AN
Experimental Inquiry
INTO
THE PROPERTIES OF CARBONIC ACID GAS
OR
FIXED AIR;
ITS
MODE OF OPERATION, USE IN DISEASES, AND
MOST EFFECTUAL METHOD OF RELIEVING
ANIMALS AFFECTED BY IT.
BEING
AN INAUGURAL THESIS,
SUBMITTED TO THE EXAMINATION OF
THE REV. JOHN EWING, S. T. P. PROVOST;
THE
Trustees and Medical Faculty of the University of
Pennsylvania,
ON THE I2TH DAY OF MAY, 1797.
For the Degree of Doctor of Medicine.
BY JOSEPH JOHNSON,
OF CHARLESTON, (S. C.)
Member of the Chemical, and Honorary Member of the Philadelphia
Medical Society.
Quàm quæ sunt occulis subjecta sidelibus, et quæ
ispe sibi tradit spectator. 
HOR. de ARTE POETA.
Philadelphia:
PRINTED FOR THE AUTHOR,
BY STEPHEN C. USTICK.
1797. 



TO
DOCTOR E. POINSETT,
Physician of Charleston, South Carolina,
THIS Dissertation is gratefully
inscribed, as a small return for the
many instances of friendship and favour,
confered on his
Much indebted Friend, and
Sincerely affectionate Pupil,
JOSEPH JOHNSON.
TO
DOCTOR JAMES LYNAH,
Physician of Charleston, South Carolina.
PERMIT me likewise Sir, in
this manner to testify my acknowledg-
ments for the attention and information
with which you favoured, on different
occasions,
Your much obliged friend,
JOSEPH JOHNSON. 



Preface.
TO qualify the title of a Medical Pamphlet
with the word "Inaugural," is in general to give that
pamphlet a title discouraging to the reader's expec-
tations of any thing recently discovered, any thing
capable of affording much information, or even much
entertainment. For a work thus entitled, is received
as a publication of necessity, not of choice, and is
esteemed as the production of a youthful mind; conse-
quently, incapable of advancing from its own specula-
tion, truths that hereafter may prove beneficial to the
Science of Medicine, and through it, to the great
family of mankind.
This general rule, however, has some exceptions;
for by the unremitting industry of several Candidates
for medical honours, incited to extraordinary exertions
by an ambition the most laudable, publications of this
kind have appeared superior in justness of theory, in
ingenuity of manner, and in genuine utility, to all
preceding writings on the same subject; and this, in
spite of the usual impediments, from want of time and
opportunity to collect, arrange, and compile their
observations, with that systematic elegance necessary to
make them appear in a point of view the most advan-
tageous.
In this my first publication, many deficiences may
be observed; deficiences that were unavoidable, they
are, however, from having no facts collected on this
subject before hand, and from the want of opportunity
and time to experiment, as fully as I had wished. The
experiments, as may be observed from the dates, were

PREFACE.
all executed, and the compilation made within the
space of five weeks; the limited time for its completion.
It was my wish to have repeated the experiments
of Dr. Priestley, to ascertain the effects of carbonic acid
on vegetation; but the season of the year would not
admit it. The Doctor's experiments do not appear to
be made with sufficient accuracy*. I had therefore
resolved to repeat them, if posslible, with distilled water
and distilled water impregnated moderately with car-
bonic acid, using sprigs of mint comparatively in the
two waters as in his, and having the other circumstances
similar. But satisfied with what I have done; I now
submit the work "with all its imperfections on its
"head," to the candid inspection of the different
members of our Medical Republic.
* He permitted a part of  the plant to be surrounded or invested
with carbonic air.

AN
Experimental Inquiry,
&c.
SECTION  I.
The manner in which Carbonic Acid operates on the
Animal Body.
IT is not my intention in this Essay, to speak
of Carbonic Acid as an object of Natural Philosophy,
to enlarge on its history, or show its connexion with
the other branches of Science; but merely to view it
as a subject of Medical Philosophy. Much has been
written on this subject, and very able pens have been,
at different times, employed in describing its properties,
and showing its uses and effects in the different parts
of the creation. Many of the most eminent men
indeed of the present century, have thought it an
object worthy of their attention, and by experiment
and minute observation have completely ascertained its
nature, its constituent parts, and its effects on organic
matter.
What then, it may be asked, can be my object in
undertaking a subject which has been already so amply
discussed? I do not mean to repeat what these my pre-
cursors have said, to renew their labour, and recite what
they have explored:—their writings are in the hands
of every one acqainted with books, and familiar to every
man of general knowledge. My intention is simply
to resume the subject where it has been left unattended
by others, or left imperfect.
B

10
I am now therefore to consider its nature as an acid,
its component parts, and its effects on the animal body,
by an inherent positive power of its own, to be clearly
ascertained; and proceed to show the manner in
which this effect is produced; from the nature of this,
the proximate cause, to point out the most effectual
mode of relief; and then show its use in the cure of
certain diseases, with the manner in which these good
effects are produced.
The opinions of the different writers, therefore, who
have attempted an explanation of its effects I shall
briefly recite, as preparatory to this part of the inquiry,
and offer some observations and objections to each
severally as I proceed.
Dr. Priestley, when he published, entertained the
opinion that this gas destroyed the lives of animals
merely by a deprivation or want of oxigene*; for
he speaks repeatedly of the animal's being suffocated.
Dr. Goodwyn carries the idea so far, as, in his
Dissertation on the Connexion of Life with Respiration,
so justly admired, not only to assert, that life was
destroyed in a manner exactly similar to that by sub-
mersion in water, and in support of his opinion, boldly
to declare, that carbonic acid may be breathed in consi-
derable quantities provided it is mixed with atmospheric
air; but even to propose inserting its effects as the
third species of his Genus Melanœma: but of this I
shall speak more particularly, when I come to treat of
the cure. Mr. Coleman and Mr. Kite, who published
on the same subject with Dr. Goodwyn, and who
differ from him in explaining almost every point, con-
nected with the subject of suspended respiration, yet
agree with him in believing, that life is destroyed in
a manner analogous to drowning.
* This is the language of the present most admired system of
Chemistry. Dr. Priestley's literal opinion is, that life is destroyed
by the retention and consequent accumulation of phlogistic vapours
in the lungs.

