse, through regions of truth, and fiction.
These uncertain wanderings brought within their
grasp facts, though  in  a confused state, which
served to enlighten the path of modern philoso-
phers.   The  sweets of the  ancients, have been
culled  and improved.   Among the various phe-
nomena which appeared to them, life was the prin- 
  76        Thoughts on the Principle

  cipal. The materiality of it was contended for by the
  prophets.   Oxygen gas with which  we are  now
  so well acquainted, was the pneuma, which Aris-
 totle thought existed in the air, and combined with
 the blood.  Chrysippus  and Bacon  were mate-
 rialists.*
   The importance of excitability must be obvious
 to the most superficial observer.  It is the medi-
 um through which stimuli act, to excite the mind,
 and body.  Where would have been the  sublime
 works of a Milton, Pope, Cowper, and Goldsmith,
 had they been  devoid  of this  capacity ? Where
 the  useful discoveries of  I avoisier,  Priestley,
 Franklin and Rittenhouse? They would all be
 covered  in mystery  and darkness.   The lasting
 monuments of science, erected by the industry and
 perseverance of the children  of genius, would be
 wanting.   The face of nature would consist of no-
 thing more than a mass, of inanimate matter,  de-
 prived of it.   Wherever  life,  or motion  exists,
 there must be a capacity of being acted on by sti-
 muli.  The most enlightened philosophers of the
 present age admit that life is a forced  state.  Some
 writers on animation,  affirm that we cannot admit
 of a vivifying principle ; if this theory be correct.
 That indeed would be the case were we born with
perfect life, when in fact it is only a  capacity of
life.   It is certainly at variance, with Haller's Vis
 Vitae, and Cullen's Vis Medicatrix Naturae. The
best mode of  studying, and  understanding the
laws of Nature, is by  driving her out of her uni-
* Johnson's Animal Chemistry 
Of Excitability.              77
form track by experiment.   This as it applies to
the human body, in the present inquiry, is im-
practicable.   We  must reason principally  from
facts, experiments performed on the brute creation,
and  analogy.   I have always been of opinion, that
oxygen acted more than a  negative part, in  the
system ; but it would be too tedious at this time,
to mention the facts on which this  belief is found-
ed.*  That oxygen is the substance from  which
excitability is generated, appears probable from the
following circumstances.t
   1. Respiration as a universal function through
out animated nature, first attracts our regard.  We
are convinced, from the effect  of placing animals
in vacuo, or of tying the trachea, that it and life
are intimately connected.   In  what consists  the
necessity, of this connexion ?  Does the air conti-
nue existence, by stimulating the system? or does
it only serve for the production of animal heat ?
In answer to the preceeding question,  it is suffi-
cient to observe, that  incetants of the most pow-
erful kind applied to every part of the body, in a
torpid state, as Adam was before he received into
his  nostrils, the breath of life, Avill not produce  vi-
tality.  If it were only  requisite to the production
of heat, animals deprived of respiration, and exposed

   * Although some of the greatest English chemists, (among whom
way be ranked Murray, and Thompson) stand in defence of the ne-
gative theory : their reasonings, and deductions, are not sufficiently
weighty, to prostrate that promulgated by the Chemists of France.

      | <\;-^:mcristhe firmest supporter of this opinion.
                        1* 
78          Thoughts on the Principle
to a temperature equal to the blood should live
considerably longer than those in a cold situation.
Experiments  convince us  that this is not the
case.   They die nearly at the same time; but
we sometimes observe heat fluctuating in the body
hours,  and even days  after death,  which  shews
that the system is not indebted altogether  for its
caloric to this function, and that it is not connec-
ted with life, in this way.
  Is the oxygen of the atmosphere,  absorbed by
the blood, and conveyed to every part of the body
impregnating it with vitality ?  Venious blood, or
that on which the air has not acted, will, in a very
short  time destroy life.  Nitrogen,  and oxygen
with a small portion of carbonic acid gas, are the
substances  composing  the  atmosphere:  conse-
quently it must be owing, to one  or all of these
gases impregnating the  blood.   Neither carbonic
acid gas, nor  nitrogen will support animation,
nor will the combination of any other gas with ni-
trogen (except oxygen.)  As but a  small portion
of azotic gas, is absorbed, and  if the experiments
of Pepys, and Allen be correct,  none at all* it can-
not therefore be considered the active ingredient.
Is it oxygen ? no other explanation, can reasona-
bly be offered.
  2t. If we place animals in oxygen gas, they live,
and seem to do tolerably well;  but after a certain
time their vital energy in every respect is increas-
ed :  this is explained exactly in the same manner,
Pepys and Allen on Respiration. 
                Of Excitability.             79

 as blowing a fire with a pair of bellows; here fuel
 is added to flame.
  Dr. Hare mentions in one of the volumes of the
 Philosophical Transactions of London ; that mice,
 birds, &c. live as long again, in a vessel where he
 had crowded  in double the quantity of air by a
 condensing engine, than they did when  confined
 in air of the common density.   This clearly evin-
 ces to us,  that something must have been derived
from the atmosphere necessary to sustain life.—
 Was knot oxygen?             *m
  The inspiration of nitrous oxyde gas, affords an
 argument in defence of this opinion, it excites  not
 only the mind and muscles : but imparts vigour,
and force to every part of the human frame.  The
celebrated Davy, after he had inspiredit exclaim-
ed,  " nothing exists but thoughts, the universe is
composed  of impressions, ideas, pleasures  and
pains."  Others rave about like madmen.   Is this
 increase of vitality,  owing  in part to the absorb-
tion of oxygen ? This is rendered probable from
the  succeeding facts.
  Davy inspired 102 cubic  inches  of  this gas,
 mixed with one fiftieth ©f common  air.  Forty
 inches disappeared, and the remainder sixty-two
 inches by analysis consisted of
            Carbonic Acid    3.2
            Nitrous Oxyde   29.0
            Oxygen           4.1
            Nitrogen        25.7
  Thus you perceive, that nearly all the oxygen
 was absorbed.   This however,  is not altogether 
80         Thoughts on the Principle
satisfactory ;  if it were the inspiration of oxygen
gas alone, should have these effects.   Owing to
the proportional combination, of the gasses form-
ing nitrous oxyde, it has a peculiar power; it ele-
vates the nerves,  to their highest capacity ; but it
is that kind of elevation, which is not succeeded
by  debility.   The  blood of animals  killed  by
breathing this gas, is a purple red, spots of a simi-
lar  colour are to be seen  in the lungs ;  and the
muscles to all appearance possess great irritability.*
  It is the known effect, of the  oxygenous princi-
ple of the atmosphere, when duly inhaled from a
current breeze, not only to saturate the blood widi
floridity ; but to  exhilerate the spirits in a high de-
gree, invigorate, and redden the muscular fibre: be-
stow energy on every nerVc, and call forth at once
mental, and corporeal strength."
  Hence the necessity of a pure air is obvious.
Why do we  so often observe  people  fainting, in
in crowded rooms ? and why does the introduc-
tion of fresh  air,  immediately restore them ? Can
these questions be answered, in any manner con-
sistent with reason, unless we resort to the agency
of oxygen.   Is  not the syncope the  effect of the
deficiency of vital gas? The gaping and yawning
which takes  place in large assemblies,  I have no
doubt is owing to the same cause. The uneasiness
in the heart and faintness, which has been experi-
enced by those ascending high mountains, is to  be
explained in a similar way.

        * Davy. Trotter on Nervous Temperaruent. 
                &f Excitabiftty.              d\

   .?. The wavering state of excitability, is in sup-
 port of it.  This is obvious sometimes  in health,
 but most frequently in  the diseased state of  the
 system.  In an inflammatory fever, the pulse is
 generally full,  and quick :  the eyes and face  suf-
 fused with blood, the respiration is frequent, and
 often laborious; the whole body is excited.   Is
 there  any necessity, for  this quick inspiration ?
 Certainly, the different stimuli acting on the body
 in the  disease are so great, that the excitability
 would soon be expended, and death would be  the
 consequence if there were not a preternatural sup-
 ply of vital air.  Wlience docs the system obtain
 this addition of stimulability ? is it not from  the
 greater quantity of  oxygen conveyed  into   the
 lungs ? on the  contrary in  Typhus fever, where
 the pulse is  weak,  and feeble, countenance pale,
 and respiration performed  slow, and languid  the
 patient is weak, and almost lifeless.
   Asthmatic patients long very much for pure air;
 because the air vesicles of their lungs are filled witli
 serum, and the air cannot come sufficiently in con-
 tact with the blood.  These people are  generally
 cold, and in  a  weak state, the pulse being very
 slow.*   Does not this depend on a less quantity
 of oxygen in the blood ? I have merely specified
 these cases, to  render the position more obvious;
 it applies generally to all diseases of high, or low"
morbid action.
*  Breefi1" Aathroa-; 
 ®2         Thoughts on the Principle
   6.  "Birds whose pulmonary organs, arc conti-
 nued into the  abdomen by several  membranous
 sacs,  and  whose hollow bones communicate with
 the lungs  ; consume a  great quantity of oxygen,
 either on account of the extent of their pneumatic
 receptacle, or because their respiration is frequent,
 and often  sudden; thus the habitual  temperature
 of their bodies is ten degrees above men, and the
 Mammifery or those having teats."   They arc
 extremely active, and energetic and seem to pos-
 sess a superabundance of life.  Those birds which
 possess most muscular power, and  run about as
 soon as they escape from the shell,  are generally
 supplied with a larger receptacle for air in the shell
 than these dependent for their subsistence after being
 hatched;  now as this air is allowed to be oxygen
 does it not generate excitability to be acted on by
 stimuli.   " In reptiles,  on the contrary, the vesi-
 cular  lungs of which, receive only a small quan-
 tity of blood, and offers but a small  surface respi-
 ration takes place at more distant intervals, conse-
quently they  have a temperature  never  above
seven, or eight degrees.*   And it is  scarcely ne-
 cessary  to mention, that their motions are for the
most part  slow, and languid.  Does not this point
 out an intimate connexion between  life and oxy-
 gen?
   7.  By injecting this gas  into the  blood-vessels
 in a quantity  sufficiently large to produce  death,
 the heart,  and muscles possess irritability in a de-
• Richerand's Physiology 
Of Excitability.             83
gree considerably greater than where life is extin-
guished from any other cause.  Does not this ren-
der it probable, that the vital principle is oxyen ?
If the other gasses are employed, death willbefthe
consequence, and  the irritability of the  muscles
has decreased, or nearly wasted.   Is not this ano-
ther stone added to the foundation ? Why should
the muscles have such a susceptibility to the action
of stimuli, after the application  of oxygen only ?
  8. Black blood,  or that destitute of oxygen is
fatal to animal life; this is clearly proved  by an
experiment of Bichat.  " I opened," says this in-
dustrious author, the "carotid, and jugular of an ani-
mal ; and received in  a syringe heated to the tem-
perature of the body,  the fluid poured out by the
latter, which I injected into  the  brain of the for-
mer which had been tied on the side next the heart
to avoid hemorrhage, the animal was almost imme-
diately agitated, he appeared to be undergoing si-
milar sufferings to those produced by asphixia, of
which he  very soon  shewed all the  symptoms:
animal life was entirely suspended, the  heart still
continued to beat, and the circulation to go on for
half an hour at the end of which time death termi-
nated organic life also." " The black blood," conti-
nues he, is no  doubt fatal to the brain by striking
it with atony, by its contact,"  or in other words,
abstracting its  vital power, rendering it  incapable
of motion.
   We can inject the arterial blood of  one animal,
into the carotids of another, and it will not cause
death ; this shews that the consequence of inject- 
 84         Thoughts on the Principle

 ing black blood, into arteries docs not depend  on
 any change  which  could take place in this fluid
 passing from one body to another; if this .were the
 Case death should occur in both instances.
   9. By impeding the progress of arterial blood
 to a limb, or any part of the body, the excitability
 is destroyed, and partial death occurs.   It is also
 evident in aneurisms.   When an artery is taken
 up, the death of the extremity sometimes succeeds
 and in a very rapid manner.   This cannot be the
 consequence of the loss of motion by the deficien-
 cy of blood, or any other fluid equally stimulating
 should preserve life, nor can it  be owing to the
 want of nutritious substance, because this is an ex-
 tremely gradual process, and its absence could not
 be so suddenly perceived.*  It is the want of ex-
 citability ;  and I  have no doubt but one third of
 the blood, which is naturally destined for the sup-
port of a limb, or in fact the whole body, would be
 sufficient if highly oxygenized.
  In youth, the arteries are larger than in advanced
life, and  the blood which  is peculiar to them is
 great in quantity, hence young people are general-
ly vigorous, and active ; but in old age the arterial
 system dwindles, while there is an enlargement of
 the venous, need I add that debility, languor, and
paleness accompany it.
  10. The  oxydes of iron, and steel are particu-
larly useful  in diseases of great  weakness.  May
not this be owing to their capacity, of combining

          * Lichat's I'.n geological Ksscarches? 
            Thoughts on the Principle         85
 with a much larger <.umtity of oxygen, than most
 of the other metals ;  consequently affording a
 greater proportion to the system.   The  effects of
 these medicines, are, to increase the pulse, and pro-
 duce a lively florid appearance in the face.   Pro-
 fessor Coxe observes, that it  is highly  probable,
 iron would have no action on the body when taken
 into the stomach unless  oxydized.*
   11. The pulses of the generality pf people arc
 slower in winter than they are in the warm season.
 This perhaps may be accounted for, without re-
 sorting  to  the  sedative action  of cold.    It h
 known that the chief source  of vital air, is  from
 the  vegetable  kingdom.  In  the cold  season of
 course  this great spring  is almost entirely cut off*.
 The atmosphere probably contains a less quanti-
 ty of oxygen gas.   I am not sure whether any ju-
 dicious experiments have been made, to ascertain
 this point with accuracy : however a very  small de-
 ficiency of oxygen, might have the effect, and if
 no great change could be perceived by our uncer-
 tain experiments, the assertion would not be un-
 reasonable.   It is not  as inconsistent, as to  sup-
 pose that no impurities exist in the air, during the
 prevalence  of a malignant, or epidemic distemper
 because  they cannot be  discovered by the eudio-
 meter.
  12. The  inhabitants of the cold countries, of
 Lapland, an I Iceland are by no means as lively, as
those of warm climates. Biumcnbach asserts,  that

              * Goxe's Dispensatory.
                      M 
 t>6           Of Excitability.
the heart of a Greenlander, in consequence of the
coldness of the  climate, pulsates only 30 or 40
strokes in a minute.*
  Does not this depend on a less quantity of oxy*
gen in the air ?  These  observations  it must be
confessed are only conjectural; but we should at-
tend even to conjectures,  when countenanced by
appearances, and analogy.  Like the Ignis Fatuus,
which frequently leads  us into bogs,  and quag-
mires,  yet  occasionally,   conducts  us  through
the mists of night with safety;  they will serve,
if  true, for the  elucidation of  many  pheno-
mena, in the healthy, and  morbid  states of the
body.
   13. It is  observed by Dr. Rush, that we make
longer,  and fuller inspirations in the sleeping, than
waking state.   This, by admitting into the lungs,
a greater proportion of vital gas favours the accu-
mulation of excitability ; hence one ofthe reasons
why diseases so frequently attack us at night,
   14. In animals in utero, there is  but a small
 quantity of excitability ;  but it is sufficient as in
this situation, there are no powerful stimuli or ex-
 ertions  to expend it.  That they possess less vi-
 tal power, is evinced by suffering brutes  to bring
forth their young in water, and in common  air,
 by placing the last directly in water, if it  has ever
 breathed, you will perceive its struggles and emo-
 tions are much greater than the former.   How can
 this fact be explained unless we admit oxygen, to

    * Blumenhach's Physiology, Caldwells's TYan-ihuion. p. 79. 
Thoughts on the Principle          87
be the source of stimulability ?  In  the  latter  the
quantity is  increased, it  therefore requires more
violent actions to waste  it.  To shew with more
precision the correctness of this assertion respect-
ing the expenditure of excitability, I obtained two
cats, and having immersed one in water, for the
space of one or two minutes, I poured over it some
hot water; the effect was very inconsiderable, it
scarcely moved.  By merely dropping it on  the
other, great agitation was  the consequence.  The
irritability of the cat half drowned, was unques-
tionably diminished, and this diminution was the
effect of the stoppage of respiration, preventing the
absorbtion of oxygen ; while at  the  same  time,
there was a waste of vital power, by the actions of
the cat in the water.
   15.  The  weariness, and debility produced by
excessive exercise,  or labour can be  explained
only on a supposition, of the wate of this principle.
The circulation, from the pressure of muscles, agi-
tation of the body, and other circumstances, is in-
creased, to a very considerable degree.  Upon
this account a greater proportion of blood is  sent
to the lungs than usual.  It is again hurried out of
the thorax, only in part oxygenated, and so  carri-
ed throughout the system.  If this action conti-
nues a sense of suffocation occurs, and the subject
soon falls, by the expenditure  of excitability, or
by the inability of the lungs, to supply the blood
with vital gas to keep up  animation.  To render
these observations almost indisputable; it is only
necessary to take two animals coeteris paribus, and 
 H8           Of Excttability.
 by irritating one of them, keep it in continual mo-
 tion for some minutes ; and let the other remain in
 a  state of  quiescence.  Then place them in  air
 tight vessels, and the latter will be  seen  to live
 longest.  Many of the effects of the stimulating
 passions,  might be solved in the same manner.
   16. Those people who possess broad chests, arc
 for the most part strong and healthy. They gene-
 rally are of a rosy appearance, and frequently pos-
 sess great vivacity.  On the other hand, view the
 small, and slender made.  They are pale,  and not
 very excitable.
   Is it not probable, that this may be the conse-
 quence of their inacpacity of inhaling much air ?
 and doos the liveliness florid countenance, &c. ac-
 companying the broad chested man,  depend on the
 large inspiration of air ? In animals in  which the
 pulmonary  system is most complete, and spacious,
 life is greatest, or in other words, the capacity of
 life is in the highest degree.
   17.  The phenomena of plants, though it may
 not be a fact directly in point, perhaps will reflect
 some  light on the  subject.   We know they are
 possessed of irritability, and other powers belong-
 ing  to animals.  Now if oxygen, is the principle
 of animation in one, it must  be so in  the other.
 This idea is  not  invalidated, from the circum-
 stance of vegetables flourishing and doing  well in
fixed  air.   The  life  of  plants  is on  a much
 lower scale than  animals,  hence  the depriva-
 tion of oxygen to  them by  the air, is  not at-
 tended witii immediate bad effects.   Reptiles arc 
             Thoughts on the Principle        &9
nearly on a par with them in this respect.   Plants
have the power  of abstracting vital gas from the
water, carbonic acid, and others of their nutritious
substances;  which maintains  their  irritability.
Vegetables placed in oxygen gas as pure as it can
be obtained will not long survive in this situation.
Horticulturists are so  well acquainted with  this
fact, that they not unseldom place a glass  vessel
over young plants to prevent its contact.   A mo-
derate quantity  of vital air,  is  favorable  to the
growth of plants.
   18.  Water in all probability  is decomposed as
it comes in contact with the animal fibre ;  and this
is another way by which  nature, affords the prin-
ciple of life  to animals.  The  rotifer which is a cu-
rious insect, after being dried, by moistening it
with  water,  returns to life.   This certainly must
be owing to the oxygen of the water affording ex-
citability, consequently life.
   Fishes decompose water, with great facility even
without the influence  of their gills,  as has been
shewn by the experiments of  Provencal and Hum-
boldt.  The carbonic  acid  they reject,  does  uot
equal more  than * of the oxygen absorbed : hence
their extreme vigour, and activity.*
   19. It is well known that the  white  organs, and
other parts of the body in a healthy state, have but
a small degree of sensibility ; but  when inflamma-
tion occurs, and blood is propelled to them with
Telocity,  their  vitality is amazingly increased.
• Mcmolrai de laSoci^te D'ArcrUil. 
 90              Of Excitability.
 Does not this arise from more oxygen being sent
 to the part i Let us inquire, how far this  idea is
 corroborated by reason. In the natural state of the
 white organs, a light fluid circulates through them,
 and  they  are nearly destitute of excitability; in.
 flamed their functions are materially altered. What
 before could not be affected by the most powerful
 stimuli, are now acutely, sensible to the slightest
 impressions.  Red  blood traverses  the  canals,
 which were before occupied alone  by serum.
 The vital power is in proportion to the red blood
 present.
   20.  Hybernating animals,  possess vitality  in a
 very low degree during the winter season,  as fre-
 quent, experiments demonstrate.   If powerful
 irritants are applied to them, they  either have no
 effect at all; or  owing to the disproportion of sti-
 mulus, and excitability, the death of the animal is
 the consequence;  but if left alone and undisturb-
ed, when  spring approaches, beariiig on his wings
 the gentle gales of Heaven, and the  vegetables be-
 gin again to impregnate the atmosphere  with vital
 gas ? These animals feel the change, inspire new
life, and are excited into motion, and activity.
   It has been asked if oxygen is a stimulus.   It
 will kill if used in excess,  but this abstracts no-
thing from the solidity of the idea, of its  being the
vital principle;  because  it is not  supposed that
oxygen gas, simply produces the vital power, but
that a combination takes place in the animal fibre.
The most natural stimuli  under similar circum-
stances, will have an analogous effect.   Thus thr 
               Of Excitability.              91
mind of  man, becomes shattered, and  deranged
by the preternatural predisposition of blood to the
brain, a certain degree of  which,  is necessary to
existence.  Thus the burning wick, is extinguish-
ed by the application of too much oil, and the ship
upset by  the raging winds.   Every  philosopher
knows, a  definite  quantity of oxygen gas will in-
crease the stimulability of the body.
   I shall now offer a few thoughts, on the origin of
excitability.
   It was long believed, before  and even after we
were taught to look externally, for the cause of life,
that the brain was the grand reservoir from which
the body derived its existence.   This opinion has
been sanctioned by men, who shine conspicuous
in the temple of Science.   Darwin observes, " As
the sensorial power, or spirit of animation, is per-
petually exhausted, by the expenditure of it in fi-
brous contractions ;  and is perpetually renewed,
by the secretion, or production of it in the  brain,
and spinal  marrow.    The quantity  of animal
strength must be in a perpetual state of fluctuation
on this account."
   If it were necessary, we might bring forward evi-
 dence of a later date.    Motion can be excited  in
 the heart, and other muscles, by the application  of
 stimuli, a considerable time  after  death.  Bichat,
 who was permitted to experiment on the bodies,
 of those unfortunate  beings who fell beneath the
 guillotine in the year 1798 in France, produced mo-
 tion in the muscles, by irritants long after the head
 had been separated from  the  trunk.   There are 
 92          Thonghts on the Principle
 animals  destitute,  of brain  altogether; and  who
 has ever discovered the sensorium of plants, yet no
 one will deny that they possess irritability.  Tur-
 tles, and frogs, after  their heads have been cut off}
live hours, days, and even months.   The different
pieces of polypi will  live after being cut asunder ;
and the heart in the  growth of the foetus, is first
formed.
   These facts prove that the brain, cannot be the
fountain of  excitability.   Whence  then  does it
originate ? Every part  of the animal frame, is en-
dowed with excitability, though in some it is scarce-
ly perceptible.  Those parts which have  most of
it, are supplied with the greatest quantity of arteri-
al blood, and it  is  distributed through every  mi-
nutiae of the  body,  by the small capillary vessels.*
Does the oxygen gas unite  with the animal fibre,
in the same state that it entered into the circulation
or does it undergo  a decomposition ? Can it com-
bine with the nitrogen of the fibre,  in such a  pro-
portion, as to produce something allied to nitrous
oxyde gas. This seems probable from the pheno-
mena attending the inspiration of this gas.  Here
let us cease the  strain  of  conjecture, " shadows,
clouds, and darkness  rest upon it."

