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V. 
AN EXPERIMENTAL INQUIRY
                   INTO THE

             SIMILARITY IN VIRTUE

                  BETWEEN THE


CORNUS FLORIDA AND SERICEA

                   AND THE

    CINCHONA OFFICINALIS OF LINNAEUS,

                 TOGETHER WITH


      AN INQUIRY INTO THE MODUS OPERANDI

                      OF

            ASTRINGENT VEGETABLES

                      IN

    PREVENTING THE PUTREFACTIVE FERMENTATION.

       BY JOHN M. Vj^ALKER, ^/

           OF VIRGINIA :

MEMBER OF THE AMERICAN LINNJAN SOCIETY AT
  PHILADELPHIA, AND MEMBER OF THE PHILADEL-
  PHIA MEDICAL SOCIETY.
 Every theory founded upon experiment, and not assumed, is
always good for as much as it will explain.
                                Burke.
               PHILADELPHIA:

PRINTED FOR THE AUTHOR, BY H. MAXWELL, NO. 25, NORTH
      SECOND STREET, OPPOSITE CHRIST-CHURCH. 
 
      AN INAUGURAL DISSERTATION,




                 FOR





            THE DEGREE





                 OP







  DOCTOR OF  MEDICINE j





              SUBMITTED




          TO THE EXAMINATION




                OF THE





REVEREND JOHN ANDREWS, D. D. PROVOST,





            (pro tempore;)




                 THE





   TRUSTEES AND MEDICAL PROFESSORS




                OF THE




      UNIVERSITY OF PENNSYLVANIA,




        ON THE 8th DAT OF JUNE, 1803. 

 
          TO DOCTOR ROBERT WALKER,

                        OF VIRGINIA.

 DEAR SIR,
    IT is not the pleasing recollection of the kind admonitions and
 instructive lessons, nor the lively remembrance of the many disin-
 terested services and attentions which I received from you, while
 under your direction, that alone prompts to this dedication; but it
 is likewise the more pleasing recollection of the  high station in the
 republic of medicine, which your talents, and success in the practice
 of physic, have long conferred upon you.
    Permit me, therefore, to offer you  this, the  first fruits of your
 instruction, as the public mark of my acknowledgment, while my
 heart shall, in secret, ever continue to pay you the still dearer tri-
bute of gratitude, due from
                                  Your Friend
AND PUPIL. 
 
      TO BENJAMIN SMITH BARTON, M.  D.

 PROFESSOR  OF MATERIA MEDICA, NATURAL HISTORY,  AND
       BOTANY, IN THE UNIVERSITY OF PENNSYLVANIA.

 SIR,
   THE objects of dedications are as various as the acquirements
 and qualities of the mind: some are intended to express talents, zeal,
 and knowledge in science; others, benevolence and humanity.  In
 you all these are concentred in an eminent degree. To none, therefore,
 could I with more propriety dedicate  this imperfect  essay, than to
yourself.
                   Accept it then, Sir,
                       As a mark of the greatest respect
                            And friendship from the
                                              AUTHOR. 
 
INTRODUCTION.
       IT was  an opinion early held in Medicine, that
every country possessed an antidote to its diseases.   The
history of the Peruvian Bark tended greatly to confirm this,
and if there be any justness in it, this opinion may be again
revived in America.    For  if Nature has given us, in our
swamps and marshes, a Pandora's Box, she has in our for-
rests given us a Cornu Copia; has she in our vallies sowed
the seeds of disease, she has on our hills planted the Cornus
Florida; or has she, more grievously to us, given wing to the
volatile miasmata, that, under protean forms, attack us in
a thousand ways, she has most providently scattered in our
swamps  the Cornus Sericea.
   But I would not be understood to  overvalue these pro-
vident gifts of nature, in implying specifies.  Conscious of
the short-lived reputation which exaggerated virtues beget
for their medicines, I shall not deal in hyperbole; much less
shall I detract from the Peruvian Bark, its justly accumula-
ted praises,to heighten the blaze of contrast; nor shall I even
introduce from obscurity  into  notice,  inert undeserving
                           B 
                            X
 vegetables:—Already have their virtues been perceived by
 the penetrating eye of professor Barton*.
     I  have only then to shew, upon analytical principles,
 what foundation there is for a similarity in virtue, between
 the Cornus Florida and Sericea, and the red Peruvian Bark.
     The most satisfactory mode of doing which appeared to
 be  that of subjecting the Corni to every experiment, to
 which the Peruvian Bark has been subjected.  The desire
 of utility, and not the love of novelty, nor the merit which
 is generally annexed to it, could have prompted to such an
 analysis; for so many valuable experiments  and observa-
 tions have already been made on the Peruvian Bark, that
 little now remains to be added.  My claim  to indulgence
 must, therefore, rest upon the intention alone, and  not  the
 performance.
    Too long has America paid tribute to foreign countries,
 too  often have her physcians been  baffled  in their practice
 from the adulteration of the bark.   Every attempt, there-
 fore, to liberate us from importation and obviate imposition
 is praise worthy in itself; but how much more so must it be,
 when it is directed to our own, too long neglected treasures.
 Flattering myself that your zeal to encourage such an at-
 tempt, will draw the mantle of forgetfulness over its imper-
 fections, I shall proceed to the investigation of the subject.
 In prosecuting which I cannot follow a better method, than
 the canon of Linnaeus, " Systemate, Qualitate," Experimen-
 ta, " et experientia, eruitur omnis usus plantarum."
   * Vide his collections for an essay towards a Materia Medica of the
United States, page 12. 
      AN  EXPERIMENTAL INQUIRY


                    INTO THE

             SIMILARITY IN VIRTUE

                  BETWEEN THE


CORNUS FLORIDA AND  SERICEA,


                    AND THE

   CINCHONA OFFICINALIS OF LINNAEUS, 8cc.
                   SYSTEMATE.

      J. HE Genus Cornus, to  which the English have
given the name of Cornel or Dogwood, is arranged by
Linnaeus, in the class and order Tetrandria Monogynia of
his sexual system.   In this artificial  system it is associ-
ated with a number of genera, the species of which are
often endued with properties very  essentially  different
from those of the two species of Cornus, which form the
principal objects of this dissertation.
   In his work on the natural orders of vegetables, the
great Swedish naturalist, has arranged the Genus Cornus,
in his forty-seventh order, to which he has given the name
Stellatae, or Stellate plants, a name originally applied by the
illustrious Mr. Ray.   In this order, the Cornus is associa-
ted with a number of genera, some of which are endowed
with highly useful medical,  or other properties.   I shall
here mention the names of some of them; they are Galium,
Rubia, Spigelia, Coffea, and Psychotria.
   In the system of  Mr.  De Jussieu, the Cornus is ar-
ranged in the third order of his eleventh class, to which he 
12
has given the name of Caprifolia.  Some of the principal
genera with which it is here associated, are Lonicera,Trios-
teum, Caprifolium, Viscum, Viburnum, and Sambucus, and
the medical properties of these, as far as we  are yet ac-
quainted with them, are not very similar, to those  of  the
species of Cornus, which are about to claim our attention.
The Viscum,  or Missletoe,  has, indeed, been  recom-
mended by some practitioners, as a remedy in intermittent
fevers, and as a tonic in other diseases.
    The following is Linnaeus's abridged definition  of  the
Genus Cornus:
Involucrum 4....phyllum saepius.  Petala supera, 4....Drupa
                  Nucleo 2....1oculari.
    Of this  genus,  many  species  are now known  to  the
botanists, and of these, several,  especially of  the  North
American  species,  were unknown to Linnaeus; with  the
Cornus Florida, and Cornus Sericea, however, he was ac-
quainted.
    The  Cornus  Florida,  which  is well known in many
parts of the United States, by the name of Dogwood, and
less generally by that of Box-wood, is a very common vege-
table in many parts of North America.   The following
accountof the Dogwood,is taken from an interesting manu-
script copy of the Geographical History of the Plants of
North America,  read to  the American Linnean Society,
by Dr. Barton, president of  said society.   " The  Cornus
Florida grows  as far north as latitude 45° and it extends
as far south as latitude 28°.  It is  a tree of moderate
stature.  It does  not in general attain the  height of more
than from eighteen to twenty-five feet.  Sometimes, how-
ever, it makes a nearer approach to the m'ore lofty trees of
the forests, attaining to the height of at least forty feet, and
near one  foot in diameter." The trunk is strong and covered
with a rough bark, which is much disposed to separate into
longitudinal and transverse fissures, or cracks.  The wood
is extremely hard, and durable.  Hence  it has received 
13
one of its names,  that of New-England Boxwood.  The
branches are  numerous and spreading, -and  sometimes
placed opposite, but frequently by fours, arising from oppo-
site points, and pretty regularly disposed.   The leaves are
oval,  pointed,  entire, and very veined.  The flowers are
produced at the extremity of the small branches in clus-
ters, the individuals of which are more or less numerous.
    They consist  of an involucre, which is  composed of
four very large obcordate folioles, of a fleshy texture,  and
of a fine white colour.  The extremity of each foliole, is
marked by a notch,  which sometimes exhibits the appear-
ance  of having  been bitten.   These  parts of the invo-
lucre are generally of a dusky rose colour.  The flowers,
which are situated in the centre of the large  involucre (in-
volucrum maximum of Linnaeus) are very small and of a
yellowish colour.   The calyx or empalement is monophy-
lous,  or one leafed, very small and four toothed above.  It
is deciduous, or falls off before the ripening of the fruit.
The corolla consists of four petals.   The stamens are four,
and of the same length.  There is one pistil consisting of
a roundish germ, which is inferius or beneath.  The style
is filiform and nearly the length of the corolla.  The stig-
ma obtuse.
    The flowers generally make their appearance, in Penn-
sylvania, and other middle parts of the United States, about
the beginning of May.   They exhibit a most beautiful ap-
pearance ;  the large and white involucre forming a fine con-
trast, with the green of the forest.  They are succeeded by
oblong drupes, commonly called berries,  which are  of a
rich crimson colour.  The berries ripen in September, and
are the food of various species of birds, such as the robin
(turdus  migratorius,) thrush (turdus  rufus,) &c.  They
have a very bitter  taste, and a spiritous impregnation of
them, is much used as a morning bitter, and sometimes as
a remedy in intermittents, in  many parts of the  United
States. 
14
             EXPLANATION OF THE PLATE.