11
To disprove these opinions, it will only be necessary
to refer to the comparative experiments of Dr.
W. Bache, as published in his Inaugural Dissertation,
and to those of Dr. Beddoes, in his Dissertation on
Factitious  Airs. Dr. Bache found that animals in an
artificial atmosphere of oxigene and carbonic  airs,
expired in 10 or 15 minutes; while others, equal
apparently in every respect, lived in the same quantity,
by measurement, of atmospheric air for the space of
an hour without much inconvenience. Dr. Beddoes
found that animals of the same species, of the same
litter, and apparently of the same vigour; if immersed
in carbonic acid, died in 1 1-2 minute, but in hydro-
gene not till 22 minutes.
From this we would conclude, that carbonic acid
acts by an inherent power; while azote and hydrogene
act simply by preventing the influence of oxigene from
coming in contact with the lungs; for the length of
time which life continues, when the animal is exposed
to these two gases simply, is about the same with its
duration when the animal is immersed in water.
Mr. Coleman, to support his favorite idea of collapse,
asserts, that no more of the noxious air enters the
lungs during exposure to it, than of water, in those
destroyed by drowning; but this assertion has likewise
been disproved by an ingenious experiment of Dr.
Bache.
He introduced one end of a syphon into a receiver
filled with carbonic acid, the other end of which was
fixed, by a bladder and drawing-string, to the head of a
dog: he observed the water in the receiver over which
the air was collected, to rise and fall alternately as the
animal respired. Mr. Coleman's explanation therefore
of its effects, by supposing the carbonic acid to irritate
the epiglottis, so as to make it close and prevent the
entrance of this gas, while the air previously in the
lungs is pressed out by the different exertions, and a
compleat collapse takes place, being the immediate
cause of death; must be wholly unfounded.

12
But he admits that the noxious airs* do destroy life
in a shorter space of time than submersion in water.
And how is it posslible for this fact to be explained on
his principles? is it not indirectly acknowledging, that
the noxious airs† have an operation specifically different
from that of submersion in water?
Mr. Kite, although he believes that the proximate
cause of death from noxious vapours is the same with
that from drowning and hanging, viz. apoplexy, yet
gives it as his opinion that animals, thus destroyed, are
not acted on in the same way; for he justly observes,
that they expire in a shorter time and that their limbs
continue flaccid for a greater length of time after death‡.
He then goes on to account for this difference in the
following words, "From a variety of circumstances, I
"am induced to believe, that mephitic air occasions
"apoplexy and death in two ways: first, by affecting
"the nerves of the trachia in such a manner, as to
"render the muscles subservient to respiration para-
"lytic; and, secondly, by its sedative property destroy-
"ing the action of the brain and nervous system."
That the first part of this mode of explanation,
viz. that the muscles subservient to respiration alone
being rendered paralytic, is, independent of the rest
of the body, the immediate cause of apoplexy; must
be erroneous, I infer from the general affection of the
system, in such cases of exposure, and particularly of
the sanguiferous system. Hereafter I hope to show,
not only that the paralytic state of the respiratory
muscles, is not the cause of apoplexy, but that apo-
plexy induced, is the cause both of paralysis in the
muscles of respiration, and in those of the whole system.
As to the second part, viz. that it operates by a sedative
property I hope to demonstrate to a certainty, that the
* He experimented with the nitrous air of Dr. Priestley.
† Under the appellation of noxious airs, I would include all
gaseous fluids except oxigene, hydrogene, and nitrogene or azote.
‡ See page 210, &c.

13
reverse of this is true, and that its operation is wholly
stimulant.
M. Troja*, who gives the finest history of the effects
produced by carbonic acid on the animal body, of any
author who has hitherto appeared on the subject, in
investigating the nature of the cause which produced
these effects, has first instituted an inquiry to deter-
mine whether the acid nature of this æriform fluid
may not be the property, by which, it so speedily
produces death†. After many ingenious comparative
experiments with marine acid gas, &c. he proves that
this is not the case provided that its operation as an
acid be regarded only as coagulating the blood.
This opinion, I must confess, struck me most forci-
bly when I first began to reflect on the subject. I
observed that all the acids coagulated the blood,
and carbonic among the rest; I reflected on the saline
taste of the blood; knew that alkalis would preserve
its fluidity when removed from the body; observed
that solutions of soap, the oily part of which is rendered
miscible with water, by its union with the alkaline,
were coagulated by carbonic acid, which I supposed
neutralized the alkali, so as to disengage the oil from
its mixture, and from these considerations I thought
it probable that the alkaline matter of the blood
preserved its fluidity, and that a coagulum was pro-
duced in a manner similar to that of the soap, by the
alkaline principle being neutralized. I thought this
opinion the more probable, when I knew no reason,
why carbonic acid might not act on the blood,
through the membrane inverting the lungs as effec-
tually as oxigenous gas. This opinion, however
plausible it appeared in theory, I was obliged to resign,
on seeing the experiment of Girtanner, which shows
that venous blood only has its coagulation expedited
by carbonic acid, and that arterial blood is not affected
* See Rosier's Journal, Vol 1. for 1778, p. 174.
† Ibid. p. 302.