   " Dr. Samuel  Jackson, to whose ingenious dissertation I am in
debtee! for several facts in this essay. 
                 ANALYSIS         Y

                    OF A


        MINERAL SPRING,

At the Willow Grove, Montgomery, County, Penn-
  sylvania.  By  John  Manners M. D.  and
  Thomas D. Mitchell M. D.

  THIS spring is distant from Philadelphia about
14 miles, and in a country, where the soil is ex-
tremely stony.  Nothing, however, very remark-
able, presents itself to view in the vicinity of the
Spring.
  In order to analyse  the water satisfactorily, it
was examined at its sources.  It exhibits no very
remarkable appearances, except that in color  it is
rather of a blueish cast. It is covered frequently in
the course of a day, with a thick scum,  indicative
of the existence of sulphuretted Hydrogen.
  In the analysis,  the following tests  were em-
ployed and their effects noted as follows, viz.
  1. Litmus Paper....No change.
  2. Turmeric do.      do.
  3. Tinct Galls....A dark  purplish red color.
                       N 
94        Analysis of a Mineral Spring.
  4. Prussiate of Potash.... A lightblue which be-
came much  darker by  the  addition of sulphuric
acid.
  5. Sulphuric acid....No change.
  6. Muriatic acid.      do.
  7. Nitrate of Silver....A white precipitate with
a greenish cast.
  8. Sulph. of silver....A white precipitate which
became purple in a short time.
  8. Acet Plumbi....A slight turbidness.
  10.  Mur. Barytes....No change.
  11.  Nit. Mercury        do.
  12.  Acet. silver....A slight turbidness.
  13.  Tinct Soap    do.     do.
   14.  Ammonia....No change.
  15.  Mur, Hyd....No change.
  16.  Oxalic acid      do.
 • On  shaking the water it emitted an  Hepatic
smell.
  Some of the water was brought to the city, and
three ounces of it were boiled down to 2 ounces;
then it was tested for alkali, but none could be de-
tected.   Pruss. potash added, gave a blue  precipi-
tate much increased by sulphuric acid.  This was
suffered to  stand 24 hours, at the expiration  of
which a copious precipitate had fallen down, which
proved  to  be prussian blue,  weighing 6  grs.
From the above analysis, the following inferences
are necessarily drawn.
  1. The non-existence of carbonic, or any other
acid in an uncombined state.
  2. The presence of iron is fairly established. 
         Analysis of a Mineral Spring.        95
   3. The water contains sulphuretted Hydrogen,
 which  is  evinced  both  from  the  effects  of
 agitation, and the results of the tests employed.
   4. No copper exists in this water, as is proved
 by the ase of ammonia.
   5. It is not found to contain the smallest quan-
L ty of lime. 
AN ENQUIRY
 IVhether Mr. Berthollet was warranted, from
   certain experiments, in framing the Law of Che-
   mical affinity, "that it is directly proportional to
   the quantity of matter*'' By Franklin Bache,
   Vice President of  the   Columbian  Chemical
   Society.
       *
   We shall place the subject under three heads: in
 the first place, we shall attempt to prove that his ex-
 periments did not warrant him  in the conclusion
 which he has drawn 2d. We shall consider what is
 the proper conclusion,  and 3d.  how it  happened
 that Mr. Berthollet was so egregiously mistaken in
 the tendency of his own experiments.
  Weshall premise our observations with an extract
 from Thomson's Chemistry;  this distinguished
 chemist speaking on this subject, has the following
 words.   " And it has lately been demonstrated by
 Berthollet to hold in every case : thus a given por-
 tion of water is retained more obstinately by a large
quantity of sulphuric acid than by a small quantity.
Oxygen is more easily abstracted from those ox- 
               An Enquiry, He.             97
ides, which are oxidized to a maximum, than from
those which are oxidized to a minimum ; that is to
say, that a large mass of metal retains a given quan-
tity of oxygen, more violently than a small mass."
   The above are instances, which Mr.  Thomson
gives as proofs of the law, as Berthollet stated it.
Let us examine whether they are really proofs.
Let us trace him through his reasoning.   He says
" a given  portion of water is retained more obsti-
nately by a large quantity of sulphuric acid  than
by a small quantity ;" therefore, he concludes that
chemical  affinity is directly  proportional to  the
quantity of matter—but to prove the fallacy of this
conclusion, let us view his proposition in another
light equally true ; it is this; a given quantity of
sulphuric  acid is retained more obstinately by a
small quantity of water, than by a large quantity;
therefore,  we conclude that chemical affinity is in-
versely proportional to the quantity of matter; but
this is a conclusion diametrically opposite to that
which Mr. Berthollet draws ; how is this to be ex-
plained, both conclusions  cannot be  true ? we an.
swer, by proving that Mr. Berthollet's proposition is
not universally true, but under certain circumstan-
ces only,  which circumstances are  that the two
different portions of the body, compared with any
other, must be both greater than that quantity which
would constitute a minimum of attraction, between
the body of which we take the two portions and the
third,  with which it is compared, or if not both
Greater, but one  less and that not as  much below
the minimum  astheotheris above: we will explain
ourselves by an example, before which we must fix 
 98            An Enquiry,  He.
 for our convenience an arbitrary point, at which
 this minimum of attraction takes place;  we  say
 arbitrary, because,  nothing but  experiment  can
 decide it, and that  we are not prepared to make;
 we will state this  point  for our convenience, at
 equal quantities, thinking it more probable  that
 experiment would establish it there ;  now for ex-
 ample, let us once more take Mr. Thomson's own
 words, "a given portion of water is retained more
 obstinately by a large quantity  of sulphuric acid,
 than by a  small quantity."  The question is, is
 this true ?  we will  prove it so only  in particular
 cases; and the particular case  in which it is  not
 true, is the following ; let us take two pounds of
 water, in separate vessels, and two portions of sul-
 phuric acid, namely, 20 grains and 4 drams :  to
 one vessel  we will add the 20 grains  of sulphuric
 acid,  to the other, the 4 drams.  Now the attrac-
 tion between the water and the 20 grains is great-
 er, than between an equal quantity of water and 4
 drams ; that is to say, a given portion of water is
retained more obstinately  by a small quantity of
 sulphuric acid, than by a large quantity,   i ius is
the conclusion from this particular instance, which,
as we premised, is diametrically  opposite to that
drawn by Berthollet.  It may be asked, what right
we have to conclude as we have done ? we answer,
to avoid the error into which Berthollet has fallen,
that of considering water inert; for the sulphuric
acid is as much retained by the water, as  the wa-
by the bulphurie acid; their action is reciprocal,
their union cnemical. 
               An Enquiry, He.             99
  We have mentioned the example in which the pro-
position is not true, and we state it in words, not to
be true, in all those  cases in which the compared
portions are  both under the minimum of attraction,
or if not under, but one above, and less above than
the other is below.  Let us illustrate by example ;
thus, having premised that the attraction between
equal quantities of  bodies  combining in  indefi-
nite proportions is at a minimum :
  Therefore the affinity between a pound
     of water and a pound  of sulphuric
     acid, may be expressed by           .0
Then dividing the grades betweeen the minimum
and maximum  into  8.
  Then the  attraction of 14oz. of sulphuric
     acid and a pound of water or 14 oz.
     of water, and 1 lb. of sulphuric acid
     would be   .     .     •     •     •     1
   That of 12 oz. ofcsulphuric acid and
            1 lb. of water or
          12 oz. of water
            1 lb. of sulphuric acid     .     2
   Thus also the affinity of 20 oz and 12oz. of sul-
phuric acid, would  be the same for a lb of water.
So that we may safely conclude that the real law is
as follows, namely, that chemical affinity encreases
between any two substances, in proportion as the
ratio in which they  combine, differs from  that ra-
tio of combination at which the attraction is at a mi-
nimum.
   There can be no doubt that such a minimum
exists; for we know that a few drops of water, and 
   100       *    jin Enquiry, Hd
   a pound of sulphuric acid, as well as a few drops
   of sulphuric acid and a pound of water, both adhere
   more strongly than equal quantities;  hence there
   must be an intermediate point at which the attrac-
   tion is at a minimum ; again, we do not pretend to
   say, in what ratio the affinity encreases, whether it
   be in the duplicate or triplicate ratio of the degree
   of variance  from that proportion constituting a mi-
   nimum.
     This view of the subject leads us into the fol-
   lowing paradox ; that any repulsion  between two
   bodies less than  infinity, may be converted into
   any  attraction, less  than infinity, by making the
   ratio in which they combine infinitely to vary from
   that ratio of combination at which the minimum
   of affinity would take place.
      It may not a little contribute  in  enforcing  the
   position here taken to point out the probable way,
   in  which  this  great  Philosopher  fell  into this
   great error—we would explain it thus ;  it is with
   chemical combinations, as is  the case with other
   natural phenomena, that in proportion as  an opera-
   tion is common, or its ingredients familiar, to  us
<■'   we do not  regard it with as much pleasure, or in a
   philosophic point of view ;  thus it is that chemists
   too  frequently forget the chemical agency of wa-
   ter; this we have no doubt was the case with Berthol-
   let ; he found that the less the quantity of water in
   sulphuric acid, the greater the difficulty of separa-
   ing it; that the difficulty of separation increased, in
   proportion as pure sulphuric acid was added,  be-
   cause he plainly saw it amounted to the same thing 
                An Inquiry, He.            101
as the water decreases.  Well then,  said he,  as
the attraction in this case, is increased by adding
pure sulphuric acid,  as sulphuric  acid  is  mat-
ter, therefore  it is increased by adding matter;
and in proportion to  the quantity  added too; it
was by such a train of reasoning,  that Berthollet
was induced to frame this law, and  no doubt, he
supposed it of as much importance to chemistry, as
an analogous one discovered by Newton, is to tho
explanation of the motion of the  heavenly bodies;
thus it is perceived that  Berthollet  never thought
of the water; never thought, that, while he was pro-
ving  one law  by  adding  sulphuric  acid that he
might, with equal propriety, have demonstrated its
contrary by increasing the water.
O 
ON MURIATIC
                    AND

OXY-MURIAT1C ACIDS,  COMBUSTION,

                   he. &c.

By  Thomms D. Mitchell, M. D.   Fellow of
  the Academy of Natural  Sciences of Philadel-
  phia, Honorary Member ofihe Columbian Che-
  mical Society of Philadelphia. He.
 ON  MURIATIC, AND  OXY-MURIATIC
                  ACIDS.

  The nature of these acids has been the subject of
frequent investigation.
  I will not attempt to enumerate all the theories
which have prevailed on this subject.  Many years
ago, when phlogistic chemistry was more  preva-
lent, Mr.  Scheele supposed that muriatic acid was
a compound of oxy-muriatic acid and phlogiston,
and that the former was procured by deprivingmu-
riatic acid of the latter.   Hence the name de phlo-
gisticated muriatic acid. If we examine the grounds
on which these conclusions were founded, they ap-
pear to be, chiefly, a desire to establish the exis- 
       On Muriatic and Oxy-muriatic Acid.   103
tence of phlogiston, as a principle of inflammabili-
ty.  This will be evident  in  the following lines.
" When muriatic acid is dephlogisticated with as
much force as possible, it attracts phlogiston, with
great avidity, dissolving metals  by its affinity for
their phlogiston, and tiius uniting the inflammable
principle to  itself resumes the ordinary  form  of
muriatic acid." Again, " The phenomena -attend-
ing the  inflammation  of metals  in oxy-muriatic
acid, proceed from the great affinity of this acid
for phlogiston.  Marine acid which contains phlo-
giston as one of its component parts, must neces-
sarily have  little or no effect on  the metals which
retain their principle of inflammability, very obsti-
nately."*
   Now from all this it is abundantly evident, that
Scheele's theory of the nature  of muriatic acid
arose from his  firm belief in the existence of phlo-
giston as the inflammable principle.    So tenaci-
ous are some men of a favorite theory, that in or-
der  to support it, they are willing to make every
thing else subservient to that end.
   Mr. Davy has lately investigated this subject and
his conclusions are essentially the same with those
of Scheele.   He has appeared the champion of the
Phlogistic system and has endeavoured  to disco-
ver hydrogen in almost every thing.
   But how  does he support his opinions or rather
the opinions he advocates ? I answer; by storm-
ing with all  the fury of his Galvanic Battery,  the
* See Dobson's Encyclopedia. 
104  On Muriatic and Oxy-muriatic Acid.
fair edifice of Lavoisier :  an edifice, which had its
author lived to complete it, would have defied the
attacks of its enemies forever.
  If the theory as first given by Scheele and now
supported by Davy, be true, the former deserves
the credit of having maintained it more ably than
the latter.  He has attempted to  support it  in a
manner,  which would, at first view, appear quite
satisfactory.   But as  his premises  are false, his
conclusions  must be incorrect;  for he has taken
as granted, that which has  not been proved,  viz.
the existence of phlogiston.
  Mr. Davy certainly discovers much assurance
when he boldly sets up  his judgement in  opposi-
tion to that of thousands, and that too on obvious
points.  He tells  us " that chemists are mistaken
in supposing that muriatic acid gas contains  wa-
ter."  Now for this assertion, he has no proof ei-
ther in philosophy or  fact.
  " It has been said," says Davy  " by chemists,
that when oxy-muriatic acid and ammonia act on
each other, water is formed," but from experiment,
I am certain this  is not the case," and what is the
experiment by which  the ignorance of other che-
mists is to be so ably displayed ? it is this ;  *' when
about 15 or  16 parts of oxy-muriatic acid  gas are
mixed with from 40 to 50 of ammoniacal gas, there
is a condensation  of the whole of the acid  and al-
kaline gasses, and from 5 to 6 parts of nitrogen are
produced; and the result is dry muriate of  ammo-
nia." 
     On Muriatic and Oxy-muriatic Acids.   105
  But,  I ask, how does this furtile  experiment
prove that water is not formed by the hydrogen of
the decomposed ammonia uniting to the oxy-muri-
atic acid ? what becomes of the hydrogen if it does
not combine with the oxygen, and thus in the form
of water exist in the mur. ammonia ?  will we be
told, as  we have been heretofore,  that the hydro-
gen united to the oxy-muriatic acid to form muri-
atic acid ?  the position is absurd, and is at best
merely a conjecture, as such an union has not been
demonstrated.  It  is more plausible, that the hy-
drogen  and  oxygen gasses  should have  com-
bined to form water.   According to Mr. Davy's
experiment,  hydrogen  has  disappeared, and it
is sufficient for us to believe that  it has entered
into combination  with  the  oxygen  of theoxy-
muriatic acid and that it  exists in the state  of
water in the  salt  produced.   This experiment,
therefore, is  far  from disproving the   compound
nature of oxy-muriatic acid,  and it is in my opini-
on, the best proof that has been adduced, since all
else is wild conjecture. Mr. Davy, indped asserts
" that no substance known to contain oxygen can
be procured from oxy-muriatic  acid."
   But in every case where metals are acted upon
by oxy-muriatic acid, muriates are formed.  Now
I ask, whence comes the oxygen in an oxyde of
gold, combined with mur. acid, after combustion
in oxy-muriatic acid, if not from the oxygen of
the latter ? can it proceed from the muriatic acid ?
certainly not, since this acid is  not capable of act-
ing on gold. 
 106   On Aluriatic and Oxy-muriatic Acids.
   That oxy-muriatic acid should be a simple sub-
 stance appears to me as ridiculous as it is untrue.
 How does Mr. Davy evade the common opinion
 of the decomposition of this acid by light and other
 means ? why to be sure, he tells us that something
 must always be present to furnish hydrogen and
 thus  to form muriatic acid.  But this rests alto-
 gether on supposition and has not been proved In-
 direct experiment.
   After all that has been said of theory, and its fal-
 lacy,  it may appear strange that I should  attempt
 to offer further conjeetures on this subject.   But
 there is a period in the philosophical investigation
 of every subject, at  which experiment fails to be
 useful.   And it is sufficient to deduce our opiili-
 ons from correct examinations of experiments that
 have  been already performed.
   That Lavoisier was strictly correct, when he as-
 serted that oxygen was a substance common to all
acids, I firmly believe. This great genius has giv-
en us a term, merely on conjecture, which is per-
haps less exceptionable, than some have imagined,
viz.  muriogen.  Mr. Berthollett has also suppo-
sed the existence of this substance and has hinted
at the probability of its metallic nature.
  The illustrious author of all that is true in  che-
mical science, declared, nearly  twenty  years  ago,
his belief in the existence of oxygen in all the acids,
in which it had not then been demonstrated.   Nor
was this all; his mighty mind with heroic energy,
looked forward to the day when the earths and al-
kalies should be found to consist of oxygen and a 
     On Muriatic.and Oxy-muriatic Acids.  107
metallic  base.  Reasoning from what he knew, he
wisely conjectured that both earths and alkalies
were  metallic compounds.  Why  did Lavoisier
suppose  that muriatic acid contained oxygen, but
on account of its known existence in other acids ?
and did he believe the base of the earths to be me-
tallic ? he founded his belief in their failure to unite
with oxygen ; knowing that a metal in its highest
state of saturation with oxygen, could not  readily
combine  with  more oxygen, he rationally con-
cluded that  the earths and alkalies had a metallic
base so completely saturated with oxygen, as to be
incapable of combining further with this elemen-
tary substance.
  What have the researches of Davy effected with
regard to the  alkalies ? they  have only  confir-
med the conjectures of Lavoisier and have thus
proved him to be one of the most illustrious cha-
racters the world has ever produced.*  Now that
his anticipations respecting the earths  and alkalies*
have been realized, shall we disdain to attempt the
proof of what he has asserted of the muriatic acid *
surely not.  The day is yet to come when the sup-
posed existence of oxygen in muriatic acid will be
rendered certain.  There was no  better reason a
few years past to believe the earths to be oxydes,
than there is at the present day for supposing mur.
acid to contain oxygen.   The earths,  and alkalies
retained the oxygen in their composition so close-
ly that no power was able to separate them until
the aid of Galvanism was invoked.
  * I am not certain that the alkalies have been decomposed ; m v
doubts arise from having heard some ingenious remarks on this sub-
ject by W. Hembell 
 108  On Muriatic and Oxy-muriatic Acids.
   And though the base of muriatic acid may be so
 intimately blended with oxygen as to  resist  our
 past attempts to overcome their powerful attrac-
 tion for  each other,  we may  look forward  with
 confidence to a day not very distant, when like the
 earths, this acid shall be found to consist of oxy-
 gen and  a metallic base.   That day whenever it
 shall arrive, will add new tributes of respect to the
 memory of him, who, while opposed by  his ene-
 mies on  all sides,  boldly withstood  their attacks
 and proved himself a host.
   It is generally true, that acids are, weak or pow-
 erful in their action on metals, in proportion to the
 force with which the oxygen of such acids is retain-
 ed by their bases.  Thus the aqua regia in which
 the oxygen is held but slightly, is the  solvent of
 gold.  Sulphuric acid will not act on this metallic
 body, and it is known to retain its oxygen, firmly.
 Muriatic acid, in a state freed of water as much as
 possible, will scarcely act on  any of the metals,
 and this is owing most probably to its oxygen be-
 ing so closely combined with  the base,  that no
 force has been able to separate  it.
   The real base of muriatic acid, we believe, will
 prove ultimately, metallic.   For convenience, we
 shall name it muriogen.  This is so  intimately
united to oxygen, as to prevent us from detecting
it in a separate state; and is there any thing won-
derful in  this ? true,  we have never seen muriogen
as the metallic base of muriatic acid,  nor have we
ever found this acid to  contain oxygen. 
     On Muriatic and Oxy-muriatic Acids.   109
   But in these respects it is exactly on a par with
potash.  Who ever saw the substance potassium,
or was certain of its existence until the powers of
a Galvanic battery brought it to our view ? or who
demonstrated the existence of oxygen in the earths
until by Mr. Davy's experiments it was rendered
certain ? Let no one deny  that which by analogy
is brought  within the sphere of probability, and
which  is not far remote from certainty.
  It would appear more consistent to use the terms
muriatious and muriatic,  in place of muriatic and
oxy-muriatic acid.  These we suppose to differ
merely in the quantity of oxygen united to the
base, as is the case with other acids.
  The peculiarities of the acid when its oxygen is
in excess, may and probably do arise from the na-
ture of the base.   This is by no means repugnant
to reason. Potassium by union with oxygen, is said
to form the  peculiar substance called alkali.   But
it is possible that  it may  be  converted into  an
acid by a still larger combination with oxygen.
  Phosphorus has probably a metallic  base uni-
ted to  oxygen, constituting an oxide.   By com-
bination with oxygen, it may be changed into an
acid, the phosphoric.
  Thus, in  conformity with the remarks now of-
fered, the compound nature of oxy-mur.  acid is
quite reconcilable ;  and  to a candid inquirer, the
causes here  assigned for the peculiarities of oxy-
mur. acid will appear to be founded at least in phi-
losophy, if not in fact.
                      P 
 110  On Aluriatic and Oxy-muriatic Acids.
   But it may be proper to say something further
 on the supposed decomposition of muriatic  acid
 into oxy-muriatic acid and hydrogen gasses.   It
 is more than probable that water and not the acid
 was decomposed.   The  hydrogen of the water
 might thus be evolved,  while oxy-muriatic acid
 might be formed by the union of the disengaged
 oxygen gas with the muriatic acid.
   To admit Mr. Davy's speculations to be correct
 we must seek  for a new rationale to explain  the
 production  of  oxy-muriatic  acid from  oxide of
 manganese, mur. soda  and sulph. acid.   If these
 speculations be indeed well founded, I can see no
 advantage in the oxide of manganese in this pro-
 cess ; for not only the mur. soda must be decom-
 posed, but also its muriatic acid,  The  muriatic
 acid being thus decomposed, would give rise, ac-
 cording to Davy, to the oxy-muriatic acid; and
 the only possible use of the  oxide of manganese,
 must be to combine with the hydrogen of the mu-
 riatic acid, to form water.
   Such a rationale in the room of one that is sim-
ple, and probably correct, appears extremely ridi-
culous. The production of oxy-muriatic acid from
the sources just  mentioned, is a sufficient  ground
for rejecting the hypotheses of Mr. Davy on  the
nature of muriatic acid.  Nature does not pr; tract
her course  in the accomplishment of an end that
 can be attained by a direct route.   And there is
no necessity for complicating phenomena that  are
in themselves perfectly simple. 
     On Muriatic and Oxy-muriatic Acids*   111
  A few more remarks, and I shall close.   Mr.
Berthollet,  after repeated experiments, has  pro-
cured the  mercurial salt,  calomel, by passing a
quantity of oxy-muriatic acid gas over mercury.
The plain,  common mode of explaining this pro-
cess, is  founded on the compound nature of oxy-
muriatic acid.  That  is to  say, the  oxy-muriatic
acid gas was decomposed, its  oxygen  uniting to
the mercury,  forming an oxide, which, in combi-
nation with the muriatic acid,  formed a muriate.
But what says  Mr. Davy ? why, that hydrogen
must have  combined with the oxy-muriatic acid,
to form muriatic acid.  But let us  examine this
point a little,  and that too with Mr. Davy's own
scale.
  Whence, then I ask, is derived  the hydrogen to
combine with the oxy-muriatic acid gas ? is it from
the mercury ? how can this be, since we are told
that the very  circumstance  of its supposed incom-
bustibility, depends on its want of hydrogen.   All
the industry of  Mr. Davy   has not been able to
demonstrate  the existence of hydrogen in this
metal, and it is only by analogy, that he is able to
render it even probable.
   But it is  said that oxy-muriatic  acid gas, like all
other gases, holds in solution, a large quantity of
water, wnich, by  decomposition, would furnish
hydrogen.
   This, to  be sure, if hydrogen must be obtained,
is as good a mode for procuring it, as we can ima-
 gine.   But  perhaps  this  last resource, as we 
 112  On Muriatic and Oxy-muriatic Acids.
 hope to make apparent, will not be able to furnis)
 the necessary quantity.
   No man will pretend to say, that more than one
 half of the bulk of oxy-muriatic acid gas,  is water.
 Now how are we to estimate the component parts
 of muriatic acid, according to Mr. Davy ? it would
 appear  from his  experiments,  that it consists of
 about 9 or 11 parts hydrogen in 20, the remainder
 being oxy-muriatic acid.  So that in order to form
 muriatic acid,  from oxy-muriatic gas, we  must
 add to the latter nearly an equal quantity of hydro-
 gen.   Well, let us  suppose that Mr. Berthollet
 added to 1 part of mercury, 20 parts of oxy-muri-
 atic acid gas, imagine  also that this oxy-muriatic
 acid gas contained 10 parts of water.   From this
 not more than 2 parts of hydrogen could be obtain-
 ed by decomposition, and  we are expressly told,
 that no  combination of hydrogen and oxy-muriatic
 acid gas can take place, except they are presented to
 each other in quantities nearly equal.  But suppose
 that oxy-muriatic acid gas  should not contain \ th
 its  bulk of water, the case would then be much
 worse  for  our opponents.  The subject  how ever
 is easy of comprehension, and the fallacy of the an-
 cient conjecture,  so  warmly  received in  the pre-
 sent day, must be obvious.  Delusive experiments,
 by means of an agent, whose real mode of opera-
 tion is not known to us, may have rendered some-
 what probable, the simple nature of oxy- muriatic
 acid.   But errors like these, however masked they
 may be for a moment, soon vanish before  the full
blaze of truth.  Let us, like Lavoisier, reason be- 
                Of Combustion.            \ 13
fore  we  decide;  for although the senses  may
sometimes induce us to concede to the truth of a
seeming fact, yet even that evidence should not be
paramount to reason.
OF COMBUSTION.
  THERE is no theory on this subject which 1
can entirely embrace.
  Lavoisier defines combustion to be the decom-
position of oxygen gas by a combustible body.
But  I am of  opinion that in every case in which
oxygen combines chemically with another body,
the process of combustion is essentially carried on.
That is, heat and light are evolved, and the body
is changed.   The process may be slow or rapid;
the heat and light may be evident or they may fail
to be cognisable to the senses; but this is no ob-
jection to my  position.
  In the  formation of every oxide, a portion of
caloric must necessarily escape, yet oxides are of-
ten produced without any sensible  evolution of
heat.
   That light, as well as heat, is a constituent of all
bodies cannot be disproved.   Of course, if this be
true, no existing theory respecting the production
of light and heat in combustion, can be correct.
   Dr.  Thomson has offered  a modification of La- 
114            Of Combustion.
voisier's theory on combustion.   He supposes the
combustible to yield the light, while the suppor-
ter affords the heat. In fact, I am of opinion that this
is more remote from truth than Lavoisier's, which
by supposing light as well as heat to proceed from
the supporter must admit the existence of light in
oxygen gas.  Light and heat I conceive to be
constituents of every supporter  and of every com-
bustible.
  It is said that light has not been found to exist
in  oxygen  gas.  But I ask, whence proceeds the
vivid and profuse light in the rapid combustion of
a small piece of iron in oxygen gas, if not chiefly
from the latter?  The following  fact, from Parke's
Chemical Catechism, seems to prove that atmos-
pheric air contains light.  Some time ago a soldier
in  the French army found that heat was produced
by the condensation of air in  an air gun sufficient
to  inflame a piece of spunk.  This experiment has
lately been repeated before the National Institute.
If the air be very rapidly  compressed, heat is dis-
engaged by the first stroke of the piston.   If the
end  of the pump be  furnished  with a glass lens
which admits of the inside  being seen, at the first
stroke of the piston, a ray of vivid brilliant light
will be perceived.
   The quantity of light and heat differs in different
bodies.  Hence it is unphilosophical to derive all
the light from one source only.  I am fully per-
suaded that the light and heat  given out in com-
bustion, ought not to be attributed to the combus- 
                 Of Combustion.            115
 tible on the one hand, nor to the supporter on the
 other.
   There are cases, undoubtedly, in which the oxy-
 gen gas affords the greater part of the light in com-
 bustion.
   We  have incontestible proof that oxygen  gas
 contains light, from the effects of light on metallic
 oxides.  It combines with the oxygen and flies off,
 thus effecting what  is called  deoxidation.   Now
 we know that  light and heat have similar effects on
 metallic oxides,  that is to decompose them.  When
 this is done by heat, it is universally admitted that
 the caloric enters into combination with the oxy-
 gen and fiies off in the form of oxygen gas ;  hence
 caloric  is said to be  a component part  of oxygen
 gas.  Why not admit the same of light ?  the
 oxygen in an  oxide  is known to contain a portion
 of caloric, as is  proved by Lavoisier.  We effect
 a decomposition of the oxide, only, by an increase
 of this caloric.  So  with regard to light; there is
 undoubtedly a portion of light in every oxide, and
 it can only be by an increase of this light, that  the
 oxygen is enabled to quit the oxide.  There is pro-
bably no combination of oxygen gas with any body
in which all its coleric escapes;  the same may be
true of light.  Much more might be said to show
that light is a constituent of oxygen gas, but it will
be objected, that we cannot demonstrate its exis-
tence. The same is equally true of heat; we know
little of  either, except by their effects.
  There are many  cases I  grant in which oxygen
gas is largely consumed without evolving  much 
 116            Of Combustion.
 light.  But there are instances, also in which ox-
 ygen gas  is decomposed in  abundance, without
 the production of much sensible heat.
   I believe that in manufactories of saturnine pre-
parations, as miniun, massicot &c. there is as cer-
tainly a combustible process carried on, as in the
burning of a candle.  True there is no obvious light
evolved, nor is there much  heat except from the
fire employed in the process.  The decomposition
of the oxygen gas is so gradual, that heat is not de-
rived|from this source in large quantities, yet it must
be evolved in some degree, and there must also be
an evolution of light.  But in general, where the
oxygen gas is rapidly decomposed, not only heat,
but light escapes in a sensible form.
   Lavoisier speaking of oxygen gas and its decom-
position  by means  of mercury  and iron, says,
 " that in the one case,  it  must be considered as a
kind of gradual combustion ;  whereas in the other
viz. the combustion of iron, the process is extreme-
ly rapid  and is attended with  a brilliant flame."
Again he  says,  "as calcination  sometimes lasts
during several days, the  disengagement of light
and caloric, spread out in a considerable space of
time, becomes extremely small  for each particular
moment of the time, so as not to be perceptible."
   I therefore dismiss this part of my subject, firm-
ly persuaded, that the light in combustion, as well
as the heat, proceeds partly from the supporter and
partly from the combustible.  And in no case,  do
I believe,  that the light or the heat proceeds solely
from either. 
Of Combustion.            117
  Milton, speaking of light, says thus :
     --------------------Before the sun,
     Before the heav'ns thou wert, and atthe voice
     Of God, as with a mantle did invest
     The rising world of waters, dark  and deep.
  There is so much analogy between  combustion
and acidification,that I cannot  pass over it without
a few remarks.
  In fact both appear to be only modifications of one
grand operation, by which all  the forms of matter
were produced ; I mean the combination of oxy-
gen  with an  original base, which  was probably
metallic.  In acidification  we  have a  base so  call-
ed and in many cases, or I should say in all cases,
oxygen, which in union form an  acid.  In like
manner in combustion, we have a base or body ca-
pable of combustion, or of decomposing under
certain  circumstances,  oxygen  gas.  We have
likewise oxygen gas, or something which contains
it.   In fact, the production of all acids, is proba-
bly by a species of combustion.  When  treating
of the term oxygen in the remarks on acidity, I
proposed to say something on the impropriety of
that  word as applied to chemistry in its literal
sense.   We have said that oxygen signifies to be-
get or form acid ; but in some cases of combustion
no acid is  formed and the result  is often an oxyde.
   As combustion requires the presence of oxygen,
without which, flame  cannot  be produced, there
would be  no propriety in calling this  the principle
of inflammability, if such a term were admissible.
   On this subject, however, I have made some
remarks in another essay.             Q 
ON  THE  PRODUCTION
  Of Sulphuretted Hydrogen by the Action of Black
   Sulphuric Acid, Diluted with  Water  on  Iron
   Nails.   By John Manners M. D.