   (A) A view of the four folioles of the involucre.
   (B) An  expanded flower, exhibiting the  involucre, in
the centre of which are placed the flowers.
   (C) A single blossom exhibiting the calyx, petals, and
four stamens.
   (D) The four-toothed calyx, and the pistil.
   fJE) The ripe drupes, or berries.
    The  Cornus  Sericea, or  American Red-rod cornel,
agrees in its generic character, with the Cornus Florida.
It grows in a moist soil, commonly by the sides of creeks
and rivers, and seldom attains the height of more than ten
or twelve feet.  In general, a considerable number of stems
arise from the same root, and are very straight.   The bark,
or rather  epidermidal covering of  the  young  shoots, is
very smooth, shining,  and of a rich dark red colour.  This
circumstance added to the manner of growth of the stems,
has procured to this species, the improper name of the Red
Willow, by which name it is known  in many parts  of the
United States.  In Virginia it is called the Swamp Dog-
wood,  and Rose Willow.   The branches are placed oppo-
site, as are also the leaves, which a good deal resemble
those of the Cornus Florida.   Their under surface has a
somewhat silken appearance, on which account, Linnaeus
gave to this species the name of Cornus  Sericea.   The
flowers are produced  in  clusters or cymes, of  a whitish
colour, and  commonly make their appearance in June or
July; they are succeeded by succulent drupes, or berries, 
15
which are of a blue colour, inclining to green when ripe.
They are eaten by different species of birds.
    I am informed by Professor Barton, that the Indians of
North-Carolina used to scrape the inner bark of this tree
and smoke it in their pipes, when their tobacco was scarce;
and they would frequently mix  the  bark of it along with*
their tobacco to smoke.  This habit would seem to imply
something narcotic.
    For an excellent figure of the  Cornus Sericea,  I may
refer the reader to the late Mr.  L'Heritier's valuable Mo-
nographia  on the genus Cornus.
    On the uses of the Corni in the arts, much might be said;
but I shall merely enumerate a few of the most important
purposes to which they may be applied.
    The fine texture, hardness, whiteness, and durability of
the wood of the Cornus Florida, renders it an important arti-
cle to  the cabinet-makers and joiners, in inlaying and
ornamenting their  various works.   To the mechanic in
general, in making the most durable handles to their instru-
ments,  their guages, squares, and plane stocks, &c. for all
of which purposes, it is but little inferior to the English Box-
wood.   To the dentist it  is no little  acquisition, being the
only kind of wood which will answer the purpose of pluging
in transplanted teeth.
    The straight slender red sprouts of the Cornus Sericea,
are often employed for making baskets.
    The bark of these two species of Cornus are very similar
in those properties, which interest the mechanic. The more
abundant bark of the Cornus Florida will, therefore, recom-
mend itself in making ink, tanning, dyeing, galling, &c.
For the quantity of gallic acid in the  bark of the Dogwood,
intitles the latter to rival the oak and the galls in the above
processes.
    For the purpose of encouraging the use of our own indi-
genous vegetables, as well as lessening the necessity of im- 
16
porting the galls, I have here given the result of several
experiments on the subject of making ink.  By mixing
           i oz. Pulv. Cort. Cor. Flor.
           2 dr. Sulph. Iron.
           2 sc. Gum. Arab.
          16 oz. Aqua. Font.
an  excellent  black  thin  ink was  made,  fit for immediate
use—and with  which  the whole MS.  of this  disserta-
tion has been written.   I must here observe that it is not
necessary to be particular in choosing the particular parts or
size of the part of the tree, in procuring the bark for this or
medical purposes.  I attended to this in the early part of my
experiments, but I found the difference  in virtue between
the bark of the  root, body, or branches of a moderate size
not to be worthy of notice.


                    QUALITATE.

    THE majority of practitioners of the present time, pay
so little attention to  this mode of investigating the medical
qualities of plants,  that I shall not be very minute on this
part of my subject, which, according to the design and order
above given, first presents together the Cornus Florida and
Sericea, and the Cinchona* Officinalis  for similar investi-
gation.
    Plants, like animals,have a considerable analogy in their
structure.—Hence what is said on the  bark of the one will
apply, with but little exception, to the  other two. A hori-
zontal section of a branch of the Cornus Florida, exhibits an
external thick covering or bark, which is perceptibly divided
into three distinct rings or layers, the outermost of which is

   * Fori deemed it unnecessary to say any  thing on the Botanical history
of the Cinchona.   It has been too long a favourite article in the Materia
Medica, to require, now, an historical account. 
iy
called Epidermrs,*—-the middlemost Parenchyma, and the
 innermost  is called Cortical, this latter is the part which
 is  to occupy  our  attention in the  present  and  subse-
 quent divisions of this dissertation.   The colour  of this
 Cortical part is in the Florida, yellowish, in the Sericea grey-
 ish, and in  the  Cinchona red.  Its taste is in all three of
 these vegetables nearly similar, though somewhat more bit-
 ter and astringent in the corni than the Bark: the  former
 when retained  in the mouth sometime, only impart to the
 tongue these two  tastes, along with  a pleasant warmth;
 whereas when the latter is retained  the same length of time,
 along with this bitterness  and astringency,  it imparts  an
 indescribable taste, which  will be easily recognized  by
 every one who  has taken the bark.

                   EXPERIMENTA,
          INCLUDING THEIR  CHEMICAL ANALYSIS.

       SO  important is analysis to chemistry, that many,
 learned in  that science, have honoured it by calling chemis-
 try the science of analysis:  and certainly no researches, in
 which man has been engaged, have unfolded the powers of
 his mind,  in  a more  ample manner, than this  part  of
 chemistry.  In its history  we perceive  the gradual deve-
 lopement of his intellect, in shaking off the trammels of
 Egyptian priests, and emerging from the veil of alchemical
 hieroglyphics.
     But in no view do we behold him more nobly engaged,
 than in tracing, link after link, that elective attraction, which
 binds together the particles  of matter,  and  which, it would
 seem, were intended  by Nature  to  conceal  them under
 eternal darkness.
   * Grew and Malpighi, were the first who minutely examined the struc-
ture of vegetables, and gave names to the different parts. The latter  was
a celebrated anatomist and  physiologist.  Hence the above anatomical
names.
                            C 
18
    But the destructive flame, while it conceals  its own
simplicity, developes the  composition of those bodies on.
which it  operates.  By our  acquaintance with this pro-
methean torch, we approximate our works to those of na-
ture, since we do not the less immitate her,  by commencing
where she terminates; and though we cannot equal her, in
composition, we certainly rival her in resolving bodies into
their primordial simplicity.   When has a natural  analysis
taken  place, without  destroying itself in obedience to
synthetic  laws ?
    But the  chemist, when he has broken the vinculum of
union  in  bodies,  collects the separated particles, and re-
serves them for future investigation.  This is the business
of analysis. In the progress of this operation, two stages may
be marked;  first, that which resolves compounds into their
proximate or  secondary  principles,* such as  gums, re-
sins, &c.  and secondly, that which decomposes these again
into their  ultimate particles, as carbon, hydrogen, &c.
    Since  my  object is to  treat the  Corni as articles of the
Materia  Medica,  I  shall only prosecute their  analysis
to the first stage; this being the only one which enlightens the
subject in  such a view:  for though plants by their diversity in
size, colour, texture, and form display, to our  observation,
characters apparently the most dissimilar, yet they afford, by
their ultimate  analysis, results so  simple  and  similar to
each other, as not to be the objects of the Materia Medica.
    In prosecuting this analysis, I have laboured to be con-
cise.  To have detailed separately the various experiments,
to which each individual article was subjected, would have
extended this dissertation far beyond the ordinary limits of
an  inaugural thesis.   I have, therefore, arranged such ex-
periments, as admitted, into a condensed tabulated form.
    I have likewise laboured to be accurate.  Many experi-
ments Avere  performed in such manner, that the succeeding
either confirmed or disproved the accuracy of the  preced-
                       • Fourcroy. 
19
ing: thus, in ascertaining the solvent power of different
menstrua, by weighing  the  menstruum before and  after
maceration on the article, the difference in weight shewed
its  solvent power; this was again confirmed by the residue,
after evaporation, agreeing with the above difference.
    The first experiment which I made, was  distillation.
Equal quantities, that is one ounce of the pulverised bark
of the root of the Cornus Florida and Sericea, and of the
red Peruvian Bark,  were macerated in six ounces of water,
in retorts, during six hours.   Receivers were then luted to
the retorts, and heat  gradually applied,  and continued
until near half of the fluids had come over; the receivers
were then changed, and empty ones  adapted as before;
the heat was then increased to the intensity which Argand's
lamp would afford, and continued until the powders appear-
ed, in the retorts, like dried cakes.
    The products of the first distillation of the Corni were
transparent  whitish fluids,  possessing  a slight aromatic
odour, resembling  new whisky, without any perceptible
taste.  They did not produce any change with the following
re-agents, employed with the products of the second distilla-
tion.   Knowing that etherial oil, which is the base of vege-
table aroma,  appears  under  different  forms,  I did not
conclude  against its presence  in the Corni,  because it did
not  swim on the surface of the  distilled liquor.  The
whiteness of the fluid indicated the presence of something
which I concluded  to be  essential  oil,  having  its specific
gravity,  equal to that of  the fluid,  and might, therefore,
remain in any part of the fluid, without rising or sinking.
    The fluid, distilled from the Peruvian Bark, differed
from the  above in  no  respect, but in possessing a flavour
not aromatic, but peculiar to the Bark.  The fluid was clear
and transparent.
    The fluids, furnished by the last distillation* were  more
disagreeable  in smell, with a taste somewhat acerb. Those
from the Corni acquired a lemon  colour;  that from  the
Peruvian Bark was tinged with red. 
20
    The following is a synopsis of the changes which to<?k
 place upon mixing the fluid, distilled from
    With litmus paper*  Oxy-sulphate. Ace. Lead.   Carb. Alumen.
    CCorn. Flor. Red.    Black.    Precipitate.  Effervescence.
the < Corn. Seri. Red.    Black.    Precipitate.  Effervescence.
    CCortPeru.  Red.    Brown.   Precipitate.  Slight Effervescence.
   This experiment sufficiently proves that the virtues of the
Corni and Peruvian Bark are for the most part fixed, and that
each contains the gallic acid, though it is in greater quantity
in  the Corni than  in the Bark,  as  is manifest from the
difference in the  colour, produced by their mixture with
the oxy-sulphate.   The gallic acid likewise comes over in
distillation  in an uncombined state, as  appeared evident
upon applying a piece of litmus paper which had been dipped
into the distilled fluid, with a similar piece taken out of a
saturated solution of the  carbonate of potash, a perceptible
effervescence took place.
    This experiment likewise  adds some weight to those of
Dr. Skeete, who with a boldness paramount to his ingenuity,
has denied to the Peruvian Bark an aromatic quality, which
had been conferred upon it for near  a century, and which
had been the foundation for many of its praises. Attentive
to this circumstance, I conducted the distillation with  a
gradually increasing heat,  furnished by Argand's  lamp,
which enabled me  to regulate it in the manner I judged
most  favourable  for the  production  of essential oil, but,
upon examination, I could not detect the least quantity.
    Discouraged  at  the result of this experiment, and re-
collecting the success of the ancient chemists, many of
whom laboured thirty years  in the  distillation of dried
vegetables,  without obtaining a different result, I did  not
choose to prosecute  the distillation farther,  but preferred
following the moderns in the employment of menstrua. For
the improvement of this kind of Analysis, the Materia
Medica  is greatly indebted to the labours of Bouldoc and
* Of the shops. 
21
Fourcroy, since  it is this  kind wfiich has enriched it with
some of its most important articles, as gums, resins, ex-
tracts, &c.  The following table  exhibits,  in a synoptical
view,  the solvent power of water, under different modes
of treatment.  There is but little requisite to be said in
explanation of it, since the slightest attention will render it
intelligible. But it may here be observed, that the chalybeate
solution, mentioned in the last column, was the oxy-sulphate
of iron, dissolved in water, in the proportion of one dram
of the former to four ounces of the  latter, which is the
proportion  to  be  recollected, whenever this solution  is
mentioned, and the proportions of the preparations tested,
and  the test is half an ounce of the former to half a dram
of the latter. 
TAnLE 1st. SHEWING THE SOLVENT POWER.OF THE SAME MENSTRUUM UNDER DIFFERENT MODES OF PREPARATION.
_-------		Proportion (f		7'ime of			Weight of			Quantity	
		Solvend and		prepara-	Sei&ib	'e Qualities.	Menstruum			per ounce,	Colour Hvith
ARTICLES EXPERIMENTED WITH.		Solvent in		tion in			P	er oz. in		taken up	Chalybeate.
	erf in all the Experi-	dr.	OZ.	Hours.	Colour.	Taste.	dr	sc.	grs.	in grains.	
Water emph)											
	ments.						7	2	11		
«« f Pulv. Cort.	Rad. Corn. Flor.	4	6		lignt red	Bitter acerb.	8	0	7	16	dark black
r» a Pulv. Cort.	Arb. Corn. Flor.	4	6		light red	bitter acerb.	8	0	H	I5i	black
fc|j:<! Pulv. Cort.	Rad. Corn. Seri.	4	6		dark red	bitter	8	0	5	14	dark black
g 8 | Pulv. Cort. Q l^Pulv. Colt.	Arb. Corn. Seri.	4	6		dark red	. and acerb.	8	0	5	14	black
	Peru. Rub.	4	6		red	bitter do.	8	0	°i	H	dark
^ ("Pulv. Cort.	Rad. Corn. Flor.		5	24	red	bitter	8	0	H	lH	dark black
ci ° Pulv. Cort.	Arb. Com. Flor.	3	5	24	red	and acerb.	8	0	i	10	ditto
fc .2 J§ <^ Pulv. Cort.	Rad. Corn. Seri.	3	5	24	dark red	bitter	8	0	2	n	dark black
SI4-] Pulv. Cort.	Arbo. Corn. Seri.	3	5	24	dark red	and acerb.	8	0	2	ii	ditto
►h [_Pulv. Cort.	Peru. Rub.	3	5	24	red	ditto	7	2	16	5	black
£.8 ("Pulv. Cort.	Rad. Corn. Flor.	4	6	i 2	light red	bitter	8	0	3	12	ditto
■* |C J Pulv. Cort.	Arb. Corn. Flor.	4	6	1 2	light red	and acerb.	8	0	2'	"i	ditto
£J-C«^ Pulv. Cort.	Rad. Corn. Seri.	4	6	1 2	dark red	bitter	8	0	1	10	ditto
S S-5 | Pulv. Cort.	Arb. Corn. Seri.	4	6	1 2	dark red	and acerb.	8	0	4	10A	ditto
K •*» [_PuIv. Cort.	Peru. Rub.	4	6	I 2	light red	ditto	7	2	19	8	dark
j, u fPulv. Cort.	Rad. Corn. Flor.	3	5	1 2	light red	bitter	8	0	6	15	dark black
«i^ Pulv. Cort.	Arbo. Corn. Flor.	3	5	x	light red	and acerb.	8	0	5	14	ditto
pi-c °<i Pulv. Coit.	Rad. Corn. Seri.	3	5	1 -J	dark red	bitter	8	0	3	12	dark black
g-^S (Pulv. Cort. 3-g LPulv. Cort.	Arb. Corn. Seri.	3	5	J.	dark red	and acerb.	8	0	3	12	ditto
	Peru. Rub.	3	5	1 2	light red	ditto	7	2	181	7i	black
 