14
by it. The fact too of the blood in those animals.
destroyed by carbonic acid, being so uniformly found
fluid, was more immediately and more certainly
effectual in refuting the opinion.
M. Troja having shown the impossibility of the
action of carbonic acid on the blood by its acidity;
premises that it can only produce death in two ways,
through the medium of the nerves, and through the
medium of the blood-vessels, as the agents of the
circulation. He concludes from abstract reasoning,
that life in cold blooded animals, as frogs for instance,
is destroyed by its action on the nervous system. He
observes that in frogs, life seems chiefly to depend on
the healthy state of the nervous system, and in some
degree independent of the circulation; for he adds,
"Otez le cœur à une grenouille, & par conséquent
"la circulation, elle sautera, elle marchera, elle vivra
"tres-long-tems; coupez la tâte à une outre, detrue-
"sez sa moelle epiniere, elle ne sautera plus, mais
"son cœur fera toutes ses functions & la circulation
"se continuera." In hot blooded animals he is of
opinion that life is destroyed through the medium of
the circulation; and that this is arrested by the fre-
quent respiration which such animals require, being
interrupted, for he observes that death comes on before
the affection of the nerves could produce disease.
He then concludes, "Celles-ci sont les causes les plus
"immediates de la mort, des animaux suffoques par
"les moffettes: je dis les plus immediates, & non
"pas les causes efficientes. Pour connoitre en general,
"la cause efficiente de la mort, il faudroit connoitre
"la cause efficiente de la vie. Consiste t-elle dans
"l' assemblage des movemens? dans l'irritabilite? dans
"quelque autre chose inconnue la cessation de celle-ce
"sera la cause efficiente de la mort."
His reasoning, however, is by no means conclusive.
That the impression is first made on the nervous system,
I can readily admit, but cannot by any means think it
possible for life to be destroyed through this system

15
singly. Neither do I agree that the arterial system
can be primarily affected: but that the disease is commu-
nicated to it by a reflected impression, is sincerely my
opinion.
Fontana, in his work on poisons, and Bergman, who
first proved the acid nature of this gaseous fluid*, have
declared that life ceases in consequence of the irritabi-
lity being destroyed. That this is true in its literal
sense, I openly deny; for, in all the dissections that I
have seen, and in those given by all other authors,
the contractility of the heart has been in no degree
less, than when the animals are destroyed by other
means. But if we consider their assertion in a more
general point of view, it will appear to be saying
nothing more than simply that life is destroyed. For if
we believe that the life of an animal depends on the
aptitude of its fibres, to receive the impressions neces-
sary to excite the motions of life, it is evident that
death must in all cases, equally depend on the loss of
this aptitude or susceptibility of impression.
Besides this, if the loss of irritability were the imme-
diate cause of death in the sense that they view it, life
could always be restored to a certainty, according to
the elegant experiment of Girtanner, by simply
inflating the lungs with oxigenous air, as he found the
contractions of the heart restored instantly as the air
enters the lungs; but this unassisted by other treatment
is found to be an ineffectual practice.
Dr. Percival, in an Essay on the Vapours of Charcoal,
says they act on the olfactory nerves first, and that
the brain and nervous system is affected by sympathy
or consent of parts†. He seems to be of opinion that
* The credit of first discovering the acid nature of carbonic acid
gas has been given to Mr. Bewley, on account of his Essay pub-
lished by Dr. Priestley in the 2d vol. of his Observations on Air.
The two publications on this subjeft, it is true, appeared about the
same time; but the preference will, by comparing the dates of the
experiments, be decidedly given to the Professor of Upsal.
† See Dr. Percival's Essays, Vol. 1. p. 338.

16
these effects on the nervous system are produced by a
sedative power; for, although he does not give this idea
in express terms, he speaks of its destroying the action
of the brain and nerves, and says, "they occasion some-
"times all the various symptoms of a debilitated nervous
"system, according as the poison is more or less con-
"centrated." He himself, however, seems to refute
this opinion by advising the common treatment of
fever for relieving its effects, viz. bleeding, cupping,
blistering and cold air, with frictions, cold water and
inflation.
Dr. Bache, who has with great accuracy and inge-
nuity of experiment, proved unequivocally, the inhe-
rent positive action of carbonic acid in the animal
body, does not venture to decide on the manner in
which this positive action is effected. He suggests,
however, several ingenious modes of explaining its
effects; he first supposes "an inherent property in
"carbonic acid gas, inducing, when combined with
"the blood, whether arterial or not, such changes in
"its nature as to banish from its dominions all oxige-
"nous gas, according to its state of concentration;
"causing it to combine with the moving parts of the
"animal œconomy, to which it is more particularly des-
"tined, thereby producing a great accumulation of exci-
"tability, which, when acted on by the ordinary stimuli
"then existing in the system, produces all the pheno-
"mena incident to submersion in that fluid." Here the
Doctor believes the excitability of the system to arise
from the oxigene absorbed into the blood, and indeed
to be the same with that principle—a  circumstance
which yet remains extremely problematical, although
Girtanner has given several facts in support of the
opinion. He likewise supposes in this, that the carbonic
acid absolutely enters into combination with the blood:
a  supposition which is highly improbable, as many
experiments show that immediate coagulation would
ensue; but the reverse of this has always been
proved by dissection. In a note, he next offers to