     HAVING a short time ago occasion to pro-
 cure some hydrogen gas for some experiments in
 which I was engaged, I poured some sulphuric
 acid which had been coloured black by the falling
 in of a cork about six months before, diluted with
 five  or six times its weight of water upon some
 clean cut nails. But'from the  hepatic odour emit-
 ted,  I perceived that the gas generated  was not
 hydrogen, but sulphuretted hydrogen.   I applied a
 silver piece to the tube of the syphon from which
 the gas was emitted, and found it immediately
 blackened or converted into a sulphuret.   I  also
tested it with the nitrate of silver and acetate of
lead which were also blackened. 
 On the Production of Sulphuretted Hydrogen.  119
   In what manner are we to explain the rationale
 of this experiment? Does it not prove in the^r^
 place, contrary to the opinion of  Dr.  Thomson
 and some other chemical philosophers of high re-
 spectability, that the combustible matter of the cork
 was capable of decomposing the sulphuric acid, at
 the ordinary temperature of the atmosphere,  and
 robbingitof a portion of its oxygen ? There is little
 doubt that the combustible matter of the cork ab-
 stracted so much oxygen from the  sulphuric acid
 as to  convert it (or a part of it at least) into sulphu-
 rous acid; and perhaps that of a weak degree of
 oxygenation. That by the action of the acid upon
 the iron, the water was decomposed, the oxygen of
 the water, united with the iron and formed oxyde
 of iron;  which was immediately dissolved by the
 acid,  and formed sulphate of iron;  while a part of
 the hydrogen of the water, in its nascent state, seiz-
 ed upon the oxygen of the sulphurous acid,  and
 formed water; by which  the sulphurous acid was
 was  converted into  sulphur.   While the  other
 portion of the nascent hydrogen, dissolved the  sul-
phur to form sulphuretted hydrogen.
   Or shall we say that the sulphuric  acid  when
 diluted with water in acting upon the iron,  gave
 out a portion of oxygen to oxydize the iron, while
 the sulphuric acid thus robbed of a portion  of its
 oxygen, seized upon the oxygen of the water to be
 re-oxydized, and united with the  iron to form
 sulphate of iron: while a part of the hydrogen in its
 nascent state,  robbed the sulphurous acid of its
 oxygen  and formed water, while the sulphurous 
120         On the Production He.
acid was converted into sulphur.  Another part
of the hydrogen in its nascent state dissolved the
sulphur to form sulphuretted hydrogen ?
  Or shall we go still  further and  say  that the
Cork abstracted all the oxygen from  a portion of
the sulphuric acid, and converted  it  into sulphur.
That by the action of the remaining acid &  water
on the iron, the hydrogen generated  (as explained
in one of the before mentioned ways) in its nascent
state dissolved the sulphur and formed sulphuret-
ted hydrogen gas ?
   The first of these explanations is most probably
correct. 
ON THE
   EMISSION OF OXYGEN GAS BY
                 PLANTS.

By George Ferdinand Lehman.   Vice Pre-
  sident of the Columbian Chemical Society,  Ho-
  norary member of the Medical Society of Phi-
  ladelphia, He.

    CHEMICAL philosophers, have  long con-
sidered the phenomena of vegetables interesting,
and worthy of inquiry.   Many of  the  most emi-
nent in this science have exercised their genius,
and abilities in discovering the nature and pow-
ers of plants.   Among  the  most  important ques-
tions to be elucidated, was  the manner in which
plants  afforded  oxygen  gas to the  atmosphere.
The different opinions which have been offered on
this point; and the doubt which at present exists
in the minds  of many, repecting the real way the
air is purified; are the reasons why, I make these
observations.
  The ingenious Dr.  Ingenhousz believed that
vital air,  was given out by plants by elaboration.
This idea, which did not satisfy the mind of Sir 
  122           On the Emission of
  Benjamin Thompson, induced him to offer a theo-
  ry, in which he says that all the air which comes in
  contact is inhaled by plants, and while its nitrogen
  and carbonic acid gas afford  them  nourishment,
  the oxygen is completely set at liberty.  These
  notions however, were considered by Fourcroy as
 erroneous.  This celebrated man, who shines like
 a comet in the firmament of chemical science, has
 given us a simple explanation of  this process.  It is
 not however, complete.  " Hitherto the art of che-
 mistry  has arrived at the knowledge of no means
 of decomposing water, but by  combustible sub-
 stances, which take from it its oxygen.   We are
 unacquainted with any capable of attracting its hy-
 drogen, aud setting  its  oxygen free.  It would
 seem however, that nature has instruments for ef-
 fecting  this inverse manner of decomposing water:
 the leaves of vegetables struck by the rays of the
 sun appear to decompose water,  by absorbing its
 hydrogen, and disengaging its oxygen in the form
 of vital  air.  This we may presume to be in part,
 the mechanism  of vegetation, of the formation of
 oils, and of the renovation of the atmosphere."
   This assertion is justfied by experiment; but I
 think it highly probable that plants in their natural
 state, oxygenize the atmosphere both by the de-
 composition of water,  and  impure air:  and  al-
though  experiments say that oxygen gss is given
out by them  in  such  situations that no air could
be absorbed, it only exhibits the wisdom of nature,
in having resources against such necessities.
  Animals confined  in a vessel after a certain 
             Oxygen Gas by Plants.        123
time perish, in  consequence of having consumed
all the vital air ; if we introduce the leaves of plants
in the same vessel, inverted over a quantity of wa-
ter after a short  period animals will exist in it.
As the solution of this  fact is of considerable im-
portance, I will dwell on it for a few minutes.
   It is evident, that the vital air is replaced through
the instrumentality of the leaves ; but how is their
presence  necessary  to  its  restoration ?  Do the
leaves elaborate oxygen gas ? Do they absorb the
air of the vessel, and eliminate vital air ? or, is it
owing to the decomposition of water ? It would be
inconsistent with sound reason,  to suppose that a
few leaves couid generate enough oxygen  gas  by
elaboration to fill a vessel and support several ani-
mals.   If this were the case, a  few  trees  would
certainly be sufficient to purify a whole city.
   It is replenished with oxygen gas, by the de-
composition of the water, and impure air.
   If Thompson's theory of itself were correct, as
animals never exhale the whole of the oxygen  ta-
ken  into  the lungs during  inspiration, this gas
would gradually be decreasing and universal death
would be the consequence.
   Are there any reasons, besides the improbabili-
ty of the above solutions, which render it just, for
us to suppose that the oxygen gas in the vessel, is
owing to the separation of the constituent parts of
the water, and impure air ?  The decomposition of
this fluid is obvious from its bulk being diminish-
ed, in proportion to the quantity  of gas eliimnated,
and that the foul air of the vessel is also changed, 
124         On the Emission, He.
is evident from oxygen gas assuming  its place.
In order to satisfy myself more particularly on this
point, I placed a mouse under a tumbler inverted
over water.  After the oxygen of the air was all in-
haled it died.   In  this state, filled with impure
air, I introduced under the glass a few  leaves of
aurantum (orange) over a  given portion of water,
and exposed it to the sun.  In six hours, I placed
another mouse in the vessel, and it lived.  I per-
formed this experiment a second time without the
mouse,  and satisfied myself that the vessel con-
tained  oxygen gas.   Upon examining the water,
it had diminished.  Aquatic plants, or those which
grow best in moist and wet situations afford more
oxygen gas,  than  those congenial to dry places.
This cannot be solved unless we  admit, that as
more water is in the aquatic plants, more oxygen
must of course be rejected.   This has been con-
firmed by Priestley, and Archer proves  that the
Salix Viminalis affords more vital air from a moist
place (which he observes is well suited to it) than
the same kind of plant, does from a dry situation.
Oxygen gas  will be given out by plants when no
water apparently  is presenr.  This must  occur
from the decomposition of impure air, and mois-
ture of the atmosphere ; for an air perfectly  dry
would be fatal to life.
  Reflecting on what has been said, we  cannot but
admire the simplicity and  uniformity, which per-
vades nature ; here is one of her most useful pro-
cesses, animals, and plants  mutually supporting
each other. 
ANALYSIS
                    OF

 MALACHITE,  OR GREEN CARBONATE
      OF  COPPER OF PERKIOMING,
             PENNSYLVANIA.

 Bv Thomas D. Mitchell, M. D.   Fellow of
   the Academy of Natural Sciences of Philadel-
  phia^ Honorary Member of the Columbian Che-
   mical Society of Philadelphia. He.   *

   THE mine at Perkioming, has long been eele.
 brated, not only for its valuable contents, but like-
 wise for the numerous chemical and philosophi-
 cal disputes,  to which  it has given birth.  The
 ores of zinc, contained in it, have excited more at-
 tention, than any other of its  contents, and have
 been the subjects of frequent analysis.
   The green  carbonate  of copper is found at the
 same mine in large quantities, and no doubt, could
 be  worked to great advantage.  This, I believe,
 has never been analysed, or if examined, the ana-
lysis has never been published.   I have, therefore,
                      R 
126            Analysis, He.
thought it of some importance to  investigate  its
contents.   For this purpose, I pulverized 5ij of
the ore, and subjected it to the action of a mixture
ofgiofsulphuricacid,and§ij ofwater. These being
put into a bottle, the whole was accurately weigh-
ed, for the  purpose of ascertaining the quantity of
carbonic acid in the ore,  according to the mode
pursued  by Accum.   The action having  ceased,
the bottle was again weighed, when it  was found
to have lost 30 grains.   I then poured the contents
of the bottle on a filter, and the residuum amount-
ed to 68  grains.
  This residuum consisted of Quartz and siliceous
earth.
   Into the fluid, I then immersed pieces of polish-
ed iron and obtained a precipitate of the brown
oxide of copper, amounting to 15 grains.
   Thus  it appears from  the  experiments made,
that the g»een carbonate, weighing      120 grs.
   contained of carbonic acid   30 grs.
   quartz and siliceous earth   68 grs.
   brown oxyde of copper     15 grs. = 113 grs.
           Loss in the process  .    .     7 grs. 
THOUGHTS
On the Expediency of Changing parts of the Che-
   mical Nomenclature.  By Franklin Bache,
   Vice President of the Columbian Chemical So-
   ciety.