23
    Though few comments upon this table are required, it
will not be improper to point out some of the peculiarities
which prevailed in these experiments, and which could not
be noticed in the table.  The difference in all these prepara-
tions is not so great as to require describing them in separate
classes.   I  may therefore, add, that though the  taste of
the Corni is a more simple and agreeable bitter than the Pe-
ruvian Bark, it has nevertheless considerable austerity com-
bined with it; the decoctions possess most of the latter, and
the hot triturated infusions the next.  I may likewise add
that the decoctions and hot infusions were less elegant pre-
parations -, the hot menstruum held in suspension some of the
fine powder, which was not entirely deposited by cooling,
nor in passing through the filter.
    This  circumstance accounts for the generally received
opinion, that heat  increases the solvent power of water on
vegetables in general, and in so considerable a degree, upon
the Peruvian Bark in particular, that Dr.  Skeete estimated
the specific gravity of the decoction to be, to that of the infu-
sion as five to two.   In this part of the  Doctor's valuable
observations on the Bark, his usual correctness must have •
deserted  him.   The result of the  experiment in  Table,
1st. article the last,  in experiments  the  second and third,
shew their  specific gravity to be as, 1.900 to  1.000.  Nor
is this superior gravity of the decoction over the infusion
owing, as the Doctor supposed, to the superior solvent pow-
er of the hot over the cold menstruum, but to the mere
suspension of the fine powder of the Bark in the menstru-
um,  which becomes so incorporated  with the gum  and
mucilage, by the heat increasing their liquidity, and by the
agitation of boiling, that it is difficult to  separate it after-
wards.   This is rendered probable by  the after analysis of
the gum.  What could the superior darkness of the solution
of the gum obtained from the decoction, be owing to, unless
to something which was insoluble  in  water and alcohol?
Nor did  the decoction manifest stronger virtues  by  its 
u
 sensible qualities, or from the change it  produced with a
 solutionofthe oxy-sulphate,nordidthe effects producedon the
 pulse, hereafter  to  be mentioned,  manifest its superior
 power.    I shall  not dwell longer on this part of the table,
 in pointing out the peculiar advantages which each mode of
 preparation has,  but shall only  add,  that experiment the
 fifth, shews the cold triturated infusion to be equal to any,
 and it has the advantage of expedition.
    As the ascertaining the exact quantity of gum, resin, or
 extract, in any given quantity of the articles in substance,
 would be more curious than useful, and more difficult than
 either, from  the tenacity  of these substances to the vegeta-
 ble  fibre, I  have*  omitted  such  inquiry,  while  I  have
 directed  my experiments to the more useful investigation
 ©f  what part of the  vegetable  their virtue resides, and the
 proportion which these parts bear to each other, in the more
 common preparations of infusions, tinctures, &c. The utility
 of such an inquiry must  be palpable to every one who is
 acquainted with the powers which chemistry furnishes us,
 by which we  may imitate, or modify these proportions when
*hey shall be known.
    Already much has been done by the artificial combina-
 tion of bitterness and astringency. and though I have not the
 vanity to  suppose I  shall add  any thing new,  to the long
 sought for constitution of the Bark, yet my object will be
 answered in  tracing its analysis with that of the  Corni.
    Experiment, 6. The object of this experiment was, to
 ascertain the constituent  parts of the  gum like mass, furn-
 ished by the  evaporation of the decoction of the bark of the
 root of the Cornus Florida. Two drams of this gum, which
 were furnished by seven and a half ounces of the decoction,
 were macerated in successive quantities of the best alcohol,

   * For which omission, I may expect pardon, when I add, that Dr.
Percival, whose  patience  was equal to his zeal for science, acknowledged
that twenty-five coctions, and thirty macerations were insufficient to ex-
haust the virtues of the Cinchona. 
25
until the last portion ceased to be changed in colour and
taste; this, like the former portions, was separated from the
gum by the filter; after the gum had dried upon the filter,
it was collected, and weighed only half a dram.  The dried
gum was then dissolved in a small quantity of water. Its
solution was imperfect, not transparent, nor bright coloured;
it possessed no particular taste, which might not be ascribed
to its viscid consistence; and it produced no change of colour
with a solution of the oxy-sulphate of iron.   The want of
transparency led me to suppose there might be some muci-
lage in the solution; to determine which I added, in small
portions,  diluted sulphuric acid to the solution: a preci-
pitate slowly fell  to the  bottom in a coagulated  form.
When the precipitation had ceased, it was separated from
the solution by the filter, and evaporated to dryness, at the
same time with the solution.  By weighing each residium,
I found the mucilage to be  in the proportion of three to
five,  that is eighteen grains of  gum, and twelve of muci-
lage.
    I should here  observe, that upon the addition of the
acid, the solution turned dark, and that I do not ascribe the
want of transparency in the  gummy solution to the pre-
 scence of mucilage entirely;  but to the fine powder of the
medicine, which the viscidity of the fluid suspended and cor*.
cealed;—and probably the change of colour, just mentioned
was owing to the carbonation of these particles by the acid.
    The alcohol which had been employed in the early part
of this experiment, was next examined, and  found to pos-
sess an intense  bitter taste along  with considerable  astrin-
gency: it produced an intense black colour, with the oxy-
sulphate of iron.  Its colour was a beautiful dark red, not
inferior  to the tincture of kermes.   By evaporating the
alcohol, I obtained a dram  and a half of  what  ancient
chemists called saponaceous matter, but what I shall, after
the  example of Mr. Hermstadt,* to  whom I  am indebted
            * Vide Med. and Phys. Journal of Lond.
                           D 
26
 for the suggestion of many of the re-agents employed in these
 experiments, call extractive matter; which he says may be
 distinguished from  all other vegetable matter, by being-
 soluble in water and alcohol,  and not in sulphuric ether.
 But I must here observe, that this character is more exten-
 sive than Mr. Hermstadt appears to be apprized of,  for it
 equally applies to the Tannin principle.   May not Tannin
 be the extract of vegetables altered by the gallic acid?  The
 above character of extractive matter, suggested the mace-
 ration of it in ether, to ascertain whether the water, by boil-
 ing the medicines  in  substance, had taken any of their
 resin.   Accordingly two ounces of sulphuric ether was
 poured on the ninety grains  of extract, which, at the end
 of thirty-six  hours,  was separated by the  filter; and this
 was repeated as often as the last portion of ether was chang-
 ed in taste or colour, which changes indicated the presence
 of resin.   After the last filtration the extract was suffered
to dry upon the filter; when collected and weighed, it had
 lost only six grains of its former weight.
   The ether had acquired a  bitter taste, without astrin-
 gency.  It did not produce a black colour with a solution
of the oxysulphate of iron.   The evaporation of the ether
lefta brown resinous mass in the vessel, which weighed nearly
 six grains.  From the  difficulty, if not the impossibility,
 of accurately separating the tannin and the gallic acid from
 the extractive matter, at this stage of the analysis, I omitted
the attempt, and preferred considering the extractive mat-
 ter as a terniary compound, possessing a very bitter taste
 along with considerable astringency; it  produced  a black
 colour with the oxy-sulphate.
   The gum from the decoction of the bark of the root of
 the Cornus Sericea, and of the Peruvian Bark, were treated
 in a  similar manner.  Their ingredients, along with their
 proportions, may be seen in the following synopsis.
   The sensible and chemical  qualities of the decoction
 of the bark  of the trees Cornus Florida and Sericea, dif- 
TABLE II. SHEWING  THE  SOLVENT POWER OF DIFFERENT MENSTRUA
                              PER OUNCE.
ARTICLES EXPERIMENTED ON
                  SPIRIT VINI.
 FXP 7  P11^* C°rt* Rad* Corn' Flor"
  Tine  j PuIV" C°rt* Arb* Corn- F,or-
with SpiX Pulv* Cort« Rad. Corn. Seri.
 rit-Vini.   Pulv. Cort. Arb. Corn. Seri.
         iPulv. Cort. Peru. Rub.
                 PROOF SPIRIT.
f.xp. 8.  fPulv. Cort. Rad. Corn. Flor.
  Tine.    Pulv. Cort. Arb. Corn. Flor.
  with V Pulv. Cort. Rad. Corn. Seri.
  proof    Pulv# Cort# Arb# Corn> Seri>
Spirit of  , puly> Cort> peru> Rub>
EXP. 9.
 Vinous
tincture
  of
           PORT WINE.
  Pulv. Cort. Rad. Corn. Flor.
  Pulv. Cort. Arb. Corn. Flor.
■^ Pulv. Cort. Rad. Corn. Seri.
  Pulv. Cort. Arb. Corn. Seri.
 tPulv. Cort. Rub. Peru.
Proportion
of Solved
& Solvent.
 dr.  oz.
Time
  in
Days.
Sensible quality,
   Colour.
  colourless
  light red
  light red
  deep red
  deep red
  dark red

Light yellow
lemon colour
    ditto
  deep red
    ditto
  dark red

  deep red
  increased
    ditto
  dark red
    ditto
  deep red
 Weight of
Menstruum
per ounce in
dr. sc. grs.
 4
19

161
16
7  1   9
7 2   0
7  1  18
7  1  19
7  1  181
7  1  17
Quantity
taken up
 per oz.
in grains.
15
141
lH
12
20

16
16
191
il
 9
10
tr i

T3

91.    grains of gum-
8      like mass.
 