17
explain its operation, by supposing that it acts indi-
rectly on the blood, exhausting the irritability of the
muscles, thereby causing a rapid demand for the oxige-
nous principle, which would be consequently exhausted
from that fluid; or, he adds, it may have a compound
action, as it may act both directly and indirectly. As
these suggestions, however, will not lead to any useful
practice, I shall leave them to the unbiassed remarks
of others.
In attending to the symptoms apparent in animals
exposed to the influence of carbonic acid, I could not
but be struck with the sameness existing between them,
and the effects described by authors, as attending the
exhibition of the most powerful stimuli. To point out
this similarity, I will recite the appearances that occur
in these cases of exposure: the respiration is first
observed to be more difficult, the animal appears
anxious, the pulsations are more strong, frequent, and
impetuous, so much so indeed, that M. Troja, who
first noted the appearance, has very descriptively com-
pared the sensation communicated, to that of a column
of mercury pressed by injection, with the greatest
possible force. The animal becomes dull; a violent
head-ach comes on; the head, neck and eyes, appear
turgid; the pupils are greatly dilated; a sickness
occasionally occurs; languor and coma come on; the
heat of the body is greatly increased; convulsive
twitchings succeed; languid, slow, and irregular
pulsations are now observed; the heart appears but
to thrill—and its action ceases forever. That these
symptoms are justly stated, I appeal to the observa-
tions of others, which have been confirmed by the
different cases to which I have attended. No one
who reads these symptoms, can fail of being impressed
with the similarity existing between them and the
effects of opium. Dr. Crumpe, in his admirable
treatise on opium, in describing its effects on the body,
when taken internally, states the pulsations of the
C

18
heart and arteries as rendered quicker, fuller, stronger,
and more frequent, but that they afterwards sink to
be slower than before the dose was taken. That
head-ache, an increased slow of sweat and urine,
increased heat, tremors, vertigo, stupor, and a dimness
of sight, as in the case of Dr. Ramsay, published by
Dr.  Leigh, and quoted by Dr. Crumpe; then follow
laborious and stertorous respiration, intermissions in
the pulse, and death*. That opium is a stimulant I
think incontestably proved by the exertions and inge-
nuity of Drs. Leigh, and Crumpe; and that a substance
which produces effects exactly similar, must have pro-
perties exactly similar, will, I think, be acknowledged
by every one. That carbonic acid does produce
effects, not only similar to those of opium, but likewise
to those of other substances, acknowledged to be
stimulants, I hope to make evident.
Does volatile alkali, which is universally acknow-
ledged to be a stimulant, by its application produce
an increafed action of the pulse, and increased heat of
the body, head-ache, vertigo and death? so does carbo-
nic acid. Does the datura stramonium produce nausea,
giddiness, pain in the head, dilated pupils, &c.? so
does carbonic acid. Do ardent spirits, increase the
pulse, elevate the mind, produce an increased dispo-
sition to agility, induce vertigo with all the symptoms
of intoxication and coma? so does carbonic acid, as I
hope to prove.
The matter, however probable it appears from ana-
logical reasoning, and from casual observation, has not
as yet been fairly proved by the test of experiment,
the unerring touch-stone of truth. Dr. Dobson, it is
true, in his much admired Treatise on Fixed Air, has
strenuoufly supported this opinion, and has compared
its operation to that of electricity, which is now
universally acknowledged a stimulant. He has like-
wise attempted to prove it by experiment; but, unfor-
tunately these experiments are by no means conclusive;
* See Crumpe on Opium, p. 9.

19
as the results may as well be ascribed to the impressions
of the ingredients used, as of the gas disengaged. He
swallowed certain portions of vegetable, and of volatile
alkali, immediately on being mixed with a quantity of
lemon juice*, his pulse was in consequence raised in the
space of 15 minutes, from 74 to 80 strokes in a minute,
with a slight vertigo and glow, attended with nausea.
That the alkalis and acid, (both of which are acrid
substances) had considerable influence in producing
these effects, may, I think, be reasonably urged; as
Dr. Dobson, who ascribes the whole of the effects to
the carbonic acid disengaged, concludes that the
quantity of fixed air disengaged from that proportion
of the materials, is as great as the stomach can bear,
from the degree of nausea that was induced; but
Dr. Falconer, in his note to this part, mentions, that
he has taken, and has given to others, double the
quantity there mentioned, without producing the
smallest degree of nausea.
To avoid an interruption of this kind, I thought
the intention would be fully answered, by a sufficient
draught of aerated water, for here no acrid substance
in the mixture could interfere with the result, nor
afford to the most severe scepticism the slightest chance
for evasion.
With this intention, I procured some water impreg-
nated to a moderate degree with carbonic acid, by
Priestley's apparatus: its taste was not equal in brisk-
ness with those of Saratoga, agreeably to the opinion
of a friend who had visited that place. March 21st,
my pulse beating 72 strokes in the minute, I drank
about 10℥ of this water; in the space of 5 minutes, it
had increased to 76, in 10 minutes, to 80, in 20, to
84, in 26 it beat 84—in  36, it fell to 76, in 46, to 72,
in 56, to 68, in  60, to 64, and in 70, it beat 64. In
* He took ℈ ii. gr. iii. of salt of tartar at once, and ℈ i. gr. v. of
volatile alkali at another time, each being mixed with ℥ 1 of lemon
juice.(See Dobson on Fixed Air, p. 19).