     IT  is well known that the nitrous oxide is
capable of uniting  with the alkalies, and forming
peculiar  salts, which Mr.  Davy has proposed to
call nitroxis, but which are generally known by
the name azotites ; this latter term we conceive to
be in every point of view, exceptionable, and a de-
parture  from  the  original simple  plan of our
Chemical nomenclature.
   When but two oxides of nitrogen were known,
which  were capable of  forming salts, no greater
extension of the  Lavoisierian  plan was necessary
than to afford  appropriate  terms for the salts of
those two oxides ; they were distinguished by the
terms nitrous and nitric acids,  and  their salts by
the words nitrites  and nitrates; at  that time, it
was not anticipated that there was yet another ox- 
 128              Thoughts, He.
 ide of nitrogen capable of forming salts;  but as
 soon as it was discovered, a  name  should have
 been formed for it, on the original principle, that
 is, by another variation in the same name.   Thus
 we should propose to  call this oxide which has
 been lately discovered  capable of forming salts, in-
 stead of nitrous oxide  nitral acid, and its salts ni»
 trotes instead of azotites.
   But as the nitric oxide has not heretofore  been
 rendered  capable  of forming  salts,  it remains  a
 question, whether it would be expedient to  change
 that term also : upon the whole, we think it would;
 since it would be the means of rendering the names
 of the oxides of azote uniform, as it respects the
 manner  of their formation.  Here, therefore we
 should propose  the term nitril acid, instead of ni-
 tric oxide. According to this plan then we should
 have.
   1.  The  nitral acid, forming salts called nitrotes,,
 instead of nitrous oxide, or oxide of azote, form-
 ing salts called azotites.
   2.  The nitril acid, now called nitric oxide, the
 salts  of which (should it be discovered capable of
 forming them) might be called nitrutes.
   3.  The nitrous acid  forming nitrites ; and
   4.  The nitric acid forming nitrates.
   To bring the whole matter under one view, we
 should have the nitral, nitril,  nitrous and nitric
 acids, forming salts, distinguished by the names,
 nitrotes nitrutes nitrites and nitrates ;  by this ar-
 rangement we should avoid, in expressing a set
of salts, the irregular term azotite. 
                Thoughts, Hv.              129
  It may here be asked, with what  propriety we
can give to substances, which have not all the cha-
racteristics of acidity, the name acids ; we answer,
that as long as a body agrees with the class of acids
in a most important particular, such  as its capaci-
ty for forming salts, we may be justified in depart-
ing from the strict definition of an acid by  refer-
ring it to that head, when such a departure will be
attended by a simplification  of the  chemical no-
menclature.   In fact we think no evil would arise
should we even define an acid to  be any oxide ca-
pabable of forming salts.
  Another point, in which we think the nomencla-
ture defective, is in the names given to the muria-
tic acid and its combinations with oxygen,  since
they are formed contrary to analogy.
  We shall propose to alter these terms in the fol-
lowing manner; thusfor muriatic acid, let us sub-
stitute the term muriatil acid, and call its salts mu-
riutes ; for oxymuriatic acid, the term muriatous
acid, calling its salts  muriites, and instead of hy-
peroxymuriatic acid, the name muriatic acid, dis-
tinguishing its salts by the term muriates.   There
can be no reasonable doubt but muriatic acid con-
tains oxygen, that consequently oxymuriatic acid
contains more of that principle than  muriatic acid,
and that  hyperoxymuriatic  acid contains   more
than either.   Under this view of the subject the
above arrangement cannot be objected to.
   We  have yet to  mention another instance in
which the principles of the simple Lavoisierian no-
menclature have not been applied, at least not ve- 
     130             Thoughts, He.
     ry happily; we mean in naming the salts formed
     by the super sulphureted and sulphureted hydro-
     gen gases ; these have been called hydrogureted
     sulphurets  and hydrosulphurets; the impropriety
t    of these terms was obvious to Mr. Kirwan; and
     we have to regret thst his substitution of heparfor
     the former, and hepatule for the latter, proved him
     less able to correct, than to detect error.  As these
     substances  no doubt contain oxygen, (for we in
     vain attempt  to refuse the  evidence  of analogy)
     which, should it be proved by experiment, it would
     necessarily follow that supersulphureted hydrogen
     would be that substance  which is combined with
     the less dose of oxygen, since its  only difference
     from sulphureted hydrogen is an addition of sul-
     phur ;  it is on this account we should wish to call
     the supersulphureted hydrogen, the hydro-sulphu-
     rous acid, and  its salts hydrosulphites ; while the
     sulphureted hydrogen, would be more properly
     named hydrosulphuric acid, and its salts hydro-
     sulphates. These alterations we feel confident will
     not be  objected  to  when  it  is considered what
     a  number  of terms  have  been  adopted to ex-
     press these substances without any attention  to
     analogy :   we  should hardly  dare to mention
     the various names  adopted  by  Chenevix and
     Berthollet;  in short we  are  surprised that any
     Chemist should adopt the termination  uret to ex-
     press a salt, that being the regular manner for ex-
     pressing combinations with die  simple combus:
     tibles. 
               Thoughts, He.              131
   But we have still a more material objection  to
the chemical  nomenclature,  as it now stands,
which to understand,  we must premise a few ob-
servations.
   That no acid will combine with any metal, unless
it be previously oxidated is a well ascertained fact;
it  is further known that a great majority of the me-
tals are susceptible of several degrees of oxidation;
to obviate the  difficulties which this circumstance
might otherwise have created, Dr. Thomson has
very judiciously proposed to distinguish them,
not by their colour (which circumstance is varia-
ble in the  same oxide)  but  by prefixing to the
word oxide the particles pro, deu, tri or per, ac-
cording to the degree  of oxidation, pro being pre-
fixed to an oxide oxidated to a minimum, and per to
one oxidated to a maximum : but we are surprised
that Dr. Thomson has not extended  his simplifi
cation of the nomenclature, to distinguish the salts
formed by the different oxides of the same metal:
thus two oxides of mercury are found capable  of
forming salts with  muriatic acid ; that salt which
contains the oxide, oxidated to a maximum is call-
ed the oxymuriate of mercury by Dr, Thomson,
that is, a combination of the  muriatic acid with
the peroxide of mercury; but we would ask, is this
properly named ? if so,  what shall we call the salt
formed  by the  combination of the oxymuriatic
acid with any oxide of mercury, should it ever be
formed, shall  we  call this an oxymuriate  also?
this would be confounding a variety of muriated
mercury with  a distinct species of salts, the oxy- 
 132              Thoughts, He.
 muriates; thus to admit such a terminology would
 be to create utter confusion.
   To avoid these difficulties we should propose
 the following plan ; let the different salts of the va-
 rious oxides of the same metal, be distinguished as
 the oxides themselves, that is,  by prefixing  the
 same syllables.  A ccording to this plan, instead of
 calling corrosive sublimate an oxymuriate of mer-
 cury, let it be known by the name of the permuri-
 ate of mercury; the per prefixed,  indicating it to
 be a muriate of the peroxide of mercury.  On the
 other hand calomel would be properly called pro-
 muriate  of mercury,  because it is a combination
 of the protoxide of mercury with muriatic acid;
 certainly by a person not well versed in chemistry
 the oxymuriate of mercury would be supposed a
 combination  of the oxymuriatic acid  with some
 oxide  of mercury, whereas no such salt exists.
   Should other oxides, besides the peroxides and
 protoxides, be discovered capable of forming salts;
 then according to the oxide  they contain, let them
 be distinguished by  the appropriate particles of
 that oxide.
   We might here object to Dr. Thomson's appli-
 cation of the particle per to oxides at a maximum of
 oxidation, without regarding whether such a maxi-
 mum constitutes them acids or not;  thus he calls
 the arsenic acid the peroxide of arsenic ; we should
 however rather apply this  prefix to  those oxides
which  condense  the greatest quantity of oxygen
without becoming  acids; in short we could wish
to consider the word oxide as a generic term, in- 
                Thoughts, He.             133
eluding under it oxides (properly so called) acids
and alkalies.
  We might here contend for the expediency of
affixing determinate names to a set of bodies which
are in every point of view interesting, we mean the
compounds formed by the earths and metallic ox-
ides with the alkalies; to these substances no defi-
nite names have been given;  The combination of
the  peroxide of copper with ammonia has been
calle^ both the ammoniate of copper and the en-
prate of ammonia.   The necessity of having some
precise rule for formingnames for these bodies must
be obvious; we should propose that all these com-
binations should be expressed by  changing the
termination of the alkali into ate; thus the fulmi-
nating of silver, a combination between the peroxide
of silver and ammonia, might be called the ammo-
niate silver; Nor will we be accused of a want of
precision for omitting the word oxide in the name,
since metals equally refuse to  combine with al-
kalies as with acids, unless previously oxidated.
Use might also be  made here  of Dr. Thomson's
particles ; since some alkalies dissolve the protoxide
while they refuse  to  combine with  the peroxide
of thefsame metal.
  As connected with the subject we think proper
here to mention what we conceive a misapplica-
tion of terms in Dr. Thomson's work on chemis-
try.   Under  the head of oxymuriate of iron he
has the following words.
  " When a current  of oxymuriatic acid is made
to pass through water having the red oxide of iron
                       S 
 134             Thoughts, He.
 diffused through it, the oxide is dissolved though
 with considerable difficulty ; But Mr. Chenevix
 to whom we are indebted for this experiment has
 not examined the properties of the hyperoxymu-
 riate which must be formed during the process."
   Now we cannot perceive any good reason for be-
 lieving an hyperoxymuriate would be formed;  in
 short under no view of the subject would it be pos-
 sible. It certainly cannot mean that, since a muriate
 when itjContains a peroxide is called an oxymuriate,
 therefore an oxymuriate when it contains a peroxide
 must be called a hyperoxymuriate ; in fact it would
 be needless to conjecture what is meant.
   We make no hesitation in declaring as our be-
 lief that this substance  which Dr.  Thomson has
 called ah hyperoxymuriate of iron is nothing but
 the oxymuriate of the peroxide of iron ;  or rather
 the peroxymuriate  of iron,;  on the other hand,
 should the proposed alteration of the names of the
 muriatic acid and its combinations with oxygen be
adopted, it should be called the permuriite of iron,
 that is, a combination of the muriatous acid with
 the peroxyde of iron.
   We heartily wish the society  would take into
 consideration these misapplications of terms ;  more
 especially  as .they occur in a  class of bodies
 becoming every day more and more  important ;
 in fact every end intended by this  paper  will be
 fulfilled if we have demonstrated some irregulari-
 ties in the  present  nomenclature,  although the
 foregoing plan for  obviating  them  should not
 meet your entire approbation. 
V y  REMARKS



ON  PUTREFACTION.
By Thomas D.  Mitchell M. D.   Fellow of
  the Academy of Natural  Sciences of Philadel-
  phia. Honorary member of the Columbian Che-
  mical Society of Philadelphia, He.

     When an animal or vegetable loses what has
been  called its principle of vitality, it  necessarily
takes on a new form.  This change is  effected by
a process  called putrefaction,  which  is  nothing
more nor less than a  complete analysis of animal
and vegetable matter.  In order that this analysis
should take place, several circumstances must con-
cur.  It has been ascertained that matter, whether
vegetable or animal does not putrefy, if kept in a
running stream of water at a considerable  depth
from the surface.   If placed in a pond of stagnant
water, which barely  covers  the surface of the
ground, putrefaction  then ensues with  rapidity. 
 136        Remarks on Putrefaction.
 Here, moisture, one of the necessary attendants on
 putrefaction is afforded.  But even this is not suf.
 ficient, alone, to excite  the  putrefactive  process,
 since if vegetable or animal matter were placed un-
 der these circumstances, putrefaction could not
 take  place, if the temperature of the atmosphere
 were much reduced.  The materials employed in
 fermentation, would not be subjected to that in-
 testine motion, which indicates decomposition, if
 the necessary  degree  of heat  wrere  not afforded.
 And it is also evident, that if too large a propor-
 tion  of water be employed, fermentation will not
 ensue any more than  if all  the ingredients were
 combined in a dry state.  A heat between 60° and
 70° is said to be necessary to, keep up the process
 of fermentation.  It is certain that syrups tend to
 decomposition in warm weather unless they con-
 tain a great excess of sugar, so as nearly  to obvi-
| ate all moisture.  In the putrefation of vegetables,
 all their hydrogen is dissipated, while their oxy-
 gen  and carbon unite, forming carbonic acid,
 while a quantity of earthy matter with charcoal and
 iron remains.   Somewhat different is the result of
 the decomposition of animal bodies.  They con-
 tain one element, remarkably favourable to putre-
 faction, viz. azote or  nitrogen which,  with  the
 hydrogen forms ammonia;  carbonic acid  gas h
 also evolved, with carbonated hydrogen, phospho-
 rated and  sulphurated hydrogen.  To the latter,
 must be ascribed the peculiar foetor  attendant on
 the putrefaction of animal substances. 
           Remarks on Putrefaction.        137
  The same  results attend  the decomposition of
animal and vegetable matter, both in  the hands of
nature and art, and the same is effected by the na-
tural functions of animals, as we perceive in de-
composition in any  other way.  For  example, we
know the changes which ensue if animals or vege-
tables be exposed to a certain degree of heat and
moisture ; we perceive the very same effects pro-
duced by processes which are carried on in the la-
boratories of animals.  Their foeces exhibit the de-
composition of matter, the peculiar odour they pos-
sess gives a similar  factor, and in both instances,
we mark the  same chain of events.  However dif-
ferent the qualities of animal and vegetable matter
may be, it is certain, that the same causes will pro-
duce  similar  effects on both, and the same agents
will alike retard their decomposition.  It is there-
fore taken as granted, that heat unaided by  mois^
ture  or moisture  independent  of  heat,  cannot
effect the putrefaction of bodies.   And  we na-
turally  infer from such premises, that when both
these causes  exist putrefaction might be prevent-
ed, by such means  as obviate either  of them ; that
is,  if putrefaction has not already  commenced.
   The substances which  have been employed  to
prevent putrefaction,  have been called antiseptics.
Their mode of operation has never been fully un-
folded, nor do we with certainty, know  that the
rationale of their action can be easily  shown.  But
it becomes every one, who feels interested in natu-
ral phenomena, to  investigate with  care, and, if
possible, to trace effects to their causes, 
 133        Remarks on Putrefaction.
   I do not wish to enter into a long detail of all
 the antiseptics employed by art to obviate putrefac-
 tion ; this is foreign to my purpose.   I intend par-
 ticularly to  inquire into some things which have
 always been deemed of minor importance. Because
 I am well convinced that it is  not in the vast and
 stupendous objects of creation, that the grandeur
 of Nature is displayed,  but that it often shines
 more conspicuously in humbler spheres.
   I believe no  one has ever decided by actual in-
 vestigation, the philosophic use of muriate of soda
 in preventing  piitrefaction.    And  although  the
 employment of nitrate of potash  in  the  preserva-
 tion of  meat, is a practice of antiquity,  I do not
 know that any thing satisfactory, has ever been ad-
 duced on this subject.
   There is  not a good housewife in creation who
 does not know the great  importance of common
 salt in preserving meat in a sound state.   Unaid-
 ed by theory they confirm the correctness of their
 practice by  long experience. And there is scarce-
 ly an old woman to be found, who will not tell you
that nitre  gives a red colour to meat which it does
 not possess, if merely salted.
  We have already stated the  circumstances ne-
 cessary  to putrefaction.  As the equilibrium sub-
 sisting between the component parts of vegetable
 matter,  is supposed to be destroyed by an absorp-
 tion of oxygen  from the atmosphere,  so it has been
 concluded that the presence of oxygen* is neces-
  * It would appear however, that, oxygen which is concerned in
 this process (if any be concerned) is that existing in the meat either
as an elementary part3 or in fie moistur; of the meat. 
           Remarks on Putrefaction.        139
sary  to putrefaction.  This is proved, in some
measure, by the fact, that meat somewhat tainted,
is restored to a state of purity by means of char-
coal.
   Here it is natural to suppose, that by a play of af-
finities, carbonic acid  is formed and thus the pu-
trefactive  agency of oxygen destroyed.   We know
too, that in the economy of domestic  life, great
care is always taken to preserve meat tubs in such
a state, as to exclude air.   But neither the air nor
the charcoal are antiseptics.  The former is itself
a septic and the latter can do nothing more than ob-
viate the bad effects of putrefaction, after it has ta-
ken place. Very different, of course, must be the ac-
tion of muriate of soda; we must remember  in the
first place, that the ultimate object in view  in the
pickling of meat, is to  preserve its constituent
parts in that state of equilibrium, in which no che-
mical action can take place between them.   This
being the  case, it  would seem to  militate against
the supposition, that common salt acts chemically
on the ultimate particles of animal matters, to pre-
vent putrefaction.
  That some kind of chemical action is necesssaiy
cannot be, for a moment, disputed.  But if that
chemical action were of such a nature, as to ope-
rate on the ultimate particles of the matter, which it
is designed to preserve in a sound state, we see
no reason, why such action  might  not  effect the
destruction of that very equilibrium we  sougit to
preserve, and thus effect a new mode of existence
in the matter itself. 
 140       Remarks on Putrefaction.
   As I have determined to submit my conjectures
 to the scrutinizing test of experiment, I shall now
 offer a few more desultory propositions ; and
   1st.  Does not the action of muriate of soda in
 preserving meat, depend on the degree of cold ex-
 cited by its solution in water ? It is known to every
 one, that common salt dissolved in water, produ-
 ces a considerable degree of cold,  and it is also
 know, that the addition of nitrate of potash renders
 the degree of cold, much more intense.
   Now it has been already stated, and I think cor-
 rectly that putrefaction cannot go on without the
 aid of heat.  If this be  true, and if it be also true,
 that by the use of these saline bodies we create the
 very opposite of heat, viz. cold, who is there, that
 does not immediately conclude that the proposition
just stated, is correct ?  as cold cannot produce on
 animal and vegetable matter the effects of heat, so
 we infer, that it must act as a preventive of putre-
 faction, which is the effect of heat  and moisture
 combined.  How else  can we,  rationally, con-
 ceive it to act ? If it did possess a chemical opera-
 tion besides that of generating cold, we are not as-
 sured that it  would be necessary,  since we  are
 aware, that cold, alone, retards putrefaction.
   Besides we have said, that putrefaction does not
 take place when animal matter is inundated.  In
 the preservation of meat it is customary to keep it
 covered with the saline  solution.   Add to all this
 the fact, that meat tubs are  most  commonly kept
 in cellars, which are always cooler than any other
 part of a house.   That cold is extremely  influen- 
           Remarks on Putrefaction.        141
tial in preserving meat, if not the absolute cause, is
shown by the fact, that the removal of tubs into hot
situations, has actually been followed by the spoil-
ing of that part of the meat next the surface, which
perhaps was not quite  covered with  the saline so-
lution.   It is known also that animal bodies may
be preserved in spirit, but if a part of  the animal be
uncovered, that part will undergo the putrefactive
process in warm weather.
  2nd.  Does not the action of muriate of soda in
preserving grass and other vegetable matter from
putrefaction, depend on the production of cold ?
  I mean at this time, only to take into considera-
tion, a practice of farmers with respect to the pre-
servation of grass put into barns  in a wet state.
They know by experience, that common salt scat-
tered through it, prevents it from moulding, or in
chemical language from putrefaction.  It  is a fact
worthy of notice, that if clover fresh cut be put into
a barn or be stacked it will become so hot, as to ex-
cite, in  some cases, combution itself; and from this
cause, barns have actually been burnt.  Hence,  it
is customary to turn up the  clover  frequently, to
expose  it to the action of the air.   The  cause of
the great heat excited, must in great measure, de-
pendon pressure, by which caloric is extricated ; for
in stacks and also barns, the clover being  moist,  is
easily forced into close contact, and  it isobseived,
that while the outside  of a stack is nearly  dry, the
inside,  if examined, will be found  hot,  and in a
green state. It might be supposed, that in a slack
exposed to the sun, the external surface wouid be
                       T 
142        Remarks on Putrefaction.
cool, owing to evaporation; and it may be, that the
heat generated, is the  effect, not only of pressure,
but of partial  decomposition, and possibly of the
solidification of the  water contained in the  green
clover.  The latter is rendered probable by  the
fact, that the  heat is greatest where the grass lies
in contact with the earth.  But  to return from this
digression; Is it not  probable that the common
salt acts by absorbing moisture from the clover,
and thus generating  a certain degree of cold, sufii-
to prevent putrefaction ?  Where the salt is employ-
ed, the grass  is  preserved,  in  a sound state,  be-
comes dry much sooner and is more palatable to
horses.*  It is true,  that in turning up clover in
which salt has been  scattered,  heat  will be evolv-
ed, but this comes, chiefly ^ from that part of the
hay next the earth, and it is certain, that  the heat is
not so great, when salt has been employed.   If it
does not act as we have  supposed, we can imagine
no other way in which it can operate.   It certain-
ly does not afford any  principle of preservation,
which enters the composition of the clover and we
do think  it natural  to conclude,  that it operates
here as in the preservation of animal matter.
   3dly.  Does nitrate of potash give  a red color to
animal matter, or does its beneficial qualities  de-
pend on the power it possesses of generating cold,
or are both true ?


  • The clover taken from the salt marshes on the eastern shore of
Maryland does not require the use of salt for its preservation 
            Remarks on Putrefaction.        143
   Before this question is decided, we must observe
 that meat never posseses a more florid color, tian
 when fresh taken from the animal.   This is a fact,
 of which no one can be ignorant. It has been .sup-
 posed, that nitrate of'potash colors meat, by  im-
 parting to the latter its oxygen. But if this be the
 case, the nitric acid of the nitrate of potash must
 be decomposed,  and nitrogen must be  liberated,
 but  we do not know that this is ever the case.  In
 fact, it is more than probable, that if the nitric acid
 were decomposed, nitrate of potash, instead of be-
 ing useful, would prove an  actual cause of putre-
 faction, since by decomposition, it would afford a
 substance, highly favourable to this process, viz.
 nitrogen.  Thus by attempting to solve one diffi-
 culty,  another is created.   If  the  red  color de-
 pend on oxygenation, ought not the  same effect to
 take place, on exposing salted* meat to the action
 of oxygen ?  but it will  be  said,  that such an
 experiment could not be satisfactory, because it is
 probable that a definite quantity of  oxygen is re-
 quisite, and because immersion in oxygen might
 induce putrefaction.  But I answer, even though
putrefaction be induced, yet the red color should
appear previous to the  occurrence  of putrefaction,
if it be true, that oxygen is the cause of the red co-
lor.
  If the colour be more florid by  the addition of
nitre, which however I doubt, it must depend on

  * I mean here, by salted  meat, the  animal substance im-
pregnated with muriate of soda, only. 
144        Remarks on Putrefaction
some other cause than mere oxygenation.  It may
be the effect of mixture as in the production of co-
lors in other cases, the operation of which we do
not well understand.
  I am led to believe that nitrate of potash is use-
ful  in no other way, than by increasing the degree
of cold, produced by muriate of soda.  Because it
is evident, that if oxygen, itself, will not produce
a red color in salted meat, nitrate of potash cannot
produce the effect ascribed to it,  on the principle
of oxygenation.
  For the purpose of giving some confirmation to
the above remarks, the following experiments were
performed.
  1st. I  put a piece of fresh meat into a freezing
mixture, and  it  was  preserved  sweet  for several
weeks.
  2d. Having placed a piece of meat, impregnated
with a solution of muriate of soda, in a glass vessel;
I passed  in a quantity of oxygen gas.  This failed
entirely to alter the color of the meat, it was not
reddened in the least. 
A FEW REMARKS
UPON THE NATURE OF THE NERVOUS
               INFLUENCE.
 By Joel B. Sutherland, M. D.  Fellow of
   the Academy of Natural Sciences of Philadel-
   phia, Honorary Member ofihe Columbian Che-
   mical Society of Philadelphia. He.