28
    This table, as well as the former,  proves the superior
 solubility of the Corni  in aqueous  and  diluted  spiritous
 liquors, while the Peruvian Bark is equal to  it in alcohol.
 The inferior solubility of the Bark in aqueous fluids can only
 be owing to its possessing resin in the greatest quantity,
 which is sparingly soluble in such fluids,  while  the Corni,
 possessing more gum and extract, are nearly  soluble alike
 m water and alcohol.  They are likewise more miscible in
 water,  than the Bark, as might be inferred from the latter
 possessing the greatest quantity of resin.   And I may
 observe that the Cornus Sericea approaches nearest to  the
 Bark, in the proportion of its constituent parts, as may be
 seen by an attentive examination of their analysis.  To add
 more on their sensible qualities, would only be a repetition
 of the sensible qualities of the Bark, which, it is presumed,
 are sufficiently known; for, as far as I can perceive, they
 are exceedingly alike.  Their colours being different shades
 of red,  and their tastes bitter and astringent.
    The tenth experiment had for its object the separating
 the extractive matter taken up by  the alcohol, from  the
 resin.   With this  intention I macerated one  dram of  the
 resinous mass of the  Cornus Florida with repeated small
 quantities of sulphuric ether:  the solution was very imper-
 fect.  The first and second  portions of  ether acquired a
 dark colour, the third was so little altered in colour, that I
judged  it had taken up all the resin.  This portion of ether,
 like the other two, was separated from the insoluble mass
 by the filter, and mixed with them.  The ether was now of
 a bitter  taste, without much astringency; it did not strike a
 black colour with the oxy-sulphate: upon evaporation it af-
 forded forty-five grains of resin, of a yellowish colour. The
 extract  now collected from the filter was  of a dark colour,
 with  considerable bitterness and astringency,  produced an
 intense  black colour with the oxy-sulphate, and weighed
 fifteen grains.   It is to be recollected that the small  quan-
 tity of the medicine, employed in this experiment,  to be 
29
tested, was equal  in  all  these  articles,  and for  which
allowance has been made.  The following synopsis exhibits
that
   ,-.      r  ,  , ,.  .*    e ,-,    Resin. Extract.-.    --
    4 oz. or alcoholic tmc.  of Cor.                |    fSrs*
      Flor. there is in  grains        45      15   j  to [ 60
T J 41 oz. of alcoholic tine, of Cornus                L',2 J
   |  Sericea, there is in grains       471    121  j  5 J 60
    4 oz. of alcoholic tine, of red Pe-                j    j
      ruvian Bark, there is in grains   51       9  J    ^60
    I am here to observe that the extract is to be considered
 as a compound of extract,  tannin, gum, perhaps a little
 mucilage,  and the gallic acid ; for  alcohol has the property
 of taking  up  all these in  a small quantity from vegetable
 matter.
    A summary recapitulation of these experiments shew
 that the  Cornus Florida and Sericea, and the Peruvian Bark
 possess  the same ingredients, that is  gum, mucilage, and
 extract,  which  last contains the  tannin  and  gallic acid,
 though in  different proportions.   The  Florida possesses
 most of the gum, mucilage,  and extract;  the Sericea the
 next, which appears  to be  an intermediate between  the
 Florida and Peruvian Bark; while the latter possesses most
 of the resin.  Their virtues appear equally similar in their
 residence.  The extract and resin possess all  their active
 virtues.  The extract appears to possess all their  tonic power.
 The resin, when perfectly separated from the extract, ap-
 pears to  be purely stimulant; and probably the tonic power
 of  the extract is increased, when combined with a portion
 of the resin, as in the  spiritous tincture.

 THEIR RELATIVE POWER OF RESISTING THE PUTREFACTIVE
                     FERMENTATION.

    BY this term, which was first  introduced  into chemis-
 try in  the sixteenth  century, by Van Helmont, is under-
 stood "  that spontaneous decomposition which takes place
 in vegetable and animal substances, after death."  Although 
30
 the surprising phoenomena which attend this natural analy-
 sis of bodies, were not unnoticed by the antients, yet they
 remained for many years in the greatest obscurity.  Nor
 was it until the close of the  eighteenth century, that this
 cloud began  to be dispelled, by the illustrious but unfortu-
 nate  chemist,  whose discoveries have immortalized his
 name by giving a new a?ra to chemistry.   Lavoisier, the
 ornament of philosophy, and the boast of chemistry, taught
 us the nature of those gasses which have a principal share
 in this process.  It was Lavoisier, for whose untimely fate,
 philosophy mourned,  and chemistry  acknowledged  her
 loss,  that gave origin to the present theory of chemistry,
 which now adorns the ninteenth century.  But unfortunate
 for this subject, the rapid improvements which distinguish
 this  age have not been equally extended to it.   For not-
 withstanding the labours of a Macbride, a Percival and a
 Priestly, the complicated changes which take place in putre-
 faction, are still inveloped in darkness and uncertainty.
   Equally uncertain is the modus operandi of certain me-
 dicines in preventing or checking these changes, when they
 have  commenced.   I feel the less  diffidence in declaring
 their  manner of action to be the object of my present inqui-
ry, since I shall not wander in the maze of theory,  nor go
 a step beyond the broad basis of experiment.  And  as
 " every theory  founded on experiment and not assumed,
 is always good  for as much as it will explain," I shall con-
 fine my observations to astringent vegetable substances.
   Since the time of  Anaximenes, with whom Nature's
 great law* was  uniformity, philosophers and chemists have
united in acknowledging the homogeniousness  of Nature's
works: from this  universal principle sprung the co-exten-
 sive law of chemistry, that every body has  either an effi-
 cient  or predisposing affinity for every other. These affini-
 ties are changeable into each other, and upon their mutual
* Enfield's History of Philosophy. 
31
conversion,  which, however,  is modified or prevented by
every possible variety of circumstances, depends those
secret and wonderful operations of nature. Thus the sugar
in the matured grapes, possesses, within their integuments,
a predisposing affinity for oxygen,  and no sooner do the
circumstances of its development into a fluid, the access of
air, and increase of heat, take place, than this predisposition
is changed into efficiency, which constitutes the vinous fer-
mentation, whose degree and continuance  is modified by
the paucity of sugar, or deficiency of heat. Hence the vast
variety of alcoholic products.   Or it is changed by the too
long continuance of these circumstances, or their existing
in too favourable a degree, which facilitates the too speedy
union of the oxygen  with the  carbon of the sugar,  and
thereby reduces it to mucilage, by the decarbonation of the
sugar in the form of carbonic acid. Hence the acetous fer-
mentation.   Or this conversion of affinities may be again
changed by the too great heat, too free access of air, or
too great fluidity, which while it evolves the gluten of the
vegetable, conducts to  the putrefactive fermentation, which
ends  in the volatilization of the ingredients.  Or, lastly,
this change  may be prevented  by destroying the efficient
affinity of the sugar, mucilage, or gluten for oxygen. Thus
has Nature,  in  stamping similarity on her  productions,
planted within them the germ of their  destruction;  thus
does she make affinity the principle of  synthesis and the
cause too of analysis; and thus does she accomplish the
perpetual circle of compositions and decompositions, which
demonstrates her fecundity, while it anounces equal gran-
deur and  simplicity in her operations.   Hence the differ-
ence between Nature and Art.  Nature is rich in poverty,
Art is poor in riches. Nature has few materials*,her works
are innumerable: Art has many,her works are  few.
   Such are the principles of pneumatic chemistry, which
teach  us,  we have only to substitute  gelatin for  gluten,
* Or elements- 
32
to make the above illustration apply to animal putrefac-
tion.
   The illustration already given shews us, too, the foun-
dation for two kinds of antiseptics, which may  be called
mechanical  and chemical.  The enveloping the  gelatin in
a body impermeable to air, as resin, or the condensing the
particles of the gelatin within the sphere of a too strong at-
traction, by boiling and drying, as in making portable soup,
belong to the first, while those bodies, which present to the
gelatin an affinity superior to that for oxygen, belong to the
latter; such are astringent vegetable substances.
   The first experiment which  was made on this class of
vegetables, was with a view to ascertain the comparative
antiseptic power of the Corni and Peruvian  Bark.   Ac-
cordingly four drams  by weight of  fresh veal,  were im-
mersed in equal quantities, that is two ounces of the fil-
tered infusion of the Cornus Florida and Sericea, and the
Peruvian Bark, in separate tumbler glasses.   The immer-
sion of the veal soon occasioned a precipitate, of a greyish
colour, in the infusion from the Corni,  and reddish in that
from the Peruvian  Bark,  and also of unequal quantities,
being greater in the Florida and next in the Sericea. The
result of this experiment (see Table  3. Exp. 11.) shewing
considerable proportion between the antiseptic power of the
articles,  and the  precipitates, induced  me to ascribe the
antiseptic power,  to the precipitate; which, upon examina-
tion, was found to be the tannin principle; a substance to
which our attention was first called by Sequin,  and after-
wards investigated by Proust.
   The  changes  which  the muscular fibre  underwent,
greatly confirmed this opinion; its juices were soon decom-
posed, the red blood lost its colour, and the fibres appeared
corrugated and condensed, though these changes were less
in the infusion from the Peruvian Bark.  These changes
rendered it very probable  that the gelatin of the fibre, and
of the blood united to the tannin, and formed  a compound 
33
capable of resisting putrefaction in proportion to the quan-
tity of the tannin  present: for on the sixth day, at which
time the veal in the  infusion from the Peruvian Bark was
offensive, a portion of veal was taken out of the infusions
from the Cornus Florida and Sericea, which was perfectly
sweet; when dry I found it pulverable between the fingers,
but could not trace the fibrous  texture:  so intimate was
the union with the tannin.   For though there was a differ-
ence in this respect, between the muscle and tanned leather,
I nevertheless ascribed the change to the tanning process,
judging the difference in appearance and  qualities, to be
owing to the difference in texture.
    To prove this more decisively,  I precipitated  the tan-
nin from fresh infusions of the medicines, by a saturated
solution of glue.   The liquor was then separated from the
precipitate, formed in this manner, by the filter, and four
drams of fresh veal were added, as in the former experi-
ment, but with a very  different result.  Its antiseptic
power was destroyed.  See Table 3. Exp. 12.
    It is unnecessary to dwell longer on this part of the ex-
periment, since the following table shews  the experiments
which were made, and the changes which took place.
    For the better  understanding the table, it is to be recol-
lected that all the infusions of the different medicines were
made under similar circumstances, and in similar propor-
tions.   Thus the simple infusion employed in experiments
 11. 12. 13. 14. were made with two drams of the powder,
and four ounces of water, macerated twenty-four hours, and
then filtered.   The  compound infusions were made by
triturating two drams of the powder, and one dram of the
calcareous  earth,  with six ounces of water;  which, after
 standing the same length of time, were filtered.
E 
                                                          TABLE III.