20
this we see the pulse increafed in the space of 20
minutes, from 72 to 84 strokes in the minute, simply
by the draught of little more than half a pint of
carbonated water. In 10 minutes, when my pulse had
increased to 80, my spirits were very sensibly elevated;
but this I was unwilling, without further proofs, to
ascribe to the carbonic acid: my pulse had now like-
wise increased in fulness and strength. In 26 minutes,
when at 84, it was very full and strong, the heat of
my body was considerably increased, and accompanied
with a sense of distension and turgescence in the head.
When it fell to 72, my head began to ache, and my pulse
became weaker, and less full; and when it fell to 64,
I became dull, heavy, and much inclined to gape—the
head-ache continued. Here too, it may be observed,
that the pulse, at the end of the hour, fell 8 strokes
in the minute below its natural standard; a circum-
stance that was wholly unattended to by Dr. Dobson,
and which is a material consequence, as it so evidently
strengthens the analogy of its operation to that of
acknowledged stimulants.
These results I was led to expect from the infor-
mation given me by my friend and fellow graduate
Dr. S. Cooper, respecting the effects of the acidulous
waters of  Saratoga. He mentioned that he had
uniformly observed an increased flow of spirits, on
taking a draught of these waters, with an alacrity to
which he was a stranger without it; his sensations
always, on such occasions, corresponded with those
attending the use of a moderate quantity of wine. In
this respect, too, he observed it to resemble diluted
wine, that it never did, although taken in large por-
tions, produce that heaviness and oppression at the
stomach, which is observed to attend a large draught
of common, or spring water. The disengaged air,
it is probable, stimulated the stomach, like the diluted
wine, so as to promote its own discharge. Dr. Sea-
man, who has with much accuracy analized these
waters, in speaking of their medical virtues, has like-

21
wise very expressly declared, that "in some persons,
"they induce a degree of inebriety similar to wine;
"they generally increase the appetite."
This experiment was repeated frequently, and
always with the same results, viz. an increase in 20 or
25 minutes, of pulsations from 8 to 12 in the minute,
and as uniformly a diminution at the end of the hour,
of from 4 to 8 strokes in the minute.
I thought it necessary, however, to repeat it in a
larger proportion. March 23d, having prepared some
water impregnated with the acid, somewhat more
highly than the last; I drank a little better than
three half pints, my pulse beating 60 strokes in the
minute. My pulse, in
5 minutes, beat 60
15 64
25 68
35 72
45 76
55 84
65 80
80 72
95 64
120 60
In 25 minutes after taking the draught, when the
pulsations were 68 in the minute, my pulse had evi-
dently increased in fulness and strength. I now felt
more cheerful, with a disposition, as I thought, to be
mischievous. When from 76 to 84, it beat violently,
with a throbbing in my temples, a disposition to ver-
tigo, and occasionally, an unconsciousness of what I
was doing. When it returned to 80, it was weaker,
and less full; when from 72 to 60, I became dull,
languid, and sleepy; when to 60, I was no longer
able to refrain from dosing, and actually fell asleep
while feeling my pulse.
Having previously dissolved three ounces of sugar
in seven ounces of water, with the addition of half an
ounce of yeast, it had just now commenced a moderate

22
fermentation. I therefore, immediately, while my
pulse was at 60, from the effects of the previous
portion, drank this fermenting mixture. My pulse,
in
5 minutes, beat 64
10 67
15 72
20 72
30 76
40 72
55 60
70 56
I now ceased to observe its variations. My sensa-
tions, during the operation of this draught, were, in
some respects, different from those of the preceding.
My heaviness, and dull head-ache, left me as my pulse
rose, and when it was at 76 I felt cheerful and calm.
A slight head-ache, however, succeeded, but no dullness,
or disagreeable sensations; in the morning after, I
felt as languid as if I had been using severe exercise;
my head felt heavy, and my eyes were dull, and some-
what swollen.
Knowing it to be very difficult to excite intoxica-
tion in myself, I prevailed on a friend, who was some-
what more irritable, to take of the same water, that
had produced the last, and most remarkable effects on
me. He drank a pint of it, which, in the space of
25 minutes, raised his pulse from 88 to 96; and, at the
expiration of the hour it fell, as it had risen, through
all the usual changes, down to 76. While it was
rising from 92 to 96, his pulse became fuller and
stronger, attended with a throbbing in his temples,
and a sense of warmth from his stomach, diffusing
itself through his body. His pupils were now greatly
dilated, and an evident vertigo came on; so that
objects appeared to rotate, and dance before his
eyes. Here it was remarkable, that immediately after
each accession of vertigo, his pulse fell 3 or 4 strokes
in the minute; but soon after, resumed its former
force, increasing till another attack of vertigo came on.

23
He seemed much alarmed at each sensation of this
kind, fearing that he should fall, or be injured by the
objects apparently moving about him; to this fear
I ascribed the sinking of his pulse, which returned to
its increased state of action from the influence of the
carbonic acid, till another attack was produced.
Having now ascertained its action on the body,
through the medium of the stomach, I thought it
necessary to determine whether it would produce effects
of the same kind when thrown into the intestines.
March 22d, I injected into the rectum of a friend, by
means of a bladder and pipe, about half a pint of
carbonic acid gas; his pulse being previously found to
beat 58 strokes in the minute. Here the results were
different from what I expected, and different in some
respects from those in the preceding experiments, but
not less satisfactory. His pulse did neither rise nor fall
in the regular order there described, but would increase
only in proportion as he observed the air pressed
downwards, by the peristaltic action of his intestines,
and irritating the sphincter to be discharged; it then
rose 6, 8, and 10 strokes in the course of 6 or 8 minutes,
and would fall again gradually as this subsided. His
pulse once was observed to beat 68 strokes in the
minute, and had increased proportionably in fulness
and force. He then complained of considerable unea-
siness in that part, and a smart head-ache—his pulse,
after these sensations went off, sunk to 52*. These
variations were observed to continue until the air was
discharged.
From these appearances we not only conclude,
that carbonic acid gas acted as a stimulant to the
* Dr. Dobson has taken no notice of the pulse in his experiments,
after it descended to the original standard. In these, however, we
find an additional proof of the stimulating operation of carbonic
acid gas; a proof advanced by the strictest analogy, with the effects
of substances acknowledged to be stimulant—I mean the uniform
sinking of the pulse below its natural state, after the increased action
had ceased.