     DURING the  existence of a considerable
 number of  years,  innumerable vague and  vi-
 sionary speculations, relative  to the nature of the
 nervous power, agitated the minds of Philosophers,
 famed for their  literary acquirements, in every
 branch of science.
   Some indulged themselves  with the thought,
 that it was a finely volatalized iEther, not cogniza-
 ble to the optic sense ; while others satiated, their
 philosophic curiosity with the idea, that it was de-
 rived solely from the vibrations of the- nervous
^cords, giving or abstracting motion from muscular
 system of pleasure.
/ 
146
A Few Remarks
   In this field of speculation, men whose  talents
 seemed to cast the rays of truth upon every other
 subjeet, proved altogether abortive.  Even  the
 immortal Newton, who in imagination, could mark
 the path in which the revolving earth should move
 A Franklin, the Prometheus of Columbia,  who
 with the bold hand of philosophy, stold fire from
 Heaven, a Hunter, so minutely acquainted with the
 mechanism of the animal machine, retired from the
 cares of this busy world, unacquainted with  the
 true nature of the nervous  power.  But although
 a Newton, a Franklin, and a Hunter, who shone so
 brilliantly among the departed sons of literature did
 not discover the exact nature of the vis nervea, still
 it does not follow, that a person of much meaner
 capacities, may  not develop  the  secret in our
 times.
   For in the days  of modernity, when science
 shines more resplendent than  heretofore; when
 the ingenuity of man is so great,  as to follow na-
 ture through her various meandrings, and expose
 to the admiration of the world, secrets which many
 of our forefathers, were convinced would lay con-
 cealed in the womb of time forever.  I say when
 such events as these have taken place, we must
 have a thousand different substances, and collate-
 ral circumstances to  aid us in our scientific en-
 quiries  with  which our predecessors  in science
 were unacquainted.   This  then is the  apology I
 shall offer for attempting to explain the true nature
 of nervous vis, a subject so long veiled in obscu-
ritv. 
 Upon the Nature of the Nervous Influence.  147
  When the learned D. Priestley made the world
acquainted with his discovery of nitr. us oxid, or
what  was  formerly called dephlogisticated ni-
trons gas,  he never once supposed, that at a fu-
ture day, this exhilerating gas, would be consider-
ed by any one, to be the great and only stimulus,
that should carry on the operation of the animal
system.  But nevertheless, I shall attempt to pre-
dicate this opinion, upon the firm basis of correct
reasoning.
  This globe  of which we  are inhabitants, is sur-
rounded by an invisible  fluid, commonly known
by  the name of atmospheric air,  whithout which
the life of man would  instantaneously cease, the
heart and arteries be silenced in death, and all the
beauties of creation would vanish into  non-exist-
ence.
   To  explain the manner in which air acts upon
the body, so as to become  highly important to the
vital operations of the system, will be the  object
of the  subsequent remarks.
   Atmospheric air is composed of about 22 parts
oxygen, 77 parts nitrogen  and some say 1 part of
carbonic acid in the hundred.  Now as soon as a
sufficient quantity of this mixture is inhaled by the
lungs, a general decomposition immediately com-
mences.  But with respect to this decomposition,
different opinions are tenaciously observed;  some
suppose that  the oxygen of the atmospheric air,
unites with the carbone of the venous blood, and
is finally eliminated from the system, in the form
of carbonic acid in a state  of mixture with the ni- 
148
A Few Remarks
trogen. But of what use would nitrogen be then?
they say to blunt the irritating effects of oxygen.
And why ? Not because nature intended her ope-
rations should be explained in such an imperfect
manner; but because nitrogen, according to their
theory appears to be of no other use. Thus much
for one of the  theories in high repute with some
chemical philosophers;  while  others advocate an
opinion, in a great measure directly opposed to
the one just mentioned.
   They say that the oxygen unites with  iron, or
something else in the venous blood, and thus pro-
duces a red colour, not negatively, as is the case in
the former theory, by decarbonization, but posi-
tively, by its union  with some of the  substances
in the blood.  But if this opinion  were correct I
would ask, from whence does the carbonic acid ori-
ginate, which is  observed in every expiration ?
   Does it originate from the carbonic acid, which
is said to be one of the ingredients in air ? No it
cannot.  For this is insufficient to correspond with
the quantity exhaled.
   Therefore such an opinion as that which suppo-
ses that oxygen acts positively in rendering  the
blood fit to pass from the veins  into the arteries :
according to my ideas upon the subject, is not only
conceived, but brought forth in error.
   From what has been said,  it must appear evident
that the great  aim of those philosophers has been
to establish a use for oxygen ;  while nitrogen, has
according to b th theories, been applied to no other
use, than to blunt the irritating effects of oxygen." 
 Upon the Nature of the Nervous Influence.  149
But if this was the intention of nature, I would ask
why did she form so large a quantity of nitrogen
to inflate the lungs, in conjunction with oxygen ?
why did she not make oxygen less stimulating and
more congenial to the pulmonary system ? If her
object was  what they  endeavour to  establish,
then nitrogen would  not be  required.  Certainly
Nature most commonly dresses her operations  in
the garb of simplicity.   And why should she here
make an exception to the rule ?  she has not. 'Tis
only the imperfection of a theory, that would make
it for her.
   I shall now endeavour to show the intention  of
Nature in  forming  our atmosphere as  has been
mentioned before.
   1st. That a portion of the oxygen might unite
with the carbon of the venous  system,  and thus
change venous, into  arterial blood ;  while the re-
maining portion of oxygen, would unite with the
nitrogen, and thus produce nitrous oxid, a stimu-
lus so congenial to the nervous system.
   But here some may remark, that there is more
nitrogen than is sufficient to form the whole into
nitrous oxid, or rather, that it is not in an exact
pioportion, viz. 63, 3 nitrogen,  to 36,  7 of oxy-
gen in a hundred.  Be it so.  Nevertheless a por-
tion of nitrous oxid may be formed, which would
(perhaps) be too stimulating  to the nerves, while
the other portion would reduce its activity. Thus
we  see nitrous oxid may be formed.   But here
some may ask, how  is nitrous oxid formed, when
nitrogen alone is saicj to be expired from the sys-
                       U 
150
A Few Remarks
tern ? I answer nitrogen alone, (or rather pure ni-
trogen) I believe never was expired from the lungs,
but an impure gaseous oxid of nitrogen which has
been mistaken for it.
   That this might be the case, no one will deny
when they recollect, that we have no positive test
for the presence of nitrogen.
   But I shall endeavour  to make it more evident.
If we abstract oxygen from an animal,  and feed
the system upon nitrogen, one of the ingredients in
our atmosphere, death will be the immediate  con-
sequence,  or if we reverse the practice and give
oxygen alone, death will finalize the scene.  Why
does such an occurrence as this take place ? Why
does the animal live with their union and not their
separation ? I answer.  Because  no nitrous  oxid
can  be formed, with one of those  ingredients.
Both are necessary for its production. Thus it ap-
pears very probable that nitrous oxid is necessary
to animal  existence.
   Having then rendered it very probable, that the
nitrous  oxid is necessary to life, I shall now at-
tempt to show that the nitrous oxid, and the  ner-
vous influence is precisely the same.
   When the gaseous oxid of nitrogen (or what is
now called nitrous oxid)  is mingled with atmos-
pheric air, and then received into the lungs, it ge-
nerates highly pleasurable sensations:  the effect it
produces on the animal system are eminently dis-
tinguished from every other chemical agent.   It
excites every fibre into action and rouses the fa-
culties of the mind, inducing a state of general ex- 
  Upon the Nature of the Nervous Influence.  151
hileration, an irresistible propensity to laughter, a
rapid flow of vivid ideas, an unusual vigour  and
fitness for muscular exertion, in some respect re-
spect resembling those attendant on the pleasantest
period of intoxication, without  any subsequent
languor, depression of nervous energy, or disagree-
able feeling.  Now if such an effect is produced by
nitrous oxid, viz. that of exerting every fibre  into
motion, and an increase of what we call nervous in-
fluence produces the same effect; may we not infer
that the nervous inflnence, and nitrous oxid are one
aud the same thing.
  But here some may ask, whether opium, wine,
and bark will not  increase the action in  the sys-
tem ?  yes it will.   But not in the same  manner.
When these medicines are taken into the system,
they lessen the excitement and of course  increase
the excitability  of every  muscular fibre.   When
this has taken place, the nervous power, although
no greater than before,  will act with more energy
and produce a greater effect.  This  then is  the
reason why opium, wine.  &c. increase the pulse.
Bnt here I may be asked, how I can determine
that opium does not  act like the nitrous oxid.  I
answer,  1st. Because there  is no diminution of
nervous energy, when we inhale the nitrous oxid.
And why is there no loss or diminution of nervous
energy ?  because the nitrous oxid is the  nervous
energy itself; therefore there can be no loss.
  2nd. Because the functions of the system  will
go on without opium &c; but will not without the
gasses from which nitrous oxid is formed. 
162           A Few Remarks
  I have now finished my remarks upon this sub-
ject, belteving from what has been said, that the
following inference may with great justness be
drawn, viz.   That the intention of nature in form-
ing our atmosphere of oxygen and nitrogen was,
that the gaseous oxid of nitrogen, might be formed,
so as to yield  nervous influence to the  system of
man, and thus carry on its vital operations. 
CHEMICAL  VIEW OF  SECRETION.
By Thomas  D. Mitchell M. D.  Fellow of
  the Academy of Natural  Sciences of Philadel-
  phia. Honorary member of the Columbian Che-
  mical Society of Philadelphia, He.

     THERE are  some subjects in physiology,
which from their apparent impossibility  of solu-
tion, have been classed among the hidden myste-
ries of nature.   Experiment and speculation have
followed each other,  but in vain; the difficulties
have not been removed and we  at last have been
compelled to take refuge in ignorance.
  The more immediate object of these remarks is
to consider the phenomena of  Secretion.  And
here as in many of the most important animal func-
tions, the aid of chemical science shall be invoked.
That science, by whose illuminating beams, the
sable gloom of nature has often been removed, and
the mysteries of creation exposed to the full blaze
of day. 
 154       CJiemical View of Secretion.
   Conducted by this torch, enter with me, for a
 few moments, the great laboratory of man,  and if
 the glimmerings of  the taper should grow fainter
 and fainter and at last expire, we can only console
 ourselves by reflecting, that in obscurity we found
 the subject and in darkness left it.
   I shall not attempt to fatigue the mind by offer-
 ing an epitome of the many vague conjectures on
 this subject.   Because the opinion I am about to
 support, might be deemed still more wild, and ren-
 der the whole irksome and disgusting.
   In the first place, I will state the position about
 to be supported, and then attempt its elucidation.
 The position is simply this.  That the difference
 in the  various secretions, depends chiefly on the
 difference in quantity of the oxygen contained in
 the blood, sent to the various glands.
   The position is founded in great measure on the
 difference between venous and arterial blood. The
 latter,  by chemical  analysis is found to contain
 more oxygen  than the former.   And perhaps it
 may contain even  more than has been supposed.
 With  regard  to this difference,  it  matters little
 whether we derive it'from the lungs or from the
 Thoracic Duct.  By the former the blood is said
 to receive a portion of oxygen, independent of that
 by which the oxide of carbon is elicited from the
venous blood.  By the latter viz. the thoracic duct,
 the blood is furnished with oxygen, because the
 substance, is no doubt, produced in  considerable
 quantity by decomposition of the elementary arti-
 cles containing it. Admit that the oxygen is sup- 
           Chemical View of Secretibn       15 5
plied from both sources, and then let us pursue the
fluentblood.
   In its course we shall endeavour to show, that
the quantity of alkaline matter in the secretions in-
creases as the quantity of oxygen diminishes,  or
that the characteristics of acid are gradually open-
ed.
   Thus for example, we  shall adduce the mam-
mary glands.  These are  the largest glands which
are near to the centre  of  circulation.   They are
supplied by vessels of considerable  size and of
course carry a considerable quantity of blood in as
high a state  of oxygenation as we find it in any
part of the system, except at the heart.
   If we examine the properties of the mammary
secretion, we find it to be sufficiently acid to red-
den the vegetable blues, and a given portion of it
contains less alkaline matter than is found in secre-
tions more remote from the  centre of circulation.
   It is unnecessary to take into consideration every
gland or surface of secretion in the human  body.
I shall therefore examine the secretions of a few
others which have always been considered as among
the most important.
   Let us for a moment consider the bile and urine,
two of the most extensive secretions.   Are not
these calculated to illustrate the truth of a remark
already made, viz. that alkalescence  increases in
the ratio of the distance of glands from the centre
of circulation ?  The  bile contains perhaps more
alkaline matter than any other secretion, and why?
I answer, by far the greater part of the blood from 
156        Chemical View of Secretion.
which the  secretion is produced, has  travelled a
most extensive and circuitous route before its ar-
rival at the liver.  The blood is in fact venous,
and  probably conveys no oxygen  to the  liver;
moreover, part of this  same blood had passed as
arterial blood through the substance of the pan-
creas, the secretion from which contains but a very
small portion of alkali.
  With lcspect to the urine, it  is found that acid
properties are evinced by the introduction of a ve-
getable blue.   This is explicable by the fact, that
the emulgent blood has not to travel a 20th part of
the4 distance allotted to the blood carried to the li-
ver by the  vena? portaerum. Let it be also remem-
bered that nearly gth of all the blood passes to the
kidneys.
  It may be said, that our mode of argument will
not explain the reason why the urine should pos-
sess  so much alkaline matter.  I am prepared to
meet this  objection.  Nearly every article which
chemical analysis has detected in the blood is found
in each of the secretions.  The quantity of each
article appears naturally, to be influenced by the
quantity of blood carried to each gland.   Now I
do not contend that the sensible difference in the
secretions  can be accounted for,  merely by the
variable portions of blood sent to different glands;
by no means.  I maintain that this difference de-
pends rather on the quality of the blood distributed
for the purpose of secretion.
   Now the blood in all situations, is found to con-
tain  certain substances,  but  I  do maintain, that 
           Chemical View of Secretion.       157
 •xygen is not found in venous as in arterial blood
 and that its quantity lessens  constantly from  the
 heart to  the  termination of the arterial system.
 Therefore that similar articles should exist in the
 different glands, is what we would naturally expect;
 and that a modification of these articles, so  as to
 render their combination in one instance bland, in
 another  bitter, is  to be attributed to the variable
 proportion of oxygen  conveyed to each gland by
 the circulation.
   The application of my  position to a general in-
 vestigation of glandular secretion, will no doabt be
 attended with difficulty.  Nor can  it be expected
 that we should be able to  obviate all obscurity, on
a subject, which has been considered over and over
again, without so much  as reflecting a single ray
 of light on its nature.
   The observations now made, if not in themselves
satisfactory, will, it is hoped, tend to a more gene-
ral attention to a subject so interesting to Physio-
logists.
X 
OBSERVATIONS
Upon the effects of various gases upon  the living
  Animal Body. By Edward Brux, of France.

    ALTHOUGH the subject of Respiration has
engaged the attention, and  exercised the genius
of very eminent physiologists, and although it can-
not be denied that the ingenious  experiments of
Haller,  Spallonzani,  Goodwyn  and others have
thrown a great deal of light upon this very impor-
tant function of the animal oconomy, yet notwith-
standing the discovery of many important facts, the
subject  remains involved in much obscurity, and
the experiments lately made in Europe satisfacto-
rily prove that much  remains yet to be ascertained
not only with respect to the chemical change which
takes place in the  blood in consequence of respi-
ration,  but more  especially with respect to the
agents and laws of the animal oconomy by which
this change is effected. 
Observations, He.            159
   Many  celebrated  physiologists by observing
 that blood exposed to oxygen gas, or even atmos-
 pheric air, changed gradually from a  deep purple
 to a bright scarlet on the surface exposed, and ac-
 quired the color, if not the properties of arterial
 blood, were induced to believe that the change
 effected in the lungs  was perfectly similar to that
 which they witnessed in their experiment, and that
 the function of respiration consisted merely in the
 mechanical  phenomena by  which  the  blood is
 brought in contact with atmospheric air, and in
 the change effected by the decomposition of this
 gas.  They considered the lungs as perfectly pas-
 sive, which is certainly true with respect to  the
 mechanical functions of respiration;*  for always in
 contact with the parietes of the thorax in a healthy
 state, they dilate and collapse with them in conse-
 quence of muscular action.  But they cannot be
 considered as chemical recipients, for from a series
 of experiments reported to the French Institute by
 Mr. Dupruytren on the subject  of respiration it
 appears that the contact of air is  not sufficient, and
 that it is not merely by the laws  of chemical affini-
 ty that the change in the blood from venous to ar-
 terial is effected.  But that it depends also upon a
 nervous influence which seems to be  as necessary
to the ( ue performance  of this function as it is to
that of secretion, nutrition, &c. it is true that Rich-
erand attributes to the lungs a vital energy.  But

  *  Contrary to the opinion of Dumas, Brumond  and others who
 supposed that the lungs are possessed of an innate power of mo-
 Urn. 
160            Observations,  He.
it is not till lately that the  cruel but very interest-
ing experiments made by several able physiologists
in Paris have at least rendered very plausible this
direct  influence of the brain npon the chemical
phenomena of respiration.  I say plausible for it
seems  that some of  their  experiments contradict
each other, and before this important point be fair-
ly ascertained, or looked upon as an axiom in phy-
siology,  many more experiments,  must be  per-
formed or those already made must be reinvesti-
gated,  and more  saticfactory conclusions drawn
from them.
  But if it be true that the function of respiration
is not yet completely understood, how much more
defective  is our knowledge of the deleterious pro-
perties of various gases  and  effluvia upon the
living  animal body, this is a subject which has not
yet been as  duly attended  to  as its  importance
seems to me to require,  and which offers to the
physiologist experimenter, and even to the practi-
tioner of medicine a very  extensive field for inter
esting and very useful investigation.
  The subject  of this dissertation being an en-
quiry into the proximate causes of asphyxia produ-
ced by the  Inhalation  of various gases, we will
begin  by  first investigating the effects of a  total
suppression of respiration, inquire what; obvious
changes  take  place which prove the  immediate
cause of death, and lastly we  will attempt to deter-
mine how far the inhalation of various gases seems
to induce asphyxia by  the deleterious properties
which  they possess, and how far we are to attri- 
Observations, He.            161
bute the various symptoms which follows  their
inhalation to their negative properties or incapabi-
lity of oxygenising the blood.
  1st. Of the changes which the blood undergoes
in respiration, that which  is returned to the heart
by the venae cavae, &c. is afterwards sent into the
pulmonary arteries by the contraction of the right
ventricle, is heavy and  of a deep purple colour.
According to Richerand  its temperature is only
30° of Reaumur's thermometer,  and if suffered to
remain  still, it coagulates slowly and  separates a
large portion of serum.   That which  is  brought
back to the heart by the pulmonary vein, and which
is conveyed into every part of the body by means
of the arteries, is on the contrary of a red Vermil-
lion colour, frothy, lighter and two degrees warm-
er;  it is also more easily coagulable and separates
a smaller proportion of serum.
  All the changes in the colour and properties of
the blood which are so easily perceptible and which
certainly depend  upon  the modifications  arising
from having been in contact with atmospheric air,
have given rise to many  interesting experiments
and ingenious speculations.  It is not indeed sur-
prising that a subject of so great importance should
have attracted the attention of physiologists, who
in  this as well as many other  obscure points of
this  science have too ,often relinquished truth in
search  of proper arguments to defend and support
a favourite hypothesis.
   Some have supposed that the change depended
merely upon the absorption of oxygen, whilst it has 
  162           Observations, He.
  been attributed by others to the absorption of this
  gas, and the emission of carbon.   According to
  Richerand the blood in changing from venous into
  arterial, absorbes a portion of oxygen and caloric,
  which combining with hydrogen and  carbon  in
  every part of the body form water and an oxide of
  carbon; the former dilutes  the venous blood, ren-
  ders it more fluid than arterial, and when  in the
 lungs exhales dissolved by the air, forming the pul-
 monary transpiration  or exhalation;  whilst the
 oxide of carbon by combining with a fresh supply
 of oxygen when under the influence of respiration
 constitutes  the carbonic acid gas found combined
 with the air expired.
   This theory is ingenious and seems to be the.
 most plausible of all the various speculations upon
 this subject.  Many physiologists have, however,
 even lately attempted  to refute it.   Dr. Bostock
 supposed the aqueous vapour  emitted from the
 lungs to consist of the  water poured into the blood
 ready formed by the thoracic duct,  and Messrs.
 Allen and Peppy concluded from a  series of ex-
 periments that no water is formed in  the blood by
 the combination of hydrogen and oxygen, whilst
 Mr. Abernethy maintained that the carbonic acid
 is not the product of respiration, but simply ex-
 haled from the  pulmonary vessels.   It would be
 both  useless and  uninteresting to spend much
 time  in investigating  the various opinions enter-
 tained by different writers upon this subject;  and
whatever may be the precise change which takes
place in the blood when circulating  through the 
Observations, He.            163
capillary system of the lungs the fact is certain that
a change takes place, by which the blood is as it
were, revivified. That such a change  is necessary
to the due performance of all the different functions
of life, experience has  given us too many melan-
choly proofs.   Indeed  as  we shall see hereafter,
death from submertion  strangulation  and suffoca-
tion is always the consequence of a total suppres-
sion of the chemical phenomena of respiration, or
in other words, of an interuption of this change in
the properties of the  blood.
   This is not, however,  an universal opinion among
physiologists; very far from it: this point has been
the subject of much controversy and debate,  and
if we look over the  works of different writers, we
will find that they have each of them started, and
attempted to establish an hypothesis  of their own.
Haller  and other able  physiologists  supposed the
proximate  cause of asphixia to depend  upon a
collapsed state of the lungs which occasioned death
by mechanically obstructing the circulation of the
blood in this organ, and of course, through the
other parts of the body; it was by this explanation
 (perhaps modified  by  succeeding  writers)  that
 physiologists accounted for the death  succeeding a
 preternaturally protrated  expiration, until the ce-
 lebrated Goodwin by a sett of very ingenious ex-
 periments, proved their theory to be erroneous, and
 the interruption of the mechanical functions of res-
 piration, to be only indirectly the cause of death.
 It is to the cessation of the  chemical  phenomena
 which must inevitably follow  a  privation of the 
  164           Observations, He.
 agent which supports them, that this eminent phy-
 siologist attributed the cessation of the contractions
 of the heart; according to his opinion, the left ven-
 tricle not finding in the unoxygenised blood a suf-
 ficient stimulus  to  excite it to action, ceases to
 perform its important function of transmitting the
 vital fluid to every part of the body, and life then
 ceases because the circulation  is stoped.   Good-
 wyn's  explanation differs then from that  of his
 predecessors in this point only, that he refers to
 the  heart exclusively what they attributed to the
 state of the lungs.   But although he made a step
 towards the  truth, he  did not,  however, give an
 explanation which could stand the test of succeed-
 ing  investigation,  and the celebrated Bichat  proved
 by observations and by many direct experiments
 made upon living animals that the circulation is
 not  immediately stoped and that the  stimulus  of
 nervous blood may produce upon the internal sur-
 face of the left ventreil a sufficient degree of excite-
 ment to form it to contract, if not  altogether with
 as much force  at least in a very sensible manner.
 According to this  very  ingenious physiologist, life
 does not cease  because  the blood is not sent  by the
 heart to every part of the body but because this or-
 gan  transmits to them a fluid not only incapable of
 exciting them to action; but even possessed of de-
 leterious properties, " it is," says he,  " by  circu-
 lating in the  coronary arteries, and  by penetrating
 the texture and debilitating each fibre of the heart
 individually,  that the venous blood acts in inducing
ft cessation of  the contractions of this organ, and 
Observations,  He.            165
not merely by coming in contact with its internal
surface.  But it is not upon the heart alone that it
exerts its deleterious influence; it acts upon every
part of the  body and destroys the function of the
brain, of the voluntary muscles, of the membranes
and in a word, of all the different organs through
which  it circulates,  exactly  in the same manner
that it inflames the heart.
   This explanation of the cessation of life is at least
very  ingenious,  and seems to be very  plausible.
But supposing it to be true, a very important ques-
tion remains yet to be solved.   How does venous
blood act upon the  nerves or fibres in inducing
asphyxia ? is it possessed of deleterious properties
from  being supersaturated with hydrogen and car-
bon ?  or is it indirectly that it occasions death by
being deprived  of the  principle emissary to,the
action of the different organs ? * but although the
retention of carbon is one of the causes of death,
venous blood cannot, I think,  with  propriety be
said to possess any deleterious properties from its
being discharged with  this principle for it is not
on account of the quantity of carbon which it al-
ready  contains that it proves  injurious; But on
account of its  being  deprived of the property of
abstractingthisdeleteriousprinciplefrom every part
of the body; on the other hand, the absorption of