SHEWING THE ANTISEPTIC POWER OF THE  INFUSIONS OF DIFFERENT MEDICINES, IN THE TEMPERATURE OF ABOUT
                                         72° OF FAHRENHEICHT'S THERMOMETER.
§1
W73
Oh
Changes ivhich took place (the figures stand for days.)
MEDICINES.
("Simp, aqua.
;  Cort. Rad. Corn. Flor.
  Cort. Arb. Corn. Flor.

  Cort. Rad. Corn. Ser.
  Cort. Arb. Corn. Ser.

  Cort. Peru. Rub.

  Cort. Qiierci. Rub.

  Rad. Columb.

  Pulv. Gallae.
Proportion of
 Infus. Veal.
        dr.
oz.
 2
 2
 2
 2
 2
1 Pale, 2 texture diminished and greenish, 4 putrid.
The relative
 quantity of
  Tannin.
    A
r.v       ■,, Time it re-
Chanee with        ,
„ „.*>   .,    mained
Gallic acid.
 C 1 Copious, precipitate, 6 sweet, fibre condensed, 15 inf. acid, 7
 \  16 mouldy on the surface, taken out and dried, sweet.    5
 CI Copious precipitate, 6 sweet, fibre condensed, grey colour, "p
'<  14 acid and mould infusion, and nearly evaporated, taken >
 C.  out, on 15.                                            j
 C 1 Small precipitate, 4 fibre lax and pale,  6 greenish, 8 pene-7
'\  trating smell.                                         3
 CI Copious precipitate, 10 sweet, 15 solid and firm,  18 infu-7
'\  sion mouldy.                                          3
\ 1 No precipitate, 2 pale and soft, 4 offensive.
 C1 Copious precipitate, 4 condensed, 8 sweet, 10 mould infu-
 \  sion, 18 acid.
10
     B
pale brow
-}
ditto
ditto
sweet.
  C.
  26
26
14
15	ditto J	30
0	ditto	7
13	Brown.	\ 30
Changes which took place when the tannin was precipitated.
fcort. Rad. Corn. Flor   2     4 $l No PreciPitate> nor corrugation of  fibre, pale, 3 green,
!                                \   5 putrid.
X  s    ■
w in    LCort. Peru. Rub.
Cort. Rad. Corn. Ser.
      . f 1 Ditto pale and relaxed, 3 greenish, 4 unpleasant smell,
z    4£   5 putrid.
2    4   1 Ditto, 3 greenish colour, soft, 4 unpleasant, 5 putrid. 
TABLE III. &c—CONTINUED.
              MEDICINES.

S.S'o  f Cort. Rad. Corn.  Flor.

jj §".2 i Cort. Rad. Corn.  Ser.
W</3
™ c«tt
'"J* L Cort. Rub. Peru.
     Changes which took place upon mixing the Inf. with Putrid Veal.
Inf. Put.
 g     . C1  Fermentation suddenly  checked,  4 sweet, 6  hardened,
 **    *i   10 acid.
4  1 Ceased disengaging air, 2 hardened, 6 sweet, 10 acid smell.
4  1 Suspended, 2 colour pale, 4 discharges air, 6 offensive.
Cort. Rad. Corn. Flor.
Cort. Rad. Corn. Ser.
Cort. Peru. Rub.
Inf. Mass.
 oz.   oz.
 2    2
Changes upon mixture with fermenting mass.
1 Fermentation checked, 4 dark coloured, 6 acetous smell.
1 Checked the disengagement of air, 6 acetous smell.
1 Moderated the fermentation, 4 acid to taste and litmus.
                                                                             ABC         D
               Infus. Veal.                                               Quantity Change with acid. Sensible quali-
                oz.  dr.                                               taken up.  Oxalic.   Gallic.     ty, taste.
Rad. Corn. Flor. 2    4flNo precipitate, 3 fibre lax, 4 bluish, 5 putrid.      19    7nrecini-  black7 Nauseous with-
Rad. Corn. Ser. 2    4< 1 Ditto slight change in colour, 5 putrid.           18 1-2 >\ t  V   Mack V   out  Astrin-
Rub. Peru.      2    4(1    Ditto    muscle redish, 4 soft and offensive.    10    J         blackj   gency.
Rad. Corn. Flor.
Rad. Corn. Ser.
Rub. Peru.
■ Nearly the same changes took place in this and the
   17th Exp. as in the 15th, all putrid in'5 1-2.
20
18 1-2
11
ditto    ditto
ditto

* E
'Cort,
 Cort,
 Cort
Rad. Corn. Flor. 2
Rad. Corn. Ser.  2
Rub. Peru.      2
ditto
19
18
10
ditto    ditto
ditto 
36
                       COMMENTS
 QN THE CLASSES OF EXPERIMENTS CONTAINED IN THE PRE-
                     CEDING TABLE.
    Strongly impressed with the justness of the princi-
 ple, which the great Newton  laid down on experimen-
 tal evidence, which  is, that " though the  arguing from
 experiments and observations, by induction,  be no demon-
 stration of general conclusions,  yet it  is the best mode of
 arguing which the nature of things admit  of;  and may
 be looked upon as so much the stronger, by how much  the
 induction is the more general." I have, to profit by the autho-
 rity of so great a philosopher, extended my experiments to
 several articles which were not the objects of my disserta-
 tion ; the plain induction from all of which, is, that the tannin
 principle of astringent vegetables, which is thrown down
 by the gelatin of the flesh, is the antiseptic principle; and
 that it acts by chemically uniting with the gelatin, and there-
 by destroying the efficient affinity of the latter for oxygen,
which is the septic principle.   The  changes which the
 muscle underwent in the infusions, as far as  they could be
 expressed in the table, agree with the quantity of tannin
 present in those infusions, as expressed under A. Experi-
 ment 11.   The relative quantity of tannin,  expressed in
 this column, was ascertained by adding equal quantities of a
 saturated solution of gelatin to equal quantities of the dif-
 ferent infusions concentrated by  partial evaporation, the
 quantity of precipitate showed the  relative quantity  of
tannin—letter B. of the same experiment,  shews that the
gallic acid is precipitated  along with the tannin,  when
gelatin is the precipitant.  For  upon the addition of the
oxy-sulphate of iron, to the infusion out of the tumblers, a
 very slight change took place.
   C. This  shews the length of time the simple  infusions
will remain free from acidity in the common stopped phials,
the figures stand  for days.  Why those infusions which
have the greatest quantity of tannin, should remain un- 
37
  changed the longest, is difficult to account for.  Unless it
  be that the tannin principle has a stronger affinity for oxy-
  gen than the mucilage of the infusion,  upon the union of
  which with oxygen, acidity depends.  This is somewhat
  probable from the circumstance that tannin will reduce the
  oxy-sulphate of iron to the common sulphate—May not this
  be the cause of the change of colour of  the  blood and
  muscle, above-mentioned? The tannin uniting to the oxy-
  gen of the blood deprives it of that principle, to which the
  present chemico-physiologists ascribe its red colour.
     What  farther  can be  required to  prove  the above
  manner  of accounting  for the antiseptic power  of astrin-
  gent vegetables, is given in  the 12th experiment, which
  proved,  that the previous precipitation of the tannin de-
  stroys this power.
     Experiment 13th shews,  that these  medicines check
  putrefaction after  it has commenced in the same manner
  and proportion.  The 14th, shews they prevent or check the
  acetous fermentation, probably by absorbing oxygen from
  the mucilage of the fermenting mass.
     Experiments 15, 16, and  17.  B. The precipitate which
 takes place upon adding the oxalate of ammoniac to these
  compound infusions, shews that the calcareous earth is dis-
 solved in them, which,  by forming a new compound with
 the tannin, destroys* its astringency and antiseptic proper-
 ty. C. D. The results in these two columns,  agree with the
 experiments of Professor Woodhousef.   For though the
 astringency of the compound infusion was destroyed by the
 mixture with the calcareous earth, it nevertheless struck a
 black colour with the oxy-sulphate, but did not possess the
 taste of astringency, nor corrugate the flesh immersed in it.
    A. Soon after the introduction of the Peruvian Bark
 into  practice, physicians not content with its solubility in

   * Vide sixth Law of the Affinity of Composition.
   t See his observations on the combination of Acids, Bitters, and As-
tringents. 
38
 aqueous menstrua, combined many different articles with
 it, to increase its solubility, and virtue in other respects;
 among which  were magnesia, lime, &c.  These experi-
 ments prove, that whatever the combination with lime or
 magnesia, may do in other respects, its solubility cannot be
 said  to be increased, for B proves  the  superior weight of
 the infusion to be owing to the calcareous earth—D that its
 astringency is  destroyed—and the  15.  16. 17 Experi-
 ments at large, prove that its antiseptic power is also des-
 troyed.
    Experiment 18. On the  styptic power of the  Corni,
 and Peruvian Bark.  With a view to ascertain this, I cut
 out  three portions from the glutsei and vasti externi of a
 dog,  with a dull  scalpel to  imitate common  incised
 wounds, on which I sprinkled the three powders, the Flo-
 rida and Sericea soon stopped the Ha^morrhagy, the Peru-
 vian  Bark was slow in stopping  it; the blood and powder
 appeared to be chemically united, and formed a defence to
 the open tubes: the Cornus appeared not only to act upon
 the surface of  the  wound, in corrugating it, and thereby
 diminishing the  orifice  of the bleeding vessels, but the
 tannin likewise precipitated the gelatin of the blood, with
 which it formed an adhesive mass,  that remained  on the
 surface of the wound.

        EXPERIMENTS ON THE TANNIN PRINCIPLE.