24
arterial system, through the medium of the rectum, but
of the rectum alone compared with the other intestines;
for the pulse actually fell below the natural standard
when the air returned to the colon*.
As most of the stimuli, which produce their greatest
effect when applied to the stomach, will likewise produce
some effect on the body by their influence through the
skin; it appeared highly probable that carbonic acid would
affect the body through this as a medium, in a manner
similar to these last noted. I was especially led to this
expectation, by reflecting that the lungs, through which
its greatest impression is made, should be considered
merely as an extended portion of the external surface of
the body. Landriani, indeed, has given an experiment
which, if it had been proved just, would be decisive
in the question; but the experiments of M. Troja†,
and those related by Dr. Bache‡, disprove the accu-
racy of his decision.
In cold blooded animals, however, as frogs for
instance, M. Troja tells us he found the fact strictly
true, viz. that life in them was destroyed by the
exposure of the body singly to the influence of carbonic
acid gas, the animal breathing freely in atmospheric
air during the whole time, by means of a tube fixed
by ligatures in the trachia. If life then is destroyed
in animals supplied with lungs and well formed respi-
ratory organs, by the expofure of the body alone to
the action of carbonic acid, it would surely be affected
to some degree by the same exposure, in other animals
that are only different in having these organs more
completely formed.
* Does not this point out the necessity of having those injections,
which we with to act by stimulating the body, comprised in as small
a bulk as posslible, that being merely thrown within the rectum,
they may there exert their stimulating power fully, without pro-
voking by their bulk the increased peristaltic motion of the other
intestines, so as speedily to be returned.
† See Rosier, p. 218.
‡ See Bache, p. 18.

25
In order to prove the justness of these speculations;
March 4th I found my pulse to beat while sitting up,
76 strokes in the minute. Then stripping I got into
bed, and having fixed the clothes in contact with my
body, sufficiently close and uniform, I discharged from
four bladders introduced in succession under the bed-
clothes with care, carbonic acid to the quantity of
about two gallons. My pulse rose in
5 minutes to 81
10 84
15 86;
my face began to burn, and I was sensible of a con-
siderable head-ache. These appearances were not
sufficiently satisfactory to my mind, as they may be
supposed to arise from the greater warmth of the bed;
even the increased frequency of the pulse may be
ascribed to this cause, although it should have been less
in the recumbent position, which I then preserved, than
while sitting up.
To give the matter a fair trial, March 6th, I stripped
to my shirt, and entered a brewer's beer tub, which
had not yet been cleared of the carbonic air after the
liquor was run off. My pulse which before I entered,
was found to beat 84 strokes in the minute, stood in
2 minutes at 84
5 88
10 90
15 120.
The atmosphere of carbonic air extended, as I found
by the extinction of a candle, no higher than about the
pubis; I therefore at the end of 10 minutes kneeled
down, that my body likewise might be invested by it:
then followed the remarkable increase. The weather
was rather cold, and although naked, I did not feel any
inconvenience from my exposure, being warm indeed,
or at least, very comfortable in every part except my
hand which was held up, while my friend Dr. S.
Cooper attended to my pulse.
D

26
It might be objected, that these effects were possibly
produced by inspiring a portion of the carbonic air at
the time; but this I cannot admit, as the carbonic air
was found by the test of the candle to hold, from its
gravity, that determined height, as effectually as a
fluid of still greater specific gravity, as water for instance.
I am unwilling to admit it likewise, because my respi-
ration during the whole time was perfectly calm and
free, being no ways laborious or difficult, which cer-
tainly would have been the case, had the impression
been made on the lungs. When between 10 and 15
minutes in this situation, I was sensible of a prickling
on my legs and thighs, which probably was occasioned
by the action of the surrounding medium; but this I
will not urge, as the same has been observed from
the motion of the hairs, &c.
To prove the stimulating operation of carbonic
acid in another point of view, April 5th, I filled a
small glass, (of a proper size to inclose or cover with
its mouth the surface of my eye) with carbonic acid by
means of a syphon, and I applied it to my eye while
held open. The smarting irritation was so considerable
that in half a minute the tears flowed rapidly; in one
minute, however, it began to abate and in 1 1-2
minute I felt no more inconvenience. I then applied
to my eye while open, a stream of this gas issuing from
powdered marble and diluted vitriolic acid mixed in an
oil flask. In 1-4 of a minute the irritation was
evident, but continuing the application for 1 1-2
minute, the smarting and pain was so considerable that
I could no longer endure it. My eye was now greatly
inflamed, all the blood vessels of the Tun. Conjuncta
being distinct and turgid with blood, the whole surface
of the opake Cornea  was covered with blood vessels.
March 19th. In a puppy that had been strangled,
the thorax was opened and the heart shortly after began
to act, but ceased at the end of 1 1-2 minute. The
carotid artery was then opened, and a small aperture
being made in the pericardium, I injected carbonic acid

27
into it by means of a bladder and pipe; the heart
instantly renewed its contraction, and the blood began
to flow from the carotid artery where divided.
As carbonic acid gas more frequently affects the
animal body through its influence on the lungs, I found
it necessary to attend more particularly to its mode of
operation when inhaled, than had hitherto been done.
Having mixed 1-3d, by measurement, of carbonic acid
gas with 2-3ds of atmospheric air, in a bell-glass over
water; I introduced a curved tube of sufficient size to
admit of free respiration, and inhaled the mixture;
the expiration was made through my nose, which I
closed at each inspiration.
My pulse which was previously found to beat 76
strokes in the minute, suddenly increased in fulness,
force, and frequency, as I became sensible of the
carbonic acid having affected my lungs; so that at the
end of 1 1-2 minute it beat 100 strokes, having increased
24 in that short space of time. My body, which was
not warm before, this, now burned with a glow of
heat, and my head seemed turgid with blood.
March 10th, I inserted the same tube into a keg
that had been filled with carbonic acid gas, by emp-
tying water from it into a brewer's tub which had just
been drained from beer. On inspiring as before,
through this tube, my pulse which beat 64, rose in
1-2 minute to 72
1 78
1 1-2 86
A friend inhaled this when much diluted with atmo-
spheric air, his pulse beating 72 in the minute; it
rose in
1-4 minute to 76
1-2 78
1 80
1 1-2 84
It appeared proper, however, that I should vary
this experiment; that I should throw aside the tube
and breathe in this air, freed from the inconvenience
of its travelling through so great a length of canal, and