  * We might cite the authorities of Eicherand and Bichat in sup-
port of the opioion entertained by some physiologists respecting the
positive noxious properties of venous blood. Richerand says -'per-
haps also the venous blood accumulated in every structure, affect';
the different organs with itp blunting and cemortiferous qnalitie?
                        Y 
166            Observations,  He.
oxygen cannot, I think, be, as some have supposed
entirely subservient  to  the  evolution  of carbon.
Whether this  gas is the principle of excitability or
not? a question which many years  ago was  the
subject of much  controversy  among hypothetical
physiologists,  I will leave to more able and specu-
lative physiologists to decide, although I must con-
fess, that irom my ideas  of the true meaning of the
word irritability or excitability, I should be indu-
ced to think that it was a property or a quality of
matter as Dr.  Rush expresses himself, and  not a
substance.
   But I think, that besides  serving the important
purpose of decarbonising the blood, the absorp-
tion  of vital air, no doubt imparts to this fluid other
properties which render it capable of exciting into
action the heart and other organs.
   Thus it appears that when the respiration is stop-
ped by any mechanical means, the unoxygenised
state of the blood, and the retention of carbon which
must inevitably follow the interruption of oxygen
to the lungs, are the proximate causes of the ces-
sation of life.   Death from submersion or stran-
gulation of life must then be  accounted for upon
this  principle.  Since from the experiments of
Kite, Coleman, Goodwyn and others, it is very
satisfactorily proved that the cessation of life from
the above  causes depends upon the interruption of
the mechanical phenomena of respiration.
   It is also  in this way that the inspiration of va-
rious gases leads to induce asphyxia.  It was first
ascertained  by Mr.  Lavoisier, and  Mr. Seguin 
Observations, He.            167
that hydrogen or nitrogen when received into the
lungs in a stste of purity, are altogether passive and
destroy life only by preventing the access of oxygen.
The truth of this interesting fact has since been
confirmed by the experiments of Mr. Davy and
ether chemists; carbonic acid gas is also supposed
by  Richerand to  act in the same way in  inducing
asphyxia, and a member of this society has lately
attempted to account  for the  negative properties
of this  gas,  diough containing a certain  quan-
tity of oxygen, by observing, that the matter which
is to be thrown off from the lungs, being  similar
to that which forms the base of carbonic acid gas,
the oxygen will not quit the latter to join the for-
mer;  from this he concludes that no air can be re-
spired for any length of time, which does not con-
tain a portion of oxygen united to something dif-
ferent from  the  matter to  be evolved from  the
lungs; although his conclusion is correct  as far as
it relates to carbonic acid gas, it is not strictly true
taken in a more general point of view, and  suppo-
sing his ideas with respect to the manner in which
the inspiration of this gas induces asphyxia to be
perfectly just, his sentence, by a  little alteration
may be rendered more generally and  more strictly
correct.   He ought to have said, no air can be res-
pired for any length  ot time  with safety,  which
does not  contain a portion  of oxygen united to
something for which it has  less affinity  than for
the matter to be evolved from  the lungs"  for on
the other hand oxygen gas may be, and is in reality
contained with aqueous vapour,  which matter rs 
 168           Observations, He.
 certainly evolved from the lungs, and yet we do
 not find that by this combination it  is deprived of
 the property of oxygenising the blood even  per-
 haps in the smallest degree, and on the other we
 know that oxygen though not contained with car-
 bon in the form of carbonic acid gas may notwith-
 standing be rendered unfit for respiration by being
 united to something  for which  it has a srronger
 affinity than for carbon, or the matter to be evolved
 from the lungs.
   But although we might upon this principle satis-
 factorily account  for death taking place,  when an
 animal is confined in an atmosphere of carbonic
 acid gas,  yet from various circumstances,  I feel
 confident in my own mind that succeeding experi-
 ments will prove  the positive deleterious proper-
 ties  of this  gas  when  received  into the lungs.
 The impossibility of respiring it in a state of pu-
 rity, was  proved by   the  experiments  of the
 unfortunate   Pilatre de Rosier,  and  those  of
 Mr. Davy.   This celebrated chemist tells us that
 when he attempted to breathe a mixture of two
 parts of common  air and three of carbonic acid, h
produced a burning cessation at the top of the uva-
 la, and stimulated the Epiglotis  so as to close it
 spasmodically upon the glotis, and thus in repeated
 trials to prevent him from taking a single particle
 of it into his lungs even by the most powerful vo-
luntary efforts.  This want of success  however,
only served to increase,  instead of diminishing his
intrepidity; he mixed three quarts of carbonic acid
 with seven of common air, and finding that it wa« 
Observations, He.
169
respirable, he  breathed it near a minute.   At the
time, says he, it produceda light degree of giddiness
and an indication to sleep.  These effects however,
very rapidly disappeared.   Dr. Botock, it  seems
attributed also  to carbonic acid noxious properties,
for in speaking of the effects of azote when taken
into  the lungs, he says, it produced a sense of suf-
focation  more speedily than hydrogen, but it ap-
pears that the gas employed in the experiment con-
tained a quantity of carbonic acid to which we may
with great probability ascribe its noxious proper-
ties;  carbonic  acid, says Mr. Davy, possesses no
action on arterial blood,  hence perhaps its  slight
effects when breathed mingled with  large quanti-
ties of common air; its effects are very marked
upon venous blood !  if it were thrown forcibly in-
to the lungs of animals,  the momentary applica-
tion  of it to.the pulmonary venous blood would
probably destroy life; many other authorities might
be quoted in support of the opinion entertained by
many physiologists respecting the noxious  pro-
perties of this gas; they seem all to agree in attri-
buting to it when sufficiently diluted with common
air a certain sedative property, in  consequence of
which it destroys life apparently by rendering the
muscular fibre irritable, without  producing any
previons excitement.  The effects of hydrocarbo-
nate  gas seem to be  very much  alike those of
carbonic acid  when  taken into the lungs, though
from the observations of Mr. Watts and the expe-
riments of Dr. Beddoes, it seems probable that the
former is perhaps more highly deleterious.  Its ef- 
  170           Observations, He.
 feet are thus described by  Dr. Bostock;  " if the
 carbonated hydrogen gas," says he, " be inspired
 in an undiluted state, it is followed by instant death,
 and when employed in small quantity only, mixed
 with atmospheric air as  with oxigen, if it  be used
 for any length of time, it induces vertigo dimness
 of sight, convulsions, loss of sensation; and in short
 every symptom of approaching dissolution.  "The
 noxious influence  of this gas," he adds, "I con-
 ceive with more propriety referable to its action upon
 which  it produces directly sedative  effects;  we
 might to this short analysis of the effects of hydro-
 carbonated gas, add a quotation of the interesting
 and beautiful description by Mr Davy of the ter-
 rible effects of this gas upon himself.   But as it is
 too  long I will content myself in quoting a part
 of hislast paragraph in which he says, " I have been
 minute in the account of this experiment because
 it proves, that hydrocarbonate acts as a sedative, i.e
 that it produces diminution of vital action, and de-
 bility, without previously exciting."
   From these interesting accounts of the effects of
 carbonic acid and hydrocarbonate gas, to which, if
 necessary, many more might be added; we may
 safely conclude,  that, if some gasses seem to pos-
 sess only negative properties when received into
 the lungs in a state of purity, and  to  induce as-
 phyxia only by preventing the  access of oxygen,
 there are others  among  the  respirable gasses or
those which may either in a diluted  or pure  state
be received into  the lungs, which possess positive
and highly deleterious properties,  and which al- 
Observations, He.            171
though they might produce, like the former death,
their incapability of oxygenising and decarbonising
the blood,  nevertheless occasion such  traces of
symptoms as cannot be refered  to  a state of the
blood, and leave in the mind of a faithful observer
no room to doubt of their noxious qualities.   But
it may be asked, how do such gases when inspired
act in destroying life?  this is  a question of the
greatest importance either in a practical or physio-
logical point of view, and which requires the per-
formance of many  experiments and the careful in-
vestigation of very ingenious and perhaps specula-
tive physiologists before it be fully and satisfacto-
rily explained.   But little, I believe, can,be said
upon this important subject at present; what  I
shall say upon it may be comprised in a few obser-
vations among the various gases possessed of dele-
terious properties, some seem to act by their cor-
rosive nature, and to create inflammation and gan-
grene in the substance of the  lungs themselves:
among these may be ranked various concentrated
mineral acids in the state of vapour, an atmosphere
loaded with various metallic substances of a highly
stimulating nature such as arsenic, corrosive sub-
limate Sec. in a very subtile powder; among these
are also placed by Richerand the exhalations of pri-
sons or burial-places; in asphyxia induced by these
effluvia, says this great physiologist, the lungs are
often covered with black and gangreous spots, and
death seems to be the effect of a poison, so much
the more active as its parts being extremely divided
and reduced t© a gaseous state are more penetra- 
172           Observations, He.
 ting and affect the nervous and sensible surface oj
 the pulmonary organ throughout its whole extent.
 Many other gases however do not leave after death
 any marks of a loss of organisation in those parts
 which we know to have been the medium through
 which the injury had been  sustained and as we
 have already attempted to prove that all gases are
 not deleterious merely by a relative action, as some
 have supposed, we must explain the phenomena of
 asphyxia m these cases upon other principles. Do
 not the interesting experiments of Mr. Davy upon
 nitrous oxide throw some light upon this  impor-
 tant subject? and is it not probable that this  gas,
 like oxygen is absorbed by the blood,  and being
 sent by the heart to the brain and other organs de-
 stroys life as Mr.  Davy expresses himself by pro-
 ducing the highest possible excitement.
   I cannot however suppose carbonic acid and ma-
 ny other gases to be absorbed, and their effects
 may be I think soon satisfactorily accounted for in
 another way; the experiments of Mr. Dupreytren
 Mr. Legallois and many other able physiologists in
 Paris which tend to prove that instant death is al-
 ways the consequence of a division of those bran-
 ches of the eigth pair which supply tlie pulmonary
 organs, and consequently that a nervous influence
is necessary to the du^t performance of the impor-
 tant function of respiration, seem to us to he very
interesting and well  worthy of the  attention and
 carefulinvestigationofphysiologistswhoarecapable
of handling  such a difficult subject; do not those
experiments tend to  throw some light  upon the 
               Observations, He.            173
 deleterious effects of gasses ? and  since the diffe-
 rent organs, but  more  especially  the stomach is
 susceptible  of being excited by  so many  various
 stimuli, and of affecting by sympathy the brain and
 indeed the whole system, why should not the lungs
 possessed also of a nervous influence be equally
 susceptible of being variously excited by  the sti-
 mulus of various gases, and of sympathising with
the other organs?  may not carbonic acid and  hy-
 drocarbonate gases, to  which we  have seen Mr.
Davy and Dr.  Bostock  (influenced  only  by  the
 symptoms which they witnessed,) ascribe directly
 sedative properties, may  not these  gases, I say,
 act upon the pulmonary system exactly in the same
 way that a large dose of opium acts upon the ali-
 mentary canal? But let us not seek to  penetrate
farther than experience can guide us; and although
 the advice of our experienced professor Dr. Rush
 of speculating upon physiological subjects may be
the source of the  most important discoveries, yet
I believe the following observation of Dr. Bostock
to be founded upon the truth,   " Physiologists,"
says he, " have, in general, been more inclined to
form hypothesis than to execute experiments, and
it has necessarily ensued from this unfortunate pro-
pensity, that their science has advanced more slow-
ly than perhaps any other  department of  natural
philosophy."
2} 
ANALYSIS
                     OF

 PROFESSOR COXE'S ESSAY ON COM-
    BUSTION AND ACIDIFICATION.


J3y Thomas  D. Mitchell M.  D.  Fellow of
  the Academy of Natural Sciences of Philadel-
  phia. Honorary member of the Columbian Che-
  mical Society of Philadelphia, He.

    I have long thought and still believe that mat-
ter was at  one period quiescent, and that its sud-
den transformation into forms  innumerable, was
the effect  of  a grand and general  combustion.
Perhaps the electric fluid  which I consider as one
of the pristine parts  of creation, was  the grand
agent in  effecting this process.   Would  it not
seem that combustion had preceeded the various
products  of our  globe, when we  recollect what
are the effects  of combustion in our own  hands.
It produces an acid, an oxyde or water.  In all 
           Analysis of an Essay, He.        175
 creation there is not perhaps an atom which does.
 not belong to one of these classes.
   Metals may  be  called simple, but I rather be-
 lieve them to be compounds, and that they are ne-
 ver found free from oxidation in some degree.
 View then this grand process converting all mat-
 ter into forms which must be classed either among
 acids, oxydes, or water. The combinations of sa-
 line  matters, the vast and boundless current mean-
 dering to the world's extremes, are placed in one
 view before us, and thus in earlier days as at pre-
 sent, we behold combustion, as the grand agent of
 decomposition and  recomposition.  This view is
 simple, but perhaps not the less correct.
   Every theory therefore  of the  phenomena of
 combustion that discords  with the  original and
 universal process must be founded in error.
   In considering this essay, I shall begin by ana-
 lysing the first  objection to the Lavoiserian sys-
 tem  of chemistry.   The author adduces from Dr.
 Thomson the following experiment, viz.  " If 8
 parts by weight of copper filings, mixed with 3
parts of the flowers of sulphur, be put into a glass
 receiver, and placed upon burning coals, the mix-
 ture first melts,  then a kind of explosion  takes
 place;  it becomes  red hot; aud when taken from
 the  fire, continues to glow for some time  like a
 live  coal.   If we now examine  it we find it con-
 verted into sulphuret of copper.  This experiment
 succeeds equally well however fine and dry the sul-
 phur and copper be; and whatever air be present in
the gliss vessel, w hether common air, oxygen gas, 
176          Analysis of an Essay
hydrogen or azotic air."  Now what is to be pro-
ved by this experiment ? Why, that combustion
may go on without oxygen; and does it prove this?
far, very  far from it.   To say the least of this ex-
periment, it is certainly improbable.   I will grant
for a moment that  something  like  combustion
might go on even in contact with azotic gas; but
will  any man of plain common sense, credit the
assertion, that azotic gas, is as favourable to com-
bustion as  oxygen  gas? The flowers  of sulphur
as every  man knows,  contain a portion  of acid,
and it follows that if combustion did ensue in azo-
tic gas,  it  was dependant on the acid existing in
the flowers of sulphur.  But  even admitting that
we were  unable to explain this supposed anomale;
is the whole system to be blasted by  one solitary
objection?  why does the author of the essay pass
over this experiment and attempt neither its proof
nor disproof?  he was either,  not in quest of the
truth, or felt his inability to solve  this apparent
difficulty.
   I must beg leave to correct the professor before
I go further,  with regard to Mr. Lavoisier.  He
misunderstands that celebrated and  illustrious au-
thor.   Speaking of light and flame,  he says, " La-
voisier supposed them  to constitute  a part of oxy-
gen in its gaseous  state, and that they separated
from it, when it became fixed in the combustible."
Now, Mr. Lavoisier did not mean that all the light
and heat  separated; on  the contrary,  he has proved
by experiment, of which any man may  satisfy him- 
on Combustion,  He.
177
self, by reading the " Elements," that a part only
of them was separated.
  But I come to another point,  and here let the
error first corrected, be kept in view.   " The ca-
loric  of  atmospheric oxygen  escapes," says the
professor, " when it loses its gaseous form or be-
comes united to the burning body,  as  caloric es-
capes from the latent to a free state, when water in
the state of vapour condenses to the fluid form.
" But how," continues he, " can we reconcile this
with the  attendant phenomena of the combustion
of gun powder, in which numerous fluids are pro-
duced suddenly from a state of previous solidity."
   How  weak, how  futile is this argument!  will
men ever search the truth in scientific  inquiry, or
are they  always to grovel  in  error? Before consi-
dering the phenomena cf  the combustion of gun-
powder,  I will oppose one question to the argu-
ment made use of.   The professor thinks  that the
antiphlogistic system is imperfect, because it can-
not account for the fact that a solid body should
suddenly be converted into a large volume of elas-
tic matter.  Why then, I ask, is one drop of water,
capable  of being converted into a form more fluid
and with its bulk increased many hundred times?
 true, it may be said, we do it by the force  of calo-
 ric.   And pray, have  we not the same force  in
 gun-powder? or rather let me ask; did Lavoisier
 toil in experimental inquiry to prove this point, by
 irresistible evidence twenty years ago, and has it
 not yet  reached the ear of the professor?  it can
 scarcely be so. 
 178          Analysis of an Essay
   I wish not to force the judgement of any man,
 but to set the truth before his eyes  In page 158 of
 Lavoisier on Nitric A cid we read thus; " We have
 before seen that in the state of oxygen gas, it con-
 tained at least 66, 66667, of caloric; therefore  it
 follows that in combining with azot to form nitric
 acid, it only loses 7,94502." This is the result of
 experimental  research, and  proves that a given
 quantity of oxygen  gas containing 66 parts of ca-
 loric, lost only 7, when it combined with nitrogen
 to form nitric  acid.   " This enormous quantity of
 caloric," says the great Lavoisier, " retained by
 oxygen in its combination into nitric acid, explains
 the cause of the great  disengagement  of  caloric
 during  deflagrations of nitre,  or more strictly
 speaking upon all occasions of the  decomposition
 of nitric  acid.
   " But," says the professor, " whence can arise
 the caloric so suddenly reqnired to retain them in
 a  gaseous form? It will scarcely he said to come
 from the  solid materials since this would mili-
tate against his own opinion."  No man  could
have understood the writings of Lavoisier, while
 writing in such a style as this, since it is evident
that the subject has been fully explained.
  With  regard to the Professor's remarks on Dr.
Thomson's theory  of combustion, I would only
say as I have done in another place, that  it is but
a modification of Lavoisier's theory, and perhaps
less correct than the latter.  I  have also said some-
thing of the inflammable principle, so called, but 1
have still more to say*   Let the champions  of this 
on Combustion, He.            179
principle come forth with all the fury  of galvanic
agency, and still, hydrogen, as this principle, will
do little more than float aloft in the atmosphere of
fancy.   There may  it stay, till driven  by  some
more adverse wind, it shall be dashed at last on the
rocks of perdition.
  Where was philosophy  and reason,  when in-
flammability, or the power of burning  was con-
signed to one solitary agent? I challenge the whole
host of opponents  to the antiphlogistic  system
to  adduce  one  single  instance in  all nature,
in  which  any  body  separately  possesses an
absolute principle  or quality.  When we speak
of the properties of bodies, as taste, smell, &c. we
do not mean that any of them possesses a positive
quality.  They are merely sensations or effects re-
sulting from the actions of those bodies  on our or-
gans of taste, smell  &c. Inflammation, like odors,
is the result of relative circumstances and not the
product of a single agent.
  The Professor says, " when we find  a peculiar
principle uniformly enter into  the composition of
one certain class of bodies,  it can  scarcely be
deemed visionary to attribute to its presence, some
Common property  of that class.  This common
property of that class, then, is combustibility; that
common principle is hydrogen."  This however,
is by no means such reasoning as can  be admitted,
because the premises of the author are not granted.
He has not proved, the existence of hydrogen as a
common principle in combustibles, and there  is
good ground for believing that its existence is often 
  180         Analysis of an Essay
  merely adventitious.    Therefore  the Professor
  should recollect, to take nothing as granted, which
  has not been proved.
    The Professor is of opinion that the reduction
 of metals from their oxydes by hydrogen, is effected
 by double affinity, and in a note he remarks,  that
 such conjecture is in conformity to one of the laws
 of affinity, laid down by Mr. Berthollet.
    Now, I would beg leave to differ from the Pro-
 fessor on this point.   In  the  first place, I deny
 that it is a case of double affinity and in the  second
 place, whether simple or compond, Mr. Berthol-
 let's laws have nothing  to do with it. The particu-
 lar law alluded to, does not operate in every case
 of chemical  action, but  is restricted in  agen-
 cy.  By it  we  learn,  that  chemical action may
 be and often is influenced by the quantities of mat-
 ter brought within the sphere  of action.  But
 when we reduce metals  by hydrogen, we  do not
 force the action by increase of mass, by no means.
 The action is plain and simple and no man  has
 ever attempted to make any demonstrations capa-
 ble of disproving that simplicity of action.
   " It must be remembered," says the Professor,
 " that all the bodies capable  of reducing metallic
 oxydes possess this principle, hydrogen."   Now
 I deny this with equal force; all such bodies  do not
 possess hydrogen; nay further it is conjecture and
 delusive experiment that has found it in many bo-
 dies.   "The  reduction of metals  by charcoal,"
 says our author, " is supposed  to  be effected  by
the charcoal uniting to the oxygen of the oxyd, and 
              on Combustion,  He.            181
 fly;ng off as carbonic acid gas, leaving the metal
 pure; but " says he"  what becomes of the oxygen
 of the charcoal? I answer; prove first, that the hy-
 drogen which is adventitious, is essential to me-
 tallic reduction.  I say, it is not.   The Professor
 supposes  " that the hydrogen goes to  revive the
 metal, part of it at least,  while the  remainder ad-
 heres to the charcoal to render the base capable of
 acidification."  Why one would suppose that the
 charcoal in these cases was nothing but a mass of
 condensed hydrogen,
    I would beg leave here to state, that in my opi-
 nion, the existence of hydrogen in  charcoal has
 been completely  disproved.   In an  experiment
 made by *Dr. Woodhouse with oxyde of iron and
 charcoal in which these substances were  exposed
 to a  red heat, the metal was not revived, nQr did
 hydrogen appear in any shape; as was proved by-
 Mr.  Cruikshank. Now had the charcoal have con-
 tained hydrogen, this  would have been evolved in
 form of gas.   But no product of this kind was ob-
 tained.  The Phlogistians, a priori, would tell us
 that the hydrogen would combine with the calx in
 order to reduce it,  but no reduction in this case
 was effected.  Then I ask where is the hydrogen
 of charcoal?
  - The Professor says " analogy supports us in the
 belief of  an inflammable principle.   There is