   IT is not my intention to give, in this place,  a treatise
 on the art of Taning.   But as  the  Corni promise to be
 profitably subservient to this art, and as there has  lately
 appeared on this subject some ingenious speculations,jwhich,
as well from the author, as their own merit, deserve atten-
tion, I hope the following digression will not be unaccep-
table.
   Though the art of tanning is  of ancient date, yet the
tannin principle is of modern discovery, with the  particular
nature of which, we are not well acquainted; chemists, how- 
39
 ever, suppose  it to be a distinct principle in vegetables.
 The ancients were content with ascribing this property to
 such vegetables as contained a gum-resinous matter, along
 with astringency; and their choice of tanning substances was
 chiefly confined to such vegetables.   Though an established
 opinion and  long practice in any art,  only give  sanction,
 without proving the correctness of such opinions; yet I am
 convinced the choice of the ancients was very judicious.
    The ingenious Mr. Biggins, supposes the tannin prin-
 ciple is all that is necessary for this process of tanning, and
 " as the gallic acid* corrugates the  surface, and  does not
 seem to  combine with the matter of skin:" he thinks u it
 not only useless but detrimental"!"."  Induced by the novelty
 and ingenuity of this opinion, I instituted the following ex-
 periments to  see how far it would obtain in practice.   I
 obtained  some pure tannin, by partially evaporating a strong
 decoction of the Cornus Florida, and adding to it a saturated
 solution of the carbonate of potash, a  copious precipitate
 fell down, which was collected  upon the filter, afterwards
 washed in a small quantity of cold water, then dissolved in
 the like quantity of boiling water.   This was tested with
 litmus  paper to  detect the excess of alkali,—the paper be-
 ing slightly changed green.  Diluted  sulphuric acid was
 now  added until the litmus paper indicated it to be neu-
 tralized.   A  greyish  precipitate  began  again to appear,
 which increased by standing.—When it had ceased subsid-
 ing, it was again separated by the filter, and then dissolved
 in  a small quantity of cold water, to  which was added a
 small piece of fresh calf-skin,  previously  deprived of the
 hair and  small pieces  of  flesh,  by the ordinary means for
 such purposes.   It  was examined on the sixth  day, but
 there was no appearance of the action of the tannin; and the
 skin appeared as unaltered as if it had lain the same length

   * It is here to be understood that Mr. Biggins means by the gallic acid
the astringent principle.
   f Phil. Trans.— 
40
 of time in pure water; it was soft, white, and slippery be-
 tween  the  fingers, and had  undergone what  tanners call
 swelling.   Convinced that the tannin thus separated, dif-
 fered from the tannin in  the fresh decoction in no other
 respect than the deprivation of the gallic acid, I determined
 to see  what effect  another vegetable acid  would have.
 Strong acetous acid was accordingly added to it, under the
 above  circumstances.  The  changes which  took place  in
 the skin in ten days afterwards, were so similar to such  as
 appeared in a similar piece  of skin, which had been im-
 mersed in some of the decoction* from which the tannin
 had not been precipitated, and which had been employed  as
 a standard by which to  judge, of the  facility of the two
 processes,  that I could not forbear concluding, that astrin-
 gency was essential, in the process  of tanning.   I should
 here abserve that the  gallate  of tannin  (for they  unite
 together by a strong affinity), is very astringent.   Now  as
 the gallic, acid though somewhat acerb in taste, cannot, from
 its weakness in this respect, be strictly called astringent, it
 is probable that the tannin  contains some alumen, the union
 of the gallic acid with which, Dr. Woodhouse, has satisfac-
 toirly proved to be astringent: this is somewhat confirmed by
 the increased astringency of  the acetite of tannin;  for the

   * I shall here give the reason, why the  dcoction was preferred as a
 standard. From the experiments of Messrs. Davy, Proust, and Sequin, it
 appears  that heat evolves the tannin principle: their experiments were
 made chiefly upon coffee ;  they found that a strong infusion of this article
did not exhibit any marks of the tannin principle, nor of the gallic acid;
 but if it was first toasted, or a decoction made from it, the liquor thus
 prepared contained the  tannin principle, and struck a black colour with
the oxy-sulphate of iron.   Is it not probable that the heat produced this
change, by increasing the affinity of the base of the gallic acidp for oxygen,
which was furnished by the air in toasting, or the water in boiling, and thus
produced the gallic acid, which united to the extractive matter, and formed
the tannin principle. However, this may be, it is worthy the attention of
tanners,  for I am convinced from the experiments which I have  made,
that thin skins may be perfectly  tanned, in the decoction of the Corni or
oak bark in ten days. 
41
potash above employed, by saturating the gallic acid, might
have  precipitated  the aluraine along with the tannin, and
which, by uniting with a portion of the acetous acid," might
have  increased its  astringency.
    In what manner astringents act in tanning is difficult to
be explained;  but it appears probable  that they serve the
same  purpose in tanning,  which  mordents do in dying—
they fix the tannin and gelatin to the cuticular fibre.
    The success of  the acetate of  tannin  above mentioned,
gives considerable  countenance to the conjecture  already
made, that the tannin principle is the mere extract of vege-
tables altered by the gallic acid.
    Under this impression I endeavoured to immitate the
tannin  principle, by uniting the extract of common flour*
with  weak alum water,  to which mixture a  thin piece of
skin, properly prepared, was added: the changes which took
place (being perfectly similar to the tanning process), con-
vinced me that  this artificial combination  of extract  and
acid possessed the true properties of the natural tannin.
    Hence I conclude astringency is essential in  tanning.
    The present subject involves the consideration of astrin-
gency in so palpable a manner, that I cannot,  though  I
willingly  would, have passed it over in silence ;  for astrin-
gency is a problem that has never been satisfactorily solved;
nor do I  pretend to such a solution, but only claim the  pri-
vilege of opinion.
    From the experiments of authors, as well as those which
I have made upon this subject,! I am convinced  we cannot

   * In many parts of our country, the country people tan  thin leather,
Uy first immersing it in flour and water several days, and then placing the
»kin in alum water.
   f I  thought it unnecessary to introduce the experiments which  I
C«de on the astringent principle, because their results only agreed with
th* experiments of Dr.  Woodhouse, that the gallate of alumine was as-
tringent. But th«y, in MO manner, tended to shew that astringency was
                              F 
42
 limit astringency to the combination of a single acid, the
 gallic, with a calcareous base. Astringency, like bitterness,
 is the result of many biniary combinations. Its production
 depends upon  those secret changes which take place upon
 the union of bodies,  in conformity to the sixth law of the
 affinity of composition.* Limited would be the expression,
 that the sulphate of magnesia was alone the bitter principle;
 equally limited must it be, if it affirms the gallate of alu-
 mine to  be alone  the astringent  principle.   Are  not the
 sulphate, the muriate, the nitrate, and acetate of  alumine
 astringent?  And what experiments have  detected the
 presence of the gallic acid in  these salts ? or, how many
 detections would  convince us of its  existence, when we
 know that the sulphuric, muriatic, and nitric acids, convert
 the  gallic into citric,  malic,  or oxalic acids—as  little
 do we know of  the tests  for the astringent  principle.
 Doctor Woodhouse, whose ingenious labours have greatly
 enriched chemistry,  proved in  a  pamphlet,  which has
 already  been quoted,  that  the property of producing a
 black colour with the chalybeate solution was fallacious.
 Taste has been supposed the most certain criterion of its
 presence.  But so little do we know of the modus operandi
 of astringents on the organ of taste, or on the solida viva,
 that even with this we are subject to fallacy. Thus, alcohol,
 by attracting the  saliva from the surface  of the mouth,
 produces a taste similar to that of astringency.   The dry
 air, by favouring the evaporation of the saliva, produces a
 similar taste, and were it not for our senses correcting the
 deception of taste,  we should taste astringency whenever
 we walked in dry air.
   Many other articles, by stimulating the absorbent sys-
 tem, the excretories of which being more simple and facile
an undivided principle,  confined to a  single neutral salt.  But, on the
contrary, every salt, of which alumine was the base, was astringent to the
taste, and many other articles are confessedly astringent.
   * According to  which compounds possess  properties different from
their component parts. 
43
in motion than the secreting, evacuate their tubes as fast as
they are filled,  and consequently produce corrugation of
the part, by the sides of the emptied tubes approaching each
other, which disposition of parts constitutes the astringent
taste.   This opinion, that astringents act upon the solida
viva, in consequence of their stimulus, is not a novel one.
Percival and Darwin, long  since, entertained it.  What
are we then to conclude respecting astringency—Shall we,
with Dr. Moore,* deny their existence; or, shall we, with
more probability, acknowledge it the property of  many
combinations.
      EXPERIMENTS ON THE HEALTHY SYSTEM.