28
in a manner wholly natural. To effect this, I entered
March 6th, into a brewer's tub which was about half
full of carbonic acid gas, disengaged by the fermen-
tation of beer, of which it had just been emptied.
My pulse beating 84 in the minute, I stooped and
inhaled the carbonic air immediately from its surface,
where in contact with the atmosphere. Immediately
my pulse increased in fulness, tension, and force; and
was found to beat 100 in the minute, having become
bounding and irregular*. My respiration became
exceedingly difficult, laborious, and stertorous; my
body which before was not warm, now burned with
a glow of heat attended with profuse perspiration; my
temples throbbed; my neck and head seemed greatly
distended, and turgid with blood; and, in short, my
sensations were those of the most excessive plethora
that can be imagined. My eyes now seemed violently
distended, and my sight became dim, and almost entirely
lost—the loss of sensation would probably have been
the next in succession†. During the whole of these
violent symptoms, my mind continued calm and per-
fectly rational; I attended to the different sensations
and their order of accession; and among these a circum-
stance that clearly evinces the stimulating operation of
this gas, could not escape my notice. I observed
during the commencement and progress of the plethoric
* Dr.  S. Cooper attended to these changes as they occurred.
† This has previously been tried by that intrepid, but unfortu-
nate experimenter the young Pilatre de Rosier. The only account
of which that I have been able to find, is in Chaptal's Elements of
Chemistry, related as follows. "He caused himself to be fastened
by cords fixed under his arms, and descended into the gaseous
atmosphere of a back of beer in fermentation. He had scarcely
entered into the mephitis before slight prickings obliged him to
shut his eyes; a violent suffocation prevented him from respiring;
he felt a giddiness, accompanied with those noises which charcterize
the apoplexy: and when he was drawn up, his sight remained
dim for several minutes; the blood had filled the jugulars; his
countenance had become purple; and he neither heard nor spoke
but with great difficulty; all these symptoms, however, disappeared
by degrees."

29
symptoms, an evident distension, and nearly compleat
erection of the penis, which subsided on my rising
and removing myself from the action of the cause*.
A smart head-ache came on after this, and continuing
for half an hour, then abated; but did not entirely go
off during the whole day—I continued somewhat
languid for this and a part of the next day.
It is an opinion almost universally adopted by medi-
cal philosophers, that cold has an operation on the
animal body, according with the idea conveyed by the
term sedative†; that is, an operation suited to coun-
teract, prevent, or remove the effects of stimulating
substances. If this be received, the reverse will like-
wise be true, viz. that stimulating substances will coun-
teract- the effects of cold, and this will not, I expect,
be denied by any one. To take advantage of this
consideration, and prove in the most decided manner
possible, that carbonic acid gas acted as a stimulant on
the animal body; I caught March 24th, two young
mice of nearly their full growth, of equal size, of equal
strength apparently, and probably of the same litter,
as they were taken together in the same trap. I
exposed them in 2 oil flasks to a refrigerating mixture ‡;
the mouse A. in simple atmospheric air, the mouse
B. in an artificial atmosphere, composed of 1-3d, by
* May not this become a safe and efficacious article among those
of the Materia Medica, called Aphrodisiacs ; the person into
whose return the carbonic acid gas was injected, very pointedly
noticed the same appearance, and afcribed it to the same source.
† The term is here received in compliance with the usual language
of physicians, although I entertain doubts of its propriety; for I
cannot conceive of a substance producing a real impression on the
animal body, unless that impression be made by a kind of irritation,
which must be the effect of a positive stimulating action. Dr.
Cullen defines sedatives, " those medicines suited to reduce the
motions, or power of motion, in the body."
‡ This was made by the solution of 11 parts muriate of ammoniac,
10 parts nitrate of pot-ash, and 16 parts sulphate of soda, in 32 parts,
by weight, of water; the thermometer stood at 24° while they were
dissolving. 

30
measurement, of carbonic acid gas, and 2-3ds of atmo-
pheric air mixed intimately by agitation with a small
quantity of water.
The appearances noted were as follow:
in 5 minutes—both very uneasy, and jumping
vigourously to effect an
escape.
8 A. seems asleep, B. still jump-
ing.
10 A. still moves, but is lying on
his side, B. is scratching, and
attempting to climb the sides
of the vessel.
11 A. is dead, B. still scratching
the sides of the vessel.
15 B. is just motionless.
These results prove to a certainty, that the carbonic
acid in the mouse B, where all other things were equal
between the two, prolonged its life by a stimulating
operation, for the space of 4 minutes in 15 beyond
that of its fellow A.
This being, I hope, established, I proceed in the
next place to explain my opinion of the manner, and
order in which life, through the medium of the dif-
ferent parts or sub-systems of the body, is influenced
by carbonic acid gas. Of these I believe its immediate
and primary operation, like that of opium, is exerted
on the nervous system; by the nervous system its
stimulating effects are communicated to the muscular
fibre, and is there made evident, by the consequent
increased action of the arterial system, which does, and
must invariably, take place. The increased arterial
action being disproportioned to the strength in the other
parts of the body, and in the brain particularly, there
produces congestion and effusion, by which apoplexy
being induced, the functions of the animal body are
instantly arrested.
That its first operation is on the nervous system, I
infer from the action of this being most violent on the 