   • The Doctor once thought this experiment an objection to the
 Lavoiserian system. But as soon as Mr Cruikshank investigated the
 subject and published the  results ofhis inquiries, the Doctor recant-
ed, and admitted the justness of subsequent discoveries.
                       A a 
182          Analysis of an Essay
" says he" a common principle of repulsion in calo-
ric, of vision in light and of sound in air."  This
is truly strange philosophy; I aver there is no prin-
ciple of repulsion in caloric, of vision in light, or
of sound in air.  To grant the existence of a re-
pelling  power  in particles of caloric,  is to gnmt
spontaneous motion to matter, is to  say that mat-
ter  moves itself.   To admit a principle of vision
in light, is to depreciate the organs of seeing, as
useless.  Vision means the power or act of seeing,
and does light possess this property?  certainly not.
Again of sound;  how can a principle of sound be
ascribed to air, since like light and caloric, it is only
capable of being acted on? So with the principle
of acidity; there  is in fact  no such thing, in any
agent whatever, for acidity always results from re-
lative causes.
  " The products of combustion will  not burn,"
says our author, " and why? They have either lost
this inflammable principle, or it is so modified by
the process of combustion as to be no longer gover-
ed by the same laws of affinity that previously con-
trolled it." Now water is a product of combustion;
such products according to the professor, will not
burn, because they have lost their hydrogen;  there-
fore in conformity to the strictest rules of logic, we
say, water does not contain hydrogen !!! and why?
because in combustion, the inflammable hydrogen
is lost !  Into what errors would such conclusions
leads us? they are dangerous and miibt be avoided.
   The  Professor tells us " that  although oxygen
increases the absolute  weight of  metals in a state 
on Combustion, He.           183
of oxidation, yet it lessens their specific gravity;"
he therefore infers it be a principle of levity. Why
not, I ask; call it a  principle of weight, if the fond-
ness of a principle in every thing must be gratified.
If a principle at all, it is equally so with regard to
weight as levity.
  The professor  attempts to reconcile the con-
tending theories  by introducing the comparative
weight of hydrogen and oxygen,  and endeavoring
to make it probable that a small portion of hydro-
gen actually escapes during the combination of oxy-
gen with the metal. Hence he infers that as hydro-
gen escapes, it does so as a principle of inflamma-
bility.   But  no man  will ever  accede to sucji
conjectures, when supported neither by  fact nor
probability.
  The difficulty started by the professor relative to
the production of hydrogen gas from  sulphuric
acid, iron and water, is merely imaginary.  No de-
monstrative evidence can be adduced against the
simple mode of explaining this process, none has
been offered.   Then why should we reject sim-
plicity, merely to gratify vain speculation? There
is as little reason why the action  should  be com-
pound, in this case, as in the production of hydro-
gen gas from the decomposition of water in a gun
barrel.
  " The most powerfully concentrated solar rays,"
says our author " produce no flame in incombus-
tibles.   They fuse and volatilize, the hardest in-
combustible, 'tis true, but no flame follows;  yet
caloric and light  are both present in the concen- 
184          Analysis of an Essay
trated rays, as well as probably in the body expo-
sed  to them; but the defect of this inflammable
principle (meaning hydrogen) as a constituent of
of the body, precludes effectually the possibility of
flame."  Here let us pause a moment and inquire
what agents  are necessary to effect a combustible
process.    Oxygen gas and a combustible at least,
are indispensable, yet the author in the above lines
has  lost sight of oxygen  gas altogether.   This
agent is the efficient cause of the incapacity of in-
combustible  to burn.  What is combustion,  but
the  union  of oxygen with a base;  and if this be
true, what have  we to do with hydrogen to solve
the difficulty, when we  know that the base  has
combined with its maximum of oxygen, and there-
fore cannot burn.
   The professor has attempted to prove the  im-
portance of hydrogen in the formation of acids,  and
has called it  a sine qua non of acidity.   The sup-
position that hydrogen is an agent in acidification is
not new;  and 1  believe it should  be ascribed to
some one who wrote  previous to Dr. Priestley.
This illustrious character in some of his writings,
has hinted at something of the kind.   In the  4th
volume of the American Philosophical  Transacr
tions,  Dr.  Priestly says  " Both iron and zinc, es-
pecially the latter, give out much inflammable air
in pure water, and yet that water acquires  no  aci-
dity."  From this it would appear that the ques-
tion had been argued long ago, but that Dr.  Priest*
ley did not believe hydrogen so indispensable to
acidity, even when evolved in large quantities. 
              on Combustion, He.           185
  I agree with the profesor, that oxygen is not the
sole cause of acidity;  nay I go further and have
already endeavoured to prove such a thing impos-
sible.
  " Hydrogen"  says the Professor " is one of the
simple combustibles;  indeed the only one."  But
I am induced to  believe that there is as good rea-
son  for  calling  carbon  a  simple  substance.   I
would ask, what progress is made  in science, by
labouring to prove  hydrogen a sine qua  non of
acidity; since in whatever compound it necessari-
ly exists, it must be  a sine qua non of that com-
pound.  But hydrogen does not exist  in all acids,
therefore the  term of sine qua non as applied to this
cannot extend to all acids.  In oxalic, malic acids,
&.c. we find  oxygen; carbon and hydrogen, each
of which is absolutely necessary to form these acids.
Now I might say with propriety, if the professor's
argument be  solid, that carbon  is a  sine qua non of
acidity,  because forsooth, I find it  in  a few acids;
yet carbon does  not exist in all  acids, neither does
hydrogen.
   The professor says " the reason why  oxygen
and  hydrogen when  combined, do not form an
acid, is because a base is  wanting."   But  this I
conceive, is an unfair mode of  reasoning, since all
circumstances should be taken into consideration.
Air. Davy has supposed that nitrogen is an oxide
of hydrogen, and I believe the professor embraces
this sentiment.
   Dr. Priestley, long ago, was of the same opinion,
 and supposed that nitrous acid was  formed by 
18,6          Analysis of an Essay
oxygen combining with the hydrogen existing in
the compound nitrogen.   So that if the professor
would only adopt this sentiment, he would  then
have one objection to his theory, obviated: that of
nitric acid being supposed to contain no hydrogen.
  " The frequent  suppositions" says our autiior,
of hydrogen being the base of muriatic acid, at least
render it probable  that it enters its composition."
Why to be sure, if supposition is to be the means
of proving a point  so difficult of solution,  it would
be no difficult matter to prove any thing however
absurd.
  Supposition  was the reigning epidemic in the
days of alchemy, but how little did it effect in the
desirable object of converting metals into gold!
with respect to the simple nature of oxymuriatic
acid, I need only say that Mr. Murray has satisfac-
torily confuted this opinion.  In  fact the very for-
mation of muriates  by combustion of metals in
oxymuriatic acid gas is sufficient to overturn all
that has been said  in favour of its simple nature.
True,  the professor would  say,  the  oxymuriatic
acid gas contains water and  it is the oxygen of this
and not of the gaseous acid that oxidates a metal
during its combustion.  But then let me ask, pray
why is not the product an  oxymuriate,  and  not
simply a muriate?  this is but  one of a thousand
arguments that might be adduced to disprove the
modem,  yet most ancient  theory of oxymuriatic
acid.
  Potash is said to be an oxide of potassium, and
I will for a moment admit it.   This potassium as 
              on Combustion, He.           187
a metal,  must according to the professor contain
hydrogen; yet when exposed to oxygen, an acid
is not formed, but an alkali, although oxygen, hy-
drogen and a base  be present, as in other cases.
But how does the professor evade this difficulty?
he says, *• if either hydrogen or oxygen be defec-
tive, acidity does not  result;  if by any means, the
hydrogen be displaced by oxygen, the property of
alkalescence becomes apparent."  This is begging
the question indeed.  A favorite position  is  first
laid down, and then arguments are  suited to the
particular circumstances of the case.  For the pro-
fessor does not attempt to prove by experiment,
that hydrogen has been displaced by the oxygen;
but the formation of an alkali and not an acid from
potassium, would better favor this conclusion, and
hence the inference is made.
   The professor acknowledges ammonia an ob-
jection to his theory,  because in it are found oxy-
 gen, hydrogen and nitrogen: yet no acid is form-
 ed.   But I would beg leave to remark that this is
 not the only instance in which these three substan-
 ces combine without  producing acidity.  For ex-
 ample ;  in vegetable  ox ids, as sugar, we find oxy-
 gen, carbon and hydrogen.  These cases, however,
 are easily explained by the  antiphlogistic  system,
 which regards the  formation of water, oxides, and
 acids, as the mere  combination of oxygen  with
 different bases, invariable proportions.
   The professed object of the essay under consi-
  deration is to reconcile  the contending theories,
  and thus to make a kind of  tertium quid of the 
188           Analysis of an Essay
Phlogistic  and  Antiphlogistic systems.  But I
must stand opposed to such an union, conceiving
it to be by no means justifiable or useful.   There
is nothing in my opinion radically wrong in  the
whole antiphlogistic system, except  it be, the ad-
mission of a principle  of acidity.   Its  principles
embrace every thing relative to metals and their
oxides, which Mr. Davy has investigated.   Why
should we admit the phlogiston of former days of
the hydrogen of modern times, which are the same,
as necessary in all cases, either to acidity or combus-
tion? or rather, why should we yield  opinions con-
formable to correct philosophy, and take in their
place, a mongrel sort of theory, which has neither
reason nor truth to support it?  I believe acidifica-
tion to be one of the most intelligible processes in
nature or art. What is an acid, but an assemblage
of several kinds  of matter, so arranged as  to con-
stitute an homogeneous compound. And is it ask-
ed, to what I attribute the  difference in acids ? I
answer, it is dependant on the variation in quantity
of the different matters entering their composition.
It has been conjectured and that with some proba-
bility, that all matter was originally capable of be-
ing resolved into three great constituents, oxygen,
metallic base and electricity.   Hence, if  this  be
true, we may attribute the immense variety in acids
to the infinite modifications of these original sub-
stances.  We see something like this on a smaller
scale, in the different  compounds of nitrogen and
oxygen, and in many other cases. 
on Combustion, He.
187
   The description I have given of an acid, besides
being  simple,  is  adequate to  explain  all  the
phenomena of acidity in different acids.   Oxygen
has been  deemed so  indispensably  necessary
to the  formation of  an acid, that  some acid bo-
dies have been considered as  anomalies  because
oxygen could not be detected  in them.  Now the
view I have taken of the subject will obviate this
difficulty entirely.  For although  I believe that
oxygen does probably exist in every body possess-
ing acid properties, yet I do not consider that opi-
nion impaired by one or two apparent exceptions,
in which oxygen has not been  found. Prussic acid
is said to be a compound of carbon, hydrogen and
nitrogen, each of which is equally indispensable to
constitute it an  acid.  Now one of these is as much
entitled to  the  appellation of acidifying principle,
as the other, if such a term were at all philosophical.
But it is sufficient to  know that these articles un-
der certain circumstances of  quantity  and condi-
tion are capable of producing  prussic acid.
   When men pretend to reason  in science, they
should  reason as philosophers.  There are a thou-
sand circumstances within the sphere  of chemis-
try, which would appear absurd, were  I to reason
without some little  regard to the philosophy of
the science.  Thus I would suppose it impossible
that two gaseous bodies could by union, produce
a solid, or that  two solids by simple trituration
could be converted into a fluid.   But reasoning as
I ought, these  otherwise  apparent impossibilities,
are no  more than mere common place occurrences.
                       B  b 
188         Analysis of an Essay
   With regard to an inflammable principle, I think
proper to say that there is  as  little reason for re-
taining it as the principle  of  acidity.   Hydrogen
as well as oxygen would seem according to the
professor, to be a sine qua non of combustion, as
well as of acidity. But pray, why not call the com-
bustible itself a sine qua non of combustion ?  for I
believe no one supposes the process can go on
without it.  Matter,  we know has a capacity to be
acted upon, but not a principle of action.  An al-
kali has a capacity of being converted into a neu-
tral salt, by union with an  acid, but it contains no
principle of a neutral salt;  and with as much logic
may it be said,  that a combustible  contains  no
principle of combustion, or inflammability in itself.
What is  a neutral salt, but the result of the mutual
action of an acid and an alkali? and what is combus-
tion, but the effect of themutual operation of oxygen
gas, in some shape or other, and a combustible? The
reasoning in both cases is conformable to the opinion
of philosophers, that matter has a capacity of being
acted upon, but that it cannot be its own mover.
If oxygen gas and a base produce acidity, why can-
not oxygen gas and a base produce also the  phe-
nomena  of combustion?  why in the one case
should we call to our aid an agent as indispensable
when in the other we explain the process by more
simple means ?  The difficulties started are ideal,
and like Phlogiston itself cannot be demonstrated
or even rendered probable. 
             on Combustion, He.            189
  With these remarks I leave the essay for the pre-
sent.   Let the  curious examine and judge accor-
dingly.  "Knowledge"  says  a great  man, "is
power;"  and error in science is its greatest curse.
The road to truth may be long and tortuous, but
he that gains admission into the noble edifice, will
never look back with regret, on the difficulties he
has surmounted ; on the contrary they will serve
as a lasting source of gratification, and add new
lustre to  his triumphs. 
EXPERIMENTS AND OBSERVATIONS
ON  PUTREFACTION.
By John  Manners, M. D,
     FROM reading a paper upon the vinous and
putrefactive fermentation by Gay Lussac in a late
number of Nicholson's Journal, in which the author
according to the general opinion of chemical philo-
sophers, contended that the access of atmospheric
air or oxygen gas, was a sine qua non of the pro-
cess, I was induced to institute the following ex-
periments on putrefaction ; by which I have pro-
ved (as I conceive) beyond the possibility  of ex-
ception, that oxygen is not only unessential to the
putrefactive fermentation, but has, when in actual 
               Experiments He.            191
contact with the putrefying substance no influence
on that process.
  August 10th 1812 I secured some fresh  mus-
cular flesh (a portion of lamb) in the bottom of a
glass jar and inverted it over distilled  water, ob-
serving that the water within the jar, was precisely
on a level with that which was external; that any
absorption of either of the components of the inter-
cluded atmospheric air, might be noted by a cor-
responding absorption of water within the jar.
  Fahrenheit's thermometer stood at 70, at which
temperature it was kept during the experiment.
  That the distilled water was perfectly 'free from
any oxy gen gas, I proved by Mr. Dreissen's method
viz.  I tinged a portion of the same water with lit-
mus and passed nitrous gas through it; which Dr.
Priestley proved would combine with  the oxygen
and  be coverted into  nitric  acid, which  would
change the litmus red.
  Dr. Thomson says, however, that this is not a
critical test, and that the litmus will not be changed
unless there be an  unusual quantity  of oxygen
gas present.
  Upon the discovery of this property of nitrous
gas by Dr  Priestley he founded the first eudiome-
ter,  which has been since improved by Falconer,
Fontana,  Cavendish,   Ladriana,  Magalan,  Van
Humboldt, Ingenhausz, Dalton and Gay Lussac,
and  contributed so much to extend the bounds of
phil sophical knowledge. Before this important era
the only eudiometer in the hands of the philosopher
was a sparrow, a mouse, or a  taper.  Since, how- 
 192             Experiments
ever, others have been devised, as the sulphuret of
iron by Scheele the hydro-sulphuret of potash by
De Marti, the rapid combustion of phosphorus by
Humboldt  and Seguin, the slow combustion of
phosphorus by Berthollet, the green  sulphate of
iron impregnated with nitrous gas by Mr. Davy,
and the detonation of hydrogen gas by Valta.
  The jar remained three days, during which time
the ftesh had undergone the putrefactive process
as was evinced by the offensive odour  emitted.
But at no time could I observe any absorption of
water within the jar : except there was a corres-
ponding reduction of atmospheric temperature, and
in consequence a condensation of the intercluded
air.  But Dr.  Priesttley in a similar  experiment
found a small augmentation of air within the jar:
as I have in subsequent experiments.
  The confined air was analysed with the eudio-
meter  of Humboldt, but not found to differ from
atmospheric air, in the proportion of it pxygen, and
nitrogen.
  The state of the barometer, however,  was not
attended to in  this experiment, which renders it
liable to exception.   Neither did Dr. Priestley at-
tend to the state  of the barometer  in his experi-
ments ; or if he did, he omitted to mention it.
  I repeated this experiment over  the mercurial
bath.
  The thermometer as before stood at 70, and the
barometer at 29,1 inches.
  The experiment was continued three days, when
the putrefactive  fermentation had  taken place, as 
on Putrefaction.
193
was evinced by the odour emitted:  But there was
at no time any absorption of mercury within the
jar.
  Upon examining the included air after the ex-
periment with the eudiometer, it was not found to
differ from atmospheric air.
  But to magnify and render more conspicuous,
any absorption in consequence of a diminution of
the included atmospheric air, by the combination
of its oxygen with the animal flesh, I invented an
instrument which I shall now describe.
  I took a cylindrical
bottle   (A)  perfectly
transparent, and  put
half a pound of muscu-
lar  flesh (a portion  of
the diaphram of a bul- ^
lock) in the bottom of
it, and secured it there.
(B) The flesh was ta-
ken while warm and
cooled  under mercury
to  prevent the access
of air.   To the bottle
was adapted  a  cork
which  was perforated,
and a bent tube passed thro' the perforation,  the
other end of which was hermetically sealed.  (E)
Some mercury was then put into the bottle;  the
bottle corked,  and made perfectly air tight by lu-
 
194             Experiments
ting  and sealing.   The bottle was now inverted.
The mercury filled about two inches of the neck of
the bottle, (D) and was made to pass up the glass
tube by heating it, and expanding the air and thus
expelling a portion of it,  to a proper distance.  (F)
In this situation the bottle was put to rest in a fixed
position.
   A thermometer (I) was included within the bot-
tle m order to note its temperature.
   The bottle and curved tube in some measure re-
presented Mr.  Leslie's differential thermometer.
Here barometrical influence waspeifectly excluded.
And as  the variations in the temperature equally
affected both the air included in  the tube, (G) and
that in the bottle, (C) it is evident that thermome-
trical influence could not effect the experiment.
   To the tube was adapted a  graduated  scale
which would mark any rise or fall of mercury in
the tube.
   Now it is clear that the smallest diminution of
air in the bottle would be marked by a correspond-
ing fall of the mercury in the tube, the  calibre of
which  was not more than one  line.  Or  on  the
contrary, any evolution of gas would raise the mer-
cury in the tube.
   The apparatus remained three days  without any
change of mercury in the tube.  On the fourth
day the  mercury  began to rise and continued to
rise untill the experiment was suspended ; which
proves that there was no absorption of oxygen  gas
by the putrefying  substance. 
on Putrefaction.
195
 The thermometer included in the bottle stood at
60 during the experiment.
  This apparatus is easily constructed and may be
used for many similar purposes, as a gasometer.
  As from all these experiments it appeared that
no oxygen gas  was absorbed  by the putrefying
substance, I determined to exclude the atmosphe-
ric air altogether.  This I attempted first by the
ollowing experiment.
  I put some fresh meat into an eight ounce phial;
filled it with mercury; placed it in  the pneumatic
cistern; it was then filled with carbonic acid.
  In  this situation it was kept three days,  at the
end of which period the flesh was  found to have
undergone the putrefactive fermentation : though
all air except carbonic acid was excluded.  Yet
Sir John Pringle and Dr. Mc Bride (and the latter
from actual experiments) contended for the anti-
septic powers of fixed air.  The thermometer du-
ring this experiment stood at 70.
  But as my  object  was  to  exclude  oxygen
gas, and as carbonic acid contains that as one of its
components, I thought it not impossible but that
the animal matter might abstract a portion of the
oxygen from the carbonic acid, and convert it into
carbonic oxyde : as is the case with iron, zinc, tin,
and certain other metals.
  I therefore repeated the experiment in  every
circumstance, as before, except that I substituted
hydrogen for  carbonic acid gas, but with precise-
ly the same result.
                      C  c 
196              Experiments
  Putrefaction went  on as well as in any  of my
former experiments.
  I.tried sulphuretted hydrogen and nitrogen gases
in the same manner with the same result.
  I then fell  upon a second method of excluding
atmospheric air and oxygen gas.
  1 took an eight ounce phial and put six  ounces
of fresh beef (a  portion of the  diaphram) in  the
bottom  of it,  and secured it there.   In procuring
this beef I was so careful as to go to the butchers
myself and have  it cut  off the moment the animal
was dead.  Upon this meat while thus warm, and
not affected by the external air, I placed a column
of mercury by filling the phial with that fluid.
  The  phial was corked  and to the cork was
adapted one leg  of a syphon which perforated the
cork;  all was  made perfectly  air  tight  by
luting and sealing wax.  The  syphon was filled
with  mercury  completely, and passed into  the
mercurial  cistern.   Over this  was placed a glass
vessel filled with mercury and inverted; in order
to collect any gas that  might  come over.  There
was  now a complete  column of  mercury from
the meat to the top of the vessel inverted  in  the
cistern.  My object in  the first place was to prove
by the first phial containing the meat covered with
a column of mercury,  whether putrefaction could
take place in  that situation where the possible ac-
cess of air was cut off  by the mercury.  My ob-
ject  with the syphon and other apparatus was to
collect  and examine the product, if putrefaction
proceeded. The thermometer stood during this ex- 
on Putrefaction.            197
periment at 70.   In about three days the putre-
factive process was evidently going on.
  These experiments were sufficient to satisfy me
that atmospheric air or oxygen gas, is so far from
being  essential to putrefaction, that it has no in-
fluence on that process when it has free access to
the putrefying substance.
  I mentioned to my friend Dr. Thomas D. Mit-
chell my experiments and their result, who has
since repeated and confirmed them.  He has also
extended those experiments to the vinous fermen-
tation, but the result of his experiment on this sub-
ject, he is not yet able to determine.
  I therefore agree with Dr.  Mitchell that putre-
faction depends on a distruction of the equilibrium
of  attractions  which exists  in the   elementary
principles  of  which the animal substance  is
composed in a healthy state, occasioned by the loss
of vitality in consequence of which new composi-
tions and decompositions ensue.
   My next object was to examine the products of
putrefaction which had taken place without extrin-
sic oxygen.
   The first product was a bloody scum.  The se-
cond was a transparent gas, possessing the  trans-
parency, elasticity, dilatability,  eompresibility, and
other  mechanical properties of atmospheric air.
   As  the gaseous products of putrefaction had
 never been collected and  chemically  examined  I
 thought it an object of importance to give it a careful
 and critical zivdy^s. 
198            Experiments, He.
   I therefore proceeded to examine it in the fol-
lowing manner.
   As it has-been the unanimous opinion of chemi-
cal philosophers who have written on the subject,
that ammonia is generated and is the principle pro-
duct of the putrefactive process, I first tested it for
that substance.
   1st. By passing a peice of litmus paper reddened
by vinegar into a vessel about half filled with this
gas over mercury ;  no change ensued.
   2d.  Some of the  gas was passed through an in-
fusion of litmus reddened by vinegar;—no change.
   3d.  I filled a vessel with mercury over the mer-
curial bath and displaced about half of it by passing
up an infusion of  litmus  reddened by  vinegar.
After which I passed up the gas, which was readily
absorbed untill it was strongly impregnated and
the gas had accumulated in the top of the vessel;
—no change.
   4th. ^th.  6th. I tested it  with turmeric  in all
the three ways  in which  litmus reddened by vine-
gar was used;—no change.
   7th.   I  passed  up a piece  of  wet sponge by
means of a wire but there was no perceptable ab-
sorption  of the  gas  by the water contained  in the
sponge.
 8th.  The sponge was withdrawn and washed
in a solution or sulphate of copper;—no change.
   9th.   I  passed a solution  of sulphate of cop-
per into a vessel filled with mercury over the mer-
curial cistern untill  it  was two thirds displaced by
the solution of copper.  I then passed up the gas 
               en Putrefaction.            199
until the substance  was  thoroughly impregnated
with it and had accumulated in the top of the vessel;
—no change.
  10th.  Carbonic acid was passed up into a ves-
sel containing this gas; no  chemical change, (ex-
cept we call, with Mr. Berthollet, the admixture
of gases, chemical dissolution.)  The  carbonic
acid produced an augmentation of the bulk of the
gases proportional to its quantity.
  11th.  Muriatic acid was passed up into a ves-
sel filled with this gas over mercury;—no change.
  These experiments  were abundantly  sufficient
to prove that there was no  ammonia in the pro-
duct of putrefaction at least when  it takes place
without the influence of external causes.
  Secondly, I tested it for oxygen in the following
manner.
   1st. A piece of phosphorus was passed up into
a vessel filled  with this gas, and  standing over
mercury.  The  phosphorus was  fused, and be-
came perfectly fluid, (floating upon the surface of
the  mercury,) by pouring boiling water upon  the
vessel.  But there was not the slightest appearance
of combustion.
   2d. Water was now passed into the same vessel
which was tested for phosphoric acid by  litmus;
no change.
   3d. Nitrous gas  was  passed  into a vessel filled
with this gas over mercury ;  no change,  except
in the bulk, proportional to the gas added.
   4th. Water was now passed  up into the same
 vessel  and tested for nitric acid by litmus;  no
 change. 
200             Experiments
   5th.  A mouse was passed into a vessel  of this
gas, which instantly died.
   These experiments were deemed sufficient to
prove the non existence of oxygen.
   Thirdly, It was now tested for sulphuretted hy-
drogen.
   1st. A piece of silver was placed in a vessel of
this gas which was not blackened or converted in-
to a sulphuret, when withdrawn.  A piece of sil-
ver*Was  also  kept in water  highly impregnated
with this gas, and another piece  was placed at the
end of the tube from which the gas was disenga-
ged and with the same result.
   2d. The gas was passed through a solution of
nitrate of silver;—no change.
   3d. A vessel was filled with mercury over the
mercurial trough, and displaced by passing up a
solution of nitrate of silver untill the vessel was half
filled widi it.  After which the  gas was permitted
to pass up, as it was disengaged from the putrefy-
ing substance through the mercury and through
the solution cf silver until it was strongly impreg-
nated with  it  and had accumulated in the upper
part of the vessel;—no change.
   4th. This gas was passed through a solution of
sugar of lead (acetas plumbi) in the same manner
as experiment 2d. no change.
   5th. A solution of acetate of lead was impregna-
ted with the gas in the same manner that nitrate of
silver was in experiment 3d.;—no change.
   These tests were sufficient to  prove that  no sul-
phuretted hydrogen was formed. 
on Putrefaction.            201
  Fourthly, I tested it for carbonic acid.
  1. By litimus paper;  reddened.
  2. By passing the  gas through  a  solution of
litimus ; reddened.
  3  I passed up a portion of an infusion of litmus
into a vessel filled with mercury until the mercury
was three fourths displaced and then passed up the
gas from the putrefying substance;—the litmus
was reddened.
  4th.  I filled a vessel with mercury over the mer-
curial bath and passed up lime water. After which
I passed up the putrescent gas.   The lime was
precipitated.
  5th. The precipitate obtained in a number of ex-
periments, effervesced with  acids as the muriatic,
sulphuric,  nitric, oxalic acids, &c.
   Consequently the gas was carbonic acid.  Pro-
bably holding  a foeted  oil (or some of the animal
matter) in solution, to which it owes  its  offensive
odour.
   From the six ounces of animal  matter I have
 already collected more  than 100  cubic  inches of
 this gas.
  Other professional engagements and the approach
 of cold weather prevented my making these expe-
 riments more complete. But the subject will again
 be  resumed when favourable weather  returns.
 I therefore submit them to the society, imperfect
 as thcv are.
      it 
OBSERVATIONS
 On the formation of muriate of potash in the pro-
   cess of preparing the hyperoxymuriate of potash
   by William Hembel  Jun. Esq,,  of  Phila-
   delphia.