    THE following is a synopsis of the effects of the  dif-
ferent medicines, and their different preparations, on  the
healthy human body.  And I must  here observe, that the
greatest attention was paid to obviate those circumstances
which affect the pulse, by myself, as well as by my friendly
fellow graduates, who assisted me in these experiments ;
and whose  names I with pleasure insert  to be messrs.
Massie, Downey, Wilson, and Young, and my friend Mr.
Gregg.
    To avoid unnecessary prolixity, I have only expressed
the quantity  and kind of  medicine  taken, in  each experi-
ment, without inserting the name, time of day, &c. since
it is to be presumed that every circumstance was attended
to, which could be favourable to the success of these experi-
ments.   And to render them as satisfactory as possible, I
have noted down the state of the pulse, and the affection of the
system in general, opposite to the time when they took place.
•Vide his Materia Medica. 
44
A SYNOPSIS OF THE EXPERIMENTS ON THE PULSE.
EXPERIMENT 20.    EXPERIMENT 21.    EXPERIMENT 22.
30.g-r.Pulv.Cort.Rad.		30£	r. Pulv. Cort. Rad.
	Cor. Flor.		Cor. Seri.
Mb	i. Pulse.	Min	. Pulse.
0	62 soft, natural	0	70 naturally full
5	62 slight change	5	72 quick, soft
10	63 full, heat at	10	73 do.
15	63 stomach	15	74 slight nausfea
20	65 quick and full	20	76 full
25	66 full and strong	25	76 nausea ceased
30	68 do.	30	78 full and tense
35	69 quick, tense	35	78 do.
40	70 flushed face	40	79 do. red face
45	70 tense, heat in-	45	79 regu. hard
50	70 creased	50	78 full
55	70 do.	55	78 do.
60	70 do.	60	78 do. headach
75	68 full, regular	75	77 do. quick
85	68 do.	85	75 do.
95	65 reduced in	95	73 slight
105	63 fulness.	105	70 decrease.
 Mil
  0
  5
 10
 15
 20
 25
 30
 35
 40
 45
 50
 55
 60
 75
 85
 95
105
    Rub.
. Pulse.
 66 natural
 66 no change
 67 quicker, full-
 67 er   do.
 68 full and
 69 tense
 69  do.
 70  do.
 70 strong and
 71 regular
 71     do.
 72     do.
 72     do.
 71 slight head-
 70 full    [ach
 68 do.
"67 nearly natural
EXPERIMENT 23.
EXPERIMENT 24.
EXPERIMENT 25.
* 12 g-r. of the Resin of * 12 gr. of the Resin of * 12 g-r. Of Resin of P.
     Cor. Flor.            Cor. Seri.             Bark.
0	62 soft, natural	0	72 natural	Q	64 natural
5	62 slight disgust	5	72 small	5	64 full
10	61 nausea	10	72 do. and	10	65 and
15	61 in a slight deg.	15	73 quick, consi-	15	66 regular
20	62 quick and	20	75 derable nausea	20	68 do.
25	63 fuller	25	75 fuller	25	68 do.
30	63 quick and	30	76 full	30	68 full atid
35	66 frequent	35	71 do.	35	69 tense
40	68 do.	40	77 do.	40	69 do.
45	70 do.	45	79 do. tense	45	70 do.
50	72 do.	50	80 do.	50	71 regular
55	73 do.	55	82 tense, regular	55	72 do.
60	71 do. slight	60	83 Sc flushed face	60	72 do.
65	69 headach	65	80 heat of the skin	65	73 full, flushed
70	67 full	70	79 tense	70	73 face
75	68 irregular	75	79 do.	75	70 do.
80	65	80	77 full and softer	80	66 do.
85	63	85	75	85	65 diminished ii
95	60 small	95	72	95	65 fulness.
   * Obtained by the simple evaporation of the alcoholic tincture—for
its constituent parts vide page 29. 
45
EXPERIMENT 26.
EXPERIMENT 27.
EXPERIMENT 28.
* 12 grs. of Extract of		12	grs. of Extract ol	r 12	grs. Extract of. P.
	Corn. Flor.		Cor. Ser.		Bark
M.	P.	M.	P.	M.	P.
0	68 natural and	0	76 natural	0	66 natural
5	68 soft, full	5	76 soft and full	5	60 full and
10	59 quick and	10	77 quicker	10	67 strong
15	70 full	15	78 anxiety,	15	68 quick
20	70 do.	20	78 full and	20	69 do.
25	72 do. agreeable	2S	7§ regular	25	69 do.
30	73 heat, tense	30	80 tense, flushed	30	69 do.
35	73 and regular	35	81 face	35	70 full and
40	74 do.	40	81 do.	40	70 tense
45	76 do.	45	82 do.	45	72 do.
50	77 fuller, tense	50	82 do.	50	72 do.
55	77 do. flushed	55	80 do.	55	72 do.
60	77 do. face	60	79 diminished in	60	71 full and tense
65	77 do.	65	79 hardness	65	70 do.
75	76 hard and tense	75	78	75	68 diminished in
95	69 stro. than nat.	95	77 soft and full	95	67 strength
EXPERIMENT 29.		EXPERIMENT 30.		EXPERIMENT 31.	
f 12 grs. of Gum of		12 grs. of Gum of Cor.		12,	grs. of Gum of P.
	Cor. Flor.		Flor.		Bark.
0	62 natural	0	64. natural	0	72 natural
5	62 slight change	5	65 full and	5	72 no change
10	63 in fulness	10	65 regular	10	73 fuller
15	65 full and quick	15	67 quicker	15	75 do. and
20	66 do.	20	67 and fuller	20	75 quicker
25	67 do.	25	68 do.	25	77 tense
30	70 fuller and	30	71 tense and	30	78 do.
35	70 regular	35	71 strong	35	80 do.
40	70 do.	40	72 do.	40	81 fuller and
45	71 moderately	45	73 do.	45	82 stronger
50	70 tense	50	71 slight change	50	82 do.
55	70 do.	55	70 full	55	82 do.
60	69 do.	60	69 do.	60	80 quick and full
65	69 do.	65	68 do.	65	79 ditto
70	68 soft but full	70	68 quicker than	70	76 ditto
75	64	75	67 natural.	75	75 above natural
EXPERIMENT 32.		EXPERIMENT 33.		EXPERIMENT 34.	
2 02	;. of Decoction of	2 02	:. of Decoction of	2 oz. of Decoction of	
1	Cor. Flor. R.		Cor. Ser. R.		P. Bark.
0	66 natural	0	68 natural and	0	62 natural
5	67 increase in	5	68 quick	5	62 soft
10	68 strength and	10	69 fuller	10	63 do.
15	68 fulness	15	70 do.	15	65 quicker
20	70 do.	20	71 do. quicker	20	65 with fulness
25	72 do.	25	71 do.	25	67 do.
30	72 do.	30	73 do.	30	68 do.
40	77 tense and	40	74 do.	40	69 considerable
50	80 strong	50	74 flushing of	50	71 tension
   * See Chemical Analysis, page 29.
f By evaporating the aqueous solution—For-rts component parte, see p .17. 
46
M.  P.              M.  P.               M.  P.
60  80 bounding      60  76 the face       60  72 do.
70  78 slight pain in   70  80 full and       70  73 do.
75  7-7 the head      75  79 strong        75  71 tense with
SO  74 and flushing of  80  76 slight affection  80  77 flushing of the
90  73 the face       90  73 of the head    90  69 face
100 67. quick and soft  100 70. quick pulse.  100  66 full and quick
EXPERIMENT 35.
EXPERIMENT 36.
EXPERIMENT 37.
2 oz. of Infusion of Cor.  2 oz. of Infusion of   2 oz. of Infusion of P.
     Flor. R.            Cor. Seri.              Bark.
0	72. natural	0	76 natural	0	64 natural
5	73 quicker	5	76 slight change	5	64 no change
10	74 do.	10	79 in quickness	10	66 quicker
15	74 do.	15	80 fuller	15	68 do.
20	75 fuller	20	81 quick and full	20	69 fuller
25	76 do.	25	82 do.	25	70 do.
30	78 full and	30	84 do.	30	72 tension
40	79 tense	40	84 tense	40	73 increased
50	81 do.	50	85 do.	50	74 do.
60	84 do.	60	87 do.	60	76 full and
TO	84 strong	70	85 do.	70	76 tense
75	83 do.	75	84 do.	75	76 do.
80	81 do.	80	82 heat of the skin	80	74 do.
85	79 flushing of	85	79	85	74 full
90	78 the face	90	79 quicker	90	73 do.
100	75 above natural.	100	77	100	66 above nat,
    I have but little to add on these experiments.   From
the difficulty of performing them, from the long and constant
attention they require, and the difficulty of avoiding every
circumstance, which though insignificant in itself often affects
the pulse, in a considerable degree, it is not pretended, but
some slight inaccuracy may have been noted down :  but it
is hoped they will shew the resemblance between the three
medicines.   They likewise will shew the greater  solubility
and quicker action of the Cornus Florida.  The Sericea ap-
pears to be next. This agrees with their chemical Analysis.
Their regularity, and durability of action is likewise ap-
parent, for in no one of them did the pulse return exactly
to its natural state, but was often fuller and stronger,  and
always quicker. 
47
                  EXPERIENTIA.

   The little opportunity of applying a new medicine to
practice, by the student of medicine, must  be known to
every one.  It will not, on that account be expected, that
many experiments on  the  diseased subject,  will be re-
lated.   However,  from the kindness of Dr.  Church, to
whose friendship  and attention I am greatly indebted, I
shall relate the success of an experiment with the Cornus
Sericea in  the  case of an intermittent fever which  came
under the doctor's direction.
   April  13th, 1803.  W. F. aged 34,  was taken with a
chill  about 10 o'clock, A. M. which continued 4 hours,
and was succeeded by a fever which lasted 10 hours,  it
went off in the ordinary manner by a copious perspiration.
   14th, Free from fever but debilitated.
   15 th, A similar paroxysm as on the 13th.
   16th, As on the 14th.   He now commenced with the
arsenical solution of Fowler, in the dose of ten drops  three
times aday.
   17th. Had another severe paroxysm.   The drops were
now omitted and blisters applied to his wrists.
   18th. He  had  given him six papers  of the  Cornus
Sericea, containing a half dram  each,  to be taken  three
times in the day.
   19th.  Free from  fever.  His  intermittent has not re-
turned, May 10.
   The following is a case  afforded me by my friend and
fellow graduate Mr. Hutchison, in his own words.
   On  the 25th.  of April 1803,  I was desired to visit
Samuel Anderson, aged 30, with an intermittent fever.  I
found his  pulse active, tongue furred, and his skin warm,
he complained of pain in his head and back, he informed
me he had had two paroxysms previous to my visit. 
48
    Four grains of tartar emetic were given him, which pro-
 duced a copious vomiting.   On the morning of the 26th I
 found him free from fever, and ordered 30 grains of Cort.
 Peru, to be taken every two hours.   This was continued
 until  11 o'clock A. M. of the 27th, when the paroxysm
 returned.
    28th. Finding him free from fever, I gave him 20 grains
of the Cornus Sericea in powder, every three hours, which
was continued for several days: he has had no return of his
fever, May 6. 1803.
    It may here be added, that this  species of the Cornus
 was used by the Physicians of the French army in America
during the Revolution, as a substitute for the Peruvian
 Bark.
    On the subject of the Cornus Florida, I have received a
communication, through the hands of my friend and fellow
graduate Mr. Warmsley, from Dr. Amos Gregg of Bristol
Pennsylvania, which will be found doubly interesting; first,
because it comes from a practitioner,whose success and zeal
for the promotion of medical science, endears him to his me-
dical  brethren—and, secondly, because his opinion of the
 Cornus Florida is founded on an experience of twenty-three
years practice with it.  The following is an extract of the
 communication.
   " About the year 1778, during the American Revolution,
the  great scarcity and high price of the  Peruvian Bark, and
the  embarrassment from the want  of it,  induced me  to
sceaich for a substitute. With this intention I tried the yel-
low Poplar, in which I was disappointed.   The common
 Dogwood (Cornus Florida) was the next which I selected.
 And  having  at  that time  the intermittent fever, I took
several ounces of the decoction of it, which effectually cur-
 ed me, though it produced some pain in my bowels, which
was relieved by a few drops of Laudanum.  This property
 of affecting the bowels with pain, I found it to possess  only 
49
in its recent state, and never after it was twelve months old,
did I find it disagree, in exciting pain, cathartic or emetic
effects.  I have, therefore, at different times had considera-
ble quantities well dried and pounded, so as not to be with-
out it in my shop for tweenty-three years.  During which
practice, I have found its virtues, such as to convince me
that it was not  inferior to the Peruvian Bark in curing in-
termittents, nor inferior as a Corroborant in all cases of
debility.  I must observe,  however, that I have  generally
given the Dogwood in doses of 35 grains.  Which I have
always found equal to 30  of the Peruvian Bark.  I have
used the Dogwood in several other cases, the most interest-
ing of which are, first in a dropsical patient, who, after a few
days of violent pain in his legs, had them swelled to a very
large size, and considerably inflamed: soon after, small blis-
ters appeared upon them, which in  eight-and-forty hours
turned of a dark purple colour j at this time I gave him 30
grains of the Dogwood in powder, with 6 grains of Virginia
snake-root every half hour for two days, and once an hour
for the succeeding 24 hours.  The man recovered.
    " The other was a patient, who, by accident, had a great
portion of the muscular  part of his leg torn off, the weather
being excessive warm, the purulent discharge soon became
very  great,  and offensive.   I gave him the Dogwood
joined with the Snake root as above, the  man soon recover-
ed, and is now living.   I have  often  used the Dogwood,
joined with Gentian, Columbo, Camomile, and with  Aro-
matics in bitters, and have found it equal to the  Peruvian
Bark, and therefore concluded it is a valuable medicine."
G 
50
                   APPLICATION.

    WHEN we look back upon the similarity between the
Comi and the Cinchona, in their sensible qualities, in their
Chemical Analysis, and their  similarity of action on the
incised, and dead fibre, and particularly when we view their
similar  operation on the healthy and diseased subject, we
cannot but receive the most flattering inducements to es-
timate these provident gifts of Nature.   And when we
reflect upon the causes  of the  various  forms of disease,
which  are  the endemics of our  country,  we cannot but
receive  additional inducements to regard the Corni as the
most  valuable vegetable, which Nature, in the prolificness
of her bounty, has  scattered through the wide forests of
North America.    For so long as  the mouldering ruins of
our swamps, and the uncultivated condition of our marshes
shall afford materials for the peccant operation of an Autum-
nal sun, we shall view, with peculiar delight, the virtues of
these two  vegetables,  which  inherit  the  two essential
characters of the most valuable  division of the  Materia
Medica; I mean bitterness and astringency ; to the ' happy
union' of which the Corni  have  a claim, as respectable
as that  which has  procured for the  Peruvian  Bark a
celebrity as extensive as the bounds of  rational medicine.
Indeed  so  striking is the similitude, so exact the result,
from comparative trials, that in this attempt to recommend
the Cornus Florida and  Sericea, to the attention  of prac-
tising physicians,  I cannot even review  the forms of
disease,  in the particular states of which  the  Corni are
indicated, without encroaching  upon the reputation of the
Cinchona:  for, in  truth, it  may be said, that in whatever
form of disease the Cinchona has been decidedly  sendee- 
51
able, the Corni will be found equally so.   And if we make
allowances for the chances and inducements to adulteration
in the former, for our relationship to the latter, for its wide
extent through the  very soil in which are  engendered  the
seeds  of, those maladies,  their virtues are  fitted  to  re-
move, we must acknowledge their superiority. Experiments,
of a diversified nature, warrant this conclusion. They are,
like the Bark, bitter and astringent in the mouth, tonic and
febrifuge in the stomach, and their  chemical analysis afford
results perfectly analogous. But shall I,  on this account, re-
commend, in Intermittents, Remittents, Coleras, Diarrhoeas,
and Dyssenteries, the corroborant virtue of the Corni,  be-
cause  the same virtue,  in the Cinchona,  has been said to
be their specific remedy.  This would, indeed, be following
the  usual mode of  introducing new medicines into notice.
But would it not be adding a specific to Nosological titles,
and one more powerful nostrum to the long catalogue of
Empyricism?
    Had the improvements in Pathology and Therapeutics
kept pace with the rapid enlargement of the Materia Medi-
ca, an attempt at this day to have added one more article to
the  latter,  would  have been regarded  as  fruitless and
unnecessary.
    But while the  medical mind was busily employed in
drawing nosological distinctions, and wasting the efforts of
genius in searching for specifics, the embryon of  rational
science  was  rising  in the western horizon.   In its growth
it viewed,  with grief and horror,  the species of  diseases
*multiplying themselves in numbers and augmenting their
malignity.   And no sooner had it arrived at its zenith, than
its first act  was to liberate Medicine  from the trammels
    * In proof of which the following is given as an example.
    Sauvage has, in his Nosology, 10 classes,  44  orders, 300 genera.
with species and varieties innumerable.
   Linnaeus has 11 classes, 37 orders, species proportionally numerous.
   Vogelius has 11 classes, containing 560 genera, with their species and
varieties proportionally  numerous. 
52
  of Nosological complexity, and restore to disease that unity
  and simplicity, which allied it with its proximate cause.
     Fully impressed with  the  inestimable  value of this
  improvement in Medicine, which does distinguished honour
  to its author, I shall neglect the  Nosological order: nor
  shall I say that the Corni are indicated in  Remittents  or
  Intermittents, merely because they consist  of paroxysms,
 remissions or intermissions, but shall pay particular attention
 to that state of the system, which affords the only rational
 indication for Tonic Medicine.  I assume it a truth,  suffi-
 ciently established by the illustrious  Professor of Clinical
 Medicine,  in this  University, " that disease is the same,
 however variously it may be modified by  age, constitution,
 climate,  season,  remote or  exciting causes, or by  its
 duration."  But if none of these circumstances, are sufficient
 to establish a specific difference in the nature of  disease,
 what criterion are we to adopt,  by which we may regulate
 the administration of the  Corni, or any other article of the
 Materia Medica, all of which,  though differing greatly in
 their respective qualities,  have nevertheless an appropriate
 point in the scale of morbid excitement? The very circum-
 stances carry along with them the answer; namely,  the ex-
 isting state of the system, which is to be judged of by the
 season, age, and duration, &c. but more particularly by the
 state of the arterial excitement, as pointed out by the pulse.
 So important  is the  nosometrical power of the  pulse  in
 shewing the force of arterial action in the system, that it
 may emphatically be called the alter occulus of physicians.
    In taking,  therefore, this nosometer of  the system for
 my guide,  my labour in the application of  the curative
 powers of the Corni, will  be greatly abridged.  Instead of

   Cullen, 4 classes, 59 orders, 350 genera, with their species and varieties.
   Sagarus,  13 classes,  54  orders, 350 genera,  containing 2,509 species
with their varieties.
     " Hei mihi! Tot mortes homini quot membrana, malis que,
    Tot sumus infecti mors ut medicina putetur." 
53
 tracingtheirapplication through the catalogue of Nosologists,
 I am guided to that particular state of the system, which
 may occur in every form of disease, and which whenever
 it does occur, calls for the Corni, or such medicines as pos-
 sess similar virtues.
    In tracing the pulse, in disease, we find it in two very
 opposite states.  In the one we  find it full, strong,  hard
 and frequent, accompanied with  heat of body, thirst, rest-
 lessness,  &c.  To which state has been attached  the term
 of Inflammatory action.  In the other it is weak, small and
 quick,  accompanied  with  debility  and prostration  of
 strength,  heaviness and dejection of spirits, and various
 other circumstances, which has  attached to this state, the
 various terms of nervous, jail,  hospital, ship, petechial,
 putrid or typhus fever.  Every form of disease in its various
 modifications, approaches more or less near to one of these
 two opposite states, between which there are several grada-
 tions of morbid excitement, indicated by corresponding de-
 grees of arterial action.
    I have only, then, to say that the Corni or other tonics,
 whose  virtue consists  in  increasing  and supporting the
 strength of arterial action, and thereby removing that debi-
 lity which is the principal symptom of this latter  state, are
 indicated here.   And that their exhibition may be extend-
 ed, with probable success*, to every other form of disease,
 in proportion as it approaches to this latter described state.
    But I cannot here omit, the golden rule in  the exhibi-
 tion of this class of medicines, for the authority  of which
 we have the exalted names of a Darwin, a Rush, and a
 Barton, that is whenever in the exhibition of tonics or sti-
 mulants, the pulse becomes slower, fuller, and  stronger,
 their administration is judicious,  and should be continued;
but when on  the contrary it  becomes quicker, more fre-
 quent with an increase of heat on  the body, anxiety, and
dryness in the mouth, they are improper, and  we may
 say with Ovid, " parce stimulis,  et utere loris." 
54
    In attending to disease, as it occurs in our own country,
we perceive that some forms of disease approach more uni-
formly to that particular state, just described as requiring
tonics, than others, such are those which occur in the Sum-
mer and Autumnal months.  I shall therefore briefly enu-
merate them—In attempting which, I feel sentiments of
gratitude in adopting the  division and doctrines of the il-
lustrious Professor of the practice  of physic,  who enu-
merates six original forms of Autumnal  disease.  In all
of which the Cornus Florida and Sericea, may be employ-
ed with the happiest effects, according to circumstances—
They are, " 1. The Malignant Yellow Fever.   2. The In-
flammatory Bilious Fever.  3. The Remittent Bilious  Fe-
ver.  4.  The Intermittent Bilious  Fever.   5. Chronic
Fever, and 6. Febricula."  These  embrace all the affec-
tions of the alimentary canal, in the shapes of Cholera,
Diarrhcea,and Dyssentery; of the skin, in various eruptions,
of the Pulmonary System, in the form of Peripneumony
Notha; of the spleen and pancreas,  in  inflammations  and
obstructions; of the brain, in the shape of Hydrocephalus
and Coma; and of the arterial system, in all the grades of
arterial excitement, from the Malignant to the  Typhus ac-
tion.
    My limited time will not admit my dwelling on these
forms of disease';  all that I shall say therefore is, that the
disease which generally occurs at  this season of the year,
generally shapes itself in such a manner, as to enable us to
derive the greatest advantage from the tonic power of these
vegetables.  The remissions and intermissions which suc-
ceed to the paroxysms of morbid excitement, often presenting
favourable opportunities of conquering by the active powers
of the Corni, the growing habitudes of morbid excitement.

    On  the particular indications which may be answered
by  the small difference in the proportions of the  constituent
parts of the Corni  and Cinchona,  as pointed out in their
chemical analysis, I have but little to say, they are easily 
55
judged of.  Thus the superior  miscibility  and solubility
of  the  Corni, shew that they  may be  given in smaller
doses, and oftener repeated; whereas the more difficult solu-
bility of the Peruvian Bark, requires that it should be given
in larger doses and at longer intervals.
    When in debilitated habits along with which there is a
Dyspeptic state of the stomach, the Peruvian Bark disagrees
with the  latter, probably from its  insolubility; the Corni
should be given.
    In the Remitting fever, where the remission is not so com-
plete as to admit the stimulating resin of the Bark, the Cor-
nus Florida, as possessing less of this, may be employed.
    When an indication is founded upon great debility and
laxity of  the muscular  system,  accompanied with morbid
irritability, and probably sensibility, depending upon this de-
bility, the superior astringency of the Corni promises its aid.
    In those persons, whom from a particular state of the
bowels, the  Bark purges,  the  astringency  of the Corni
recommends itself.
    The greater antiseptic power of the Corni, claims for
them a superiority in external application, in the  form of
fomentations, &c. to sphacelus parts.
    In debility of the alimentary canal in general, and of
the stomach in particular, which gives rise to acidity in the
latter, as often occurs  in Dyspepsia,which require tonics,the
superior anti-fermentative power of the Corni, should be
employed.  For however satisfactorily physiologists  may
account for  digestion by the powers of solution,  in the
healthy state of the  stomach, there are too many evident
marks  of acidity in its diseased state, to deny the acid fer-
mentation in the latter condition of this Viscus.
    Conscious of  the imperfect  manner,  in which I have
treated this truly important and interesting subject, I must
do it the justice to conclude in the -words of Mr. Pope.
                         " If vain our toil,
        We ought to blame the culture, not the soil." 
56
    But before I take a final adieu of you, illustrious Pro-
fessors,  permit me in  this humble  manner  to return
you my most  sincere  thanks,  for the  inestimable prin-
ciples which I have received from each and all of you in
the science of medicine.   For it is from the most impres-
sive evidence I add, that it is in this University, that new
avenues to medical knowledge have been unfolded, and the
just importance of former ones established: in which Uni-
versity, the genuine principles of medicine have received a
development, and a kind of demonstration hitherto  un-
known.  And lastly, in which its students enjoy that pro-
found liberality, and indulgence in sentiment which banishes
superstition, and its concomitants blind veneration and cre-
dulity.
THE END. 
 
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