     THE formation of muriate of Potash, in the
 process of preparing the hyperoxymuriates of pot-
 ash does not appear to me satisfactorily explained.
 Berthollet supposes, that the oxymuriatic  gas  is
 decomposed during the process, one portion of the
 gas losing the whole of its  oxygen, is reduced to
 simple muriatic gas, whilst the other portion com-
 bines with the separated  oxygene and is converted
 into hyperoxymuriatic acid gas. To me it appears
 m6re probable, that muriatic, as well as hyperoxy-
 muriatic gas are evolved at the same time, during
the effervescence of the muriatic acid and that each
in their disengaged state combines with the dissol-
ved salt, according to  laws, which govern their
respective affinities. 
Observations, He.            203
  When muriatic acid is added to manganese, an
action takes place.  The temperature of the mix-
ture is raised, and oxymuriatic gas is evolved in
proportion to the strength of the  acid employed.
But the action, is not with the whole of the muria-
tic acid employed.  It can only be with the lower
stratum, or as much of the acid as is in  contact with
the manganese.  The supernant acid remains inert
until  the whole, or part of the acid of the substra-
tum is volatalized.   In  fact it appears probable,
that the parts of the supernatant acid are brought
into action, only in proportion as  the substratum
is driven off by the heat of the mixture, or of the
fire employed :  from whence it results that part of
the muriatic acid of the supernatant acid, must rise
along with the oxymuriatic acid gas,  and both
passing into the saturating vessel,  each must com-
bine with the potash,  in proportion to  their respec-
tive  affinity.   The  muriate of potash remaining
in solution, whilst the oxymuriate crystalizing falls
to the bottom of the vessel.
   Further, it appears highly propable, that the pro-
portion of muriatic gas evolved during the process
considerably exceeds the  oxymuriatic for the fol-
lowing reasons.
   The strongest muriatic acid which can be ob-
tained the specific gravity of which is 1.196 con-
sists, according to Kirwan of 25.28 real  acid and
74.72 water.
   Now, as the whole of the acid  affused  over the
manganese, cannot come in contact with that sub-
 stance at the same time, and as the water with
                    D d 
204            Observations, He,
which the acid is combined, remains after the acid is
driven off.  I think it highly probable, that before
the process is nearly finished the acid is too much
reduced in strength, to be capable of disengaging
any oxygen from the manganese.
   To illustrate the above opinion, let us suppose,
500  parts of  muriatic acid, are affused over any
quantity of manganese; and that the 500 parts ofjacid
are divided into 5 strata, distinguished by the let-
ters ABC, DEF, and that the strata acts only in
succession on  the manganese.
   Now 500 parts of the  strongest muriatic acid,
are composed of 373.60 water and 126.40 acid.
Consequently  each stratum would be  composed
of 25.28 acid arid 74.72 water.  Hence, the decri-
ment of the strength of the acid during the process
would be  as follows.
                            Acid.     Water.
   At the  commencement 1
of the process there would r   126.40     373.60
be         f           ■*
  After the stratum A was }
deprived of its acid, there £   101.12     373.60
would remain            '
After the stratum B           75.84     373.60
                 C           50.56     373.60
                 D           25.28     273.60
   E and the remainder, would  be the water with
which  the whole acid was combined. 
ANALYSIS
/
                OF THE



BORDENTOWN  (N. J.) SPRING.
BY SAMUEL F. EARL.
  A small quantity of the water from this spring
was sent to me (some time since) for examination,
when the following experiments were made ; but
business of more importance at that time, before
the Society, restrained  me  from  presenting the
analysis.
  The 1st.  experiment  I made, was with a view
to ascertain whether the water contained any earthy
or metallic  matters;  a solution  of potash was
therefore added, which  gave a brown  tinge and
precipitate. 
206             Analysis of the
  Experiment 2d.  Tinct. of galls changed it to a
purple and black precipitate formed by standing.
  Experiment 3d.  Prussiate of potash made but
little change until one drop of sulphuric acid was
added, when a deep blue color was immediately
produced.
  Experiment 4th.   A portion of  the water was
boiled a  few minutes : tinct of galls now added,
produced no change of color; during the boiling
a yellowish brown precipitate was deposited on the
sides and bottom of the vessel.
  .Experiment 5th.   Sulphuric  acid was added,
which caused  an effervescence,  or extrication of
gas.
  Experiment 6th.   A solution of acetate of lead
produced a white precipitate by standing.
  Experiment 7th.   A solution of the muriate of
barytes:
  Experiment  8th.  A  solution  of  the nitrate
ofsilver:
  Experiment 9th.   A solution of the oxalic acid,
were all  separately added, but made no percepta-
ble change.
  Experiment 10th.  I evaporated to dryness, 8
ounces of the water; the residuum weighed 2.75
of this 1.00  was  an oxyd  of iron ;  the remaining
1.75 I infered from the preceding experiments was
earthy matter.

            RECAPITULATION.
  The first experiment proved the water contain-
ed earthy or metallic bodies in solution. 
             Bordentown Spring.          207
  Experiments 2d. 3d. fully proved this metallic
body to be iron  (the sulphuric acid was added in
experiment 3d. to saturate, if present, any uncom-
bined earth.)
  From experiment 4th. I found the acid which
held the iron in solution, to be volatile.
  Experiments 5th. and  6th.  proved  beyond  a
doubt, this volatile acid was the carbonic acid gas.
  Experiment 7th. 8th. and 9th, the first, a test for
sulphuric  acid, the  second for muriatic  acid, and
the last for lime, proved their nonexistence.
  By experiment 10th. I found 1 pint of the wa-
ter contained 2 grains of an  oxyde of  iron, a far
greater quantity than the Pyrmont or  Chelten-
ham, both celebrated chlybeates.  Not having any
litmus, I inferred from the circumstances attend-
ing drinking the water, that it contained a large
qusntity of uncombined carbonic acid.
   From a review of this analysis,  I think  we may
justly rank the  water  of the Bordentown Spring,
 among the  highly carbonated chalybeates of the
 United States* 
REPORT
 Of the Committee to'whom was refer ed the  analy-
   sis of certain ores, presented through the medi-
   um of Thomas Brientnall Esq. to the Columbian
,  Chemical Society.

 Mr. President,

     YOUR committee taking into consideration,
 the many troublesome and tedious processes, at-
 tending an accurate analysis ; the very small quan-
 tities of the specimens,  and also being told, that the
 wish of the gentleman who presented them, was
 not a knowledge of the  component parts, and exact
 quantity of each part, but of that (if any) with its
 quantity, which could  be worked to advantage,
 report as follows:
  Specimen No. 1.  Granular  and very brittle;
 color  brownish  black, interspersed with  small
specks resembling the Hematites.   When  pow- 
                 Report, He.              209
dered, attracted by the magnet specific  gravity
3.817. Aboat two ounces of the acid muriatic were
poured on fifty grains finely powdered, and after
digesting a sufficient  length of time, decanted;
fresh portions of  the acid were repeatedly added,
until by testing it with the prussiate of potash and
the tinct. of galls, it was found no more of the ore
could be taken up.  The several decantations and
washings, were then mixed, and saturated with a
concentrated solution of the  sub. carb. potass, by
which process the oxyd of iron was  precipitated,
together with a small quantity  (hardly perceived
by the addition of the  aq. ammon.  or immersing
polished iron) of copper. The precipitate thus ob-
tained was dried,  and subjected in a crucible (with
powdered charcoal,) to a strong heat; after cooling
it  was carefully taken out, and  now weighed 49\
grains, equal to 35 grains of metallic iron.
   Specimen No.  2.   Very  compact,  and  sono-
rous, of a dark slate color; specific gravity 4.020.
   Twenty five grains finely powdered, were put'into
one ounce of the acid muriat. then digested and de-
canted:  as before a few drops of this solution, were
mixed with a wine glass of water, and the ; q. am-
mon. added, ammoniaret of copper was formed im-
mediately.  The  sol. pruss. potass, was then add-
ed in the same manner as the aq. ammon. and pro-
duced a  blue color (or the pruss. Ferri.)
   The whole solution was saturated as that of No. 1
with the concentrated solution of the sub. carb. po-
tass: the obtained precipitate,  after drying, was re-
dissolved in the acid.muriet. The cupreous portion 
210             Reports,  He.
of the solution amounting to 4\ grains was taken
up by polished iron, 22 grains of the ferruginous
oxyde were left,  which gave 1534 grains of metal-
lic iron and 4\ of copper.
  No analysis was made  of the remaining speci-
mens ; their  specific gravity, being so low, (none
exceeding 2.300) and to appearance, precisely the
same nature as specimen  No.  1.

                        SAMUEL  EARL.
Aug. 19th. 1812. 
REMARKS
ON  THE ATMOSPHERE.
Read before the Columbian  Chemical Society,  by
  Thomas D. Mitchell M. D.  Fellow  of
  the Academy of Natural  Sciences of Philadel-
  phia. Honorary member of the Columbian Che-
  mical Society of Philadelphia, He.

    THE discussion of subjects, respecting which
the  opinions have  been various, is certainly of as
much  importance,  as speculation on a new to-
pic.   In the one case, we have presented to us the
ingenuity and industry of the many who have pre-
ceded us, while in the other we  have no better in-
ducement to an exertion of talents, than the fanci-
ful hypothesis  of some daring spirit of research.
                     E e 
212                Remarks
What then is our prospect in either case ? If una-
bating zeal for the truth  profit us not on the one
hand, we are as apt to be perplexed and disappoint-
ed on the other.  But while  I  argue for the im-
portance of repeated  investigations of antiquated
subjects, I am not  the less sensible  that as truth
possesses but one front,  we  should be indifferent
in what path we direct our steps to obtain it.
   These remarks having been  premised,  I beg
leave to call the attention of the  society a few mo-
ments to the subject of the atmosphere.
   It may not be amiss to inquire in this place what
is meant by the atmosphere in contradistinction to
atmospheric air.   For however strange it may ap-
pear, there are those who  consider the one  as dis-
tinct from the other.  By the atmosphere,  I mean
that fluid mass apparently homogeneous in its nature
which is found on every part of the earth we inha-
bit ; the properties of which are levity, elasticity,
 invisibility, &c. &c.   This acceptationjof the term
is perhaps universal, yet some define atmospheric
air differently.  It is said to consist of nitrogen
and  oxygen only and that carbonic  acid gas &c.
are merely adventitious.   But as the term gas has
been substituted for that of air, it seems most cor-
rect to give to each of the gases in the atmosphere,
the  name of atmospheric air.  Nor is there any
impropriety according to this arrangement  in call-
ing the whole mass, atmospheric air.   For as each
different gas in the atmosphere is necessary to con-
stitute  the mass itself, so  each must be an  atmos-
pheric air. 
              on the Atmosphere.           213
  The point more particularly to be investigated
is, whether the atmosphere is a simple mixture, or
a chemical compound.  This though apparently
a subject  not  difficult  of explanation,  has been
much disputed.   What are the grounds for sup-
posing it to be a simple mixture ?  It has been said
that a separation of the gasses oxygen and nitrogen
ensues after a considerable lapse of time, if rest be
allowed.
  Again it has been asserted that the same given
quantities of oxy gen and nitrogen would, under dif-
ferent  circumstances produce the very opposite
compounds of nitric acid  and atmospheric air.
The two compounds being so widely different and
no one having denied the ©ompound nature of ni-
tric acid, the atmosphere has been jdeemed a sim-
ple mixture.   Let us for a moment test these by
hypotheses.
  In the first place then I ask, is the supposed se-
paration of the component parts of the atmosphere
a case of simple disunion, or chemical decomposi.
tion  ?  I am of the latter opinion.  We are told that
a quantity of atmospheric air by long standing in a
confined place, evinced a separation of its constitu-
ent parts, and that nitrogen and oxygen were found
in the vessel in a separate state.   But what does
this prove ? It is in my  opinion an argument in fa-
vor of the compound nature of the atmosphere,
that  is of its chemical composition.  True, no evi-
dent means, no manual efforts were made use of
to effect a separation.  But why  are  the repeated
changes of temperature disregarded, why the den- 
214
Remarks
 sity of the air unnoticed, and why the never ceas-
 ing agency of moisture  and dryness neglected to
 be mentioned ?  Are these of no consequence in
 chemical research or is their importance so trifling
 as not to merit the least attention ? By no means;
 every circumstance however trivial it may appear,
 is ultimately of the greatest magnitude, and should
 never be forgotten.   What shall we say of the de-
 oxidation of metallic salts when kept  in a situation
 exposed to  the  light ?  Are  these not  chemical
 compounds ?  No  one  pretends  to  call them
 simple mixtures, and yet thedeoxidationisnotthe
 effect of mechanical operations, the powers of in-
 creased heat or of double decomposition from mix-
 ture with other bodies.   In such cases there is of-
 ten an actual separation of the  oxide from the acid
 with which it was combined.
   Again ;  the opposite compounds said to be pro-
 duced under different circumstances from the same
 quantities of nitrogen and oxygen; have been addu-
 ced as an argument in favor of the opinion that the
 atmosphere is a simple mixture.   But what sup-
 port  can this give ?  Surely none.   In the first
 place I deny the  position, since it has  not been de-
 monstrated that the same quantities of nitrogen and
 oxygen  do under  different  circumstances  ever
 produce the compounds atmospheric air and nitric
 acid.   But even admitting  the truth  of the posi-
 tion, it argues nothing in favor of the opinion it is
 designed to support.
  The gasseous oxide of nitrogen is, as all know?
i compound of the  same gasses of  which nitric 
              on the Atmosphere.           215

acid is formed.  Yet rto one has absurdity enough
to imagine that nitrous oxide gas -i* less a chemical
compound  than nitric acid.   And are their pro-
perties the same? By no means.   This ought to
be the case howvever, if the reasoning formerly
alluded to  were correct, viz. that when two sub-
stances diametrically  opposite to each other are
formed from the same ingredients, one  of them
must be  a simple mixture.   The fallacy of this
reasoning however is obvious, as  the premises,
themselves are false.  V
   Having briefly considered the arguments,' in fa-
vor of the simple nature of the atmosphere, I shall
now offer some remarks calculated to prove that it
is in fact a chemical compound.',
   The laws of attraction have  been divided by
chemists into several orders.
   It is my intention here however to premise that
there are properly but two  kinds of attraction, viz.
That by which particles of matter whether simi-
lar or dissimilar are united independant of a chemical
change in either body.   It may be called adhesive
or cohesive attraction, the  former of which .terms,
I prefer.   The other species is that by which par-
ticles of matter are  united and a total  change-.of
 properties affected. It is called chemical attraction.
 Now  under one or other of these kinds of attrac-
 tion, all the operations of nature  must be included
 Let us for a moment apply these .remarks to the
 subject under consideration.
    Is the atmosphere a simple mixture of particles
 dissimilar in their nature ? What says the law of che- 
216                Remarks
 mical action ? It tells us that the bodies submitted
 to  its operation have  their properties changed.
 What then are the properties of nitrogen and oxy-
 gen in a separate state and what are the peculiari-
 ties of atmospheric air ? If none of the peculiar
 properties of nitrogen exist in  the compound at-
 mosphere of which it is a part, then it follows that
 a chemical action has ensued by its combination
 with oxygen, otherwise the law of chemical action
 is made void.
  Nitrogen gas is fatal to life," and will not support
 combustion.  Atmospheric air is the  grand vehi-
 cle of existence and an indispensable agent in the
 production of flame.
  I doubt whether there can be such a thing as
 simple mixture, that is a union of two bodies, in-
 dependent of all the collateral circumstances which
 influence chemical action ; If there be indeed such
 a thing, I believe there is no better instance of it
 than the mixture of hydrogen and nitrogen gasses.
 By  adding a  portion of  hydrogen gas to another
 portion of  nitrogen, we produce no change in the
 properties  of either Unless the  electric spark or
 some such agent be called into operation.   They
 immediately arrange themselves according to the
 specific gravity of each.
  But the case is very different with oxygen and
nitrogen.   Here a perfect union is speedily effect-
ed and the peculiarities of the components are lost
in the compound.
  I think from what has been said in investigating
this subject, it is plain, that if chemical  action be 
              on the Atmosphere.           217
exerted in any case, and if a change in the proper-
ties of bodies placed in contact with each other, be
a proof of such  action, then is the atmosphere  a
chemical compound and not a simple mixture.
  If  we should be disposed to admit the simple
nature of the atmosphere, we would then  be obli-
ged to class it under the list of examples of cohe-
sive attraction.
  But how  should we be able to reconcile  this
with the generally received  definition of cohesive
attraction.   It is said to be that kind of affinity by
which similar particles of matter are united. Now
oxygen and nitrogen are dissimilar in their nature,
of course, according to the above definition, the at-
mosphere could not be a case of cohesive attraction,
and consequently  not a simple mixture.
   Hence it is obvious that^as oxygen and  nitrogen
gases are different  in their properties, if a union
can take place between them, that union cannot be
simple.  How could it possibly  be simple, since
in all cases  in which two or more bodies unite, so
as to lose entirely their characteristic properties, a
chemical action is necessarily implied.
   I have purposely omitted the   consideration of
the carbonic acid  gas found in the  atmosphere ;
for if the remarks already  made respecting oxygen
and nitrogen be just, they  are  equally so when
applied to carbonic acid gas. The subject is  plain
 in itself and requires but a small share of investiga-
 tion  to satisfy the  most sceptical in science. 
A NEW METHOD  OF MOUNTING
     WOULF'S  APPARATUS,


In which the tubes of safety are superseded, by
   William Hembell Jun. Esq.   Communicated t%
   the society by John Manners M. D.

             Philadelphia November 20th, 1812.
Doct. Manners,
              Sir,
                   1 inclose for your inspection,
a method of mounting A.  Woulf's apparatus in
which, tubes of safety are totally unnecessary.  If
it should meet your approbation, please to present
it to the Columbian Chemical Society.
       I remain Sir,
                   Your Friend,
                       Wm. Hembell, Jun.

    THE utility of Wou f s apparatus, is conside-
rably diminished by the necessity of a tube of safe-
ty ; if streight tubes are used, the liquid is forced
out of the bottles, whenever there is a considerable 
A New Method, Ha          219
accumulation  of gass, whilst Welter's tubes are
so costly and delicate in their structure ; that they
can scarcely be handled, without danger of break-
ing.
   In the Frontispeice is exhibited a manner of con-
necting any number of bottles, by which the escape
of gas is prevented, and the danger of contamina-
tion is obviated, without the necessity of tubes of
any description.
   The tube H, merely perforates the corks, w th-
ou! descending into the receiver  A, or bottle B-
Thetube I,  descends nearly to the bottoms o  ne
bottles B and C.  K  only perforates the co:  Sj
L descends  nearly  to the bottoms of the bottles)
D, E, F & M only perforates the corks, whilst N
descends nearly to the bottoms of the bottles F and
 G.  A similar arrangement of short and long tubes
 are to be used, for any additional number of bottles.
    To  illustrate the advantage, which this manner.
 of  connecting bottles possesses  over  the  usual
 method by tubes of safety,  we will  suppose,  the
 operator wishes to prepare muriatic acid.
    In that case, the receiver A and bottle B are left
 empty ; a  little water is put into the bottle C to
 condense, whatever sulphureous  gas is evolved.
 The bottle D is left empty, and  the water to be
 saturated with the muriatic acid gas; is to  be in-
 troduced into the bottle E.  F is left empty, and
 into G, a further quantity of water is introduced;
 to condense the gas, which may escape condensa-
 tion in the bottle E.
                        F f 
220           A New Method, He.
  On adding sulphuric acid to the muriate of sor
da, contained in the retort, an action will take place.
The evolved gas, will pass through all the bottles
as usual.
  If, from  engagements or  neglect, the operator
omits to add fresh acid when  the gas ceases to be
evolved, a condensation will take place in the re-
tort.   Then the liquid, in the bottles C E and G,
will yield to the joint  pressure of the incumbant
atmosphere, (acting through the aperture of the
tube O,) and  the  accumulated gass  in the empty
parts of the bottles C  E and G and pass into the
bottles B D and F.  But as the apertures of the
short tubes H K and  M terminate with the lower
ends of their respective corks, the liquid in the
bottles does  not reach those apertures; conse-
quently, it can pass no further.
   After an absorbtion has taken place, it is only
necessary to excite a fresh action in the materials
of the retort, the gas will then accumulate in the rcT
ceiver and empty part of the bottle B.  When the
accumulated gas is sufficient to support a column
of the liquid,  equal to the highest of one leg of the
tube I, the liquid will rise, and pass into the bottle
C, the gas will follow and pass into the bottle D,
and by pressing  on  the surface of the contained
liquid, will force it over into E ;  after which, the
contents of F, will be forced into G, when the pro-
cess of saturation will  go on  as before.
   It will even be advantageous to the process, that
an absorbtion should take place frequently, as the 
              A New Method He.           22 X
surfaces of the liquid will thereby be changed and
the condensation of gas considerably accelerated.
  With an apparatus arranged  as the above, the
writer of this, saturated thirteen pounds of water
with muriatic acid gas ; only that he  substituted
demi-johns, for the bottles D, E, F and G, his at-
tention  being frequently  otherwise  engaged, the
apparatus, was suffered to stand for  three  weeks,
without any injury to the product.
  It can hardly be necessary to remind the manu-
facturer, that  for  nitric or  muriatic acids,  an
iron matrass  may  be  substituted  for the  glass
retort.   In that case, the receiver may be dispens-
ed with, one end of the tube H, being made to en-
ter the tubulure of the matrass,  and  the other end
entering the turbulure of the bottle B.
END OF VOLUME I. 
 
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