31
lungs, which are known to be little more than a mass of
cellular matter, but capable of communicating impres-
sion. To illustrate this by analogy I will only instance
the immediate increase of the pulse on taking into the
stomach a portion of ardent spirit or laudanum, or by
the impression of volat. alkali on the sniderian membrane
all which effects must surely be produced through the
medium of the nervous system.
If an objection be made to the possibility of stimu-
lating the system by an impression on the lungs, I
would obviate that objection by observing that the
body is as truly nourished, in some respects, by the
lungs, as by the stomach. If oxigene be admitted as
necessary to the very existence of the different parts of
the body, and even of the bones*; and if it be admitted
that this is received into the body through the lungs in
respiration, the observation is just. But the stomach
is not only furnished with the power of supporting
life by supplying the body with nourishment; but
likewise of being a part capable of receiving and com-
municating impressions made on it by stimuli, so as to
prolong life when it would otherwise sink for want of
nourishment†. Who then can doubt of the lungs
being capable of communicating impressions like the
stomach to the rest of the body, when like it, the lungs
are found to have a very powerful agency in supporting
the system by supplying nourishment. The effects
produced by exposure to the vapour from spirits, are
exactly the same as those of which we have been
speaking, viz. head-ache, vertigo, &c.; the manner in
which they are produced must likewise be the same in
every respect.
* The bones of animals consist of phosphoric acid and calcareous
earth—the phosphoric acid is compofed by the union of oxigene with
phosphorus; without this principle, therefore, the bony fabric
could no longer avail in giving solidity to the body.
† The inhabitants of Asia, and of India more especially, are
supported for weeks in the time of famine, by the use of opium
alone. (See Lind on the diseses of hot climates.) 

32
Oxigene is known to give force and strength to the
circulation; its mode of effecting this, however, I
believe to be essentially different from that of carbonic
air : the one acts by being absorbed into the mass of
blood, and thus imparting to it: that property, by
which it is capable of affording the stimulus to the
heart and arteries which is necessary to keep them in
motion; the other, as mentioned before, by stimulating
the nervous system.
It has been advanced as an objection to the stimu-
lating operation of carbonic acid, that mead, in which
this acid abounds, is incapable of producing intoxica-
tion. A fact like this, if just, would indeed prove a
powerful argument against the probability of our
opinion. That the assertion is made without founda-
tion, and that it is erroneous, I am satisfied by the
information of a friend whose accuracy of observation
and candour in science, has been uniformly admired by
his acquaintance. He told me in the presence of
several of my associates, that he had repeatedly observed
vertigo to a considerable degree produced in himself by
drinking mead*. That I might, however, be con-
firmed in this by my own observation, I drank April
5th, about ℥ 12 of brisk mead. My pulse previously
beating 84 in the minute, was found in
3 minutes at 86
10 90
20 80
30 78.
In a friend whose pulse beat 92 in the minute, it rose
in the space of 10 minutes to 100, and on sinking at
the end of 20 minutes to 90, was restored by another.
copious draught to the number of 100 ; this increase
was observed, although our pulses should have sunk
without the draught, because we had just come from
* This I have stated in a pointed manner, because of my not
having had an opportunity of being much acquainted with the effects
of mead when drank to any quantity: the same may be familiar to
others. 

33
walking in a warm sun, and were then sitting still in a
pleasant situation.
That this increased arterial action does take place,
I prove by the state of the pulse, which has always
been noted; from the increased heat of the body, and
from the blood being found fluid or dissolved on dis-
section: this we can only explain by considering it
disorganized, torn, and rent to pieces by the excessive
action of the vessels.
That apoplexy is the immediate cause of cessation in
the vital functions, I infer from my own sensations of
plethora about the head, from the turgescence of the
neck and face, from the distended or projected state of
the eyes, the dilated pupils, the coma, the stertorous
and laborious respiration; from the dissections of
animals thus destroyed as described by authors; they
mention the blood-vessels of the brain as turgid with
blood, with bloody serum occasionally effused in the
ventricles, and from those of my own, where, in addi-
tion to these I found red blood effused between the
dura and pia mater. Lastly, from observing a para-
lytic affection of the fore and hind leg, on the same side
of an animal that I had restored to life. That this is
the case, I further prove, from the case related by
Dr. Percival, of a cook who exposed himself over
charcoal fires; he was afflicted for a year with acute
pains in his head, which were followed by a paralytic
affection of his limbs.
These opinions, I am the more inclined to support,
from the propriety of practice to which they lead, in
relieving animals apparently dead from exposure to the
influence of carbonic acid gas.
E 

34
SECTION II.
The method of relieving Animals apparently destroyed by
Carbonic Acid Gas.
THE opinion of life being destroyed, in these
cases, by the simple absence of oxigene; I hold to be
improper, not only for the reasons advanced above, but
likewise on this consideration, that it leads to inert and
even injurious practice ; injurious, as it would exclude
the use of more powerful and efficacious remedies. If
this were just, the simple inflation of the lungs, with
atmospheric air, would effectually remove the disease;
but unfortunately the reverse of this is true. Dr.
Bache gives the case of a mouse and a dog that con-
tinued to breath, the mouse for five minutes, and the
dog three times, after they were removed from the
influence of this air*. Dr. Percival quotes two cases
of the same kind†: "a prisoner who had been exposed
"to the vapour of charcoal was found pale, speechless,
"and without motion ; afterwards he spoke incohe-
"rently, was seized with a fever, and died. Two boys
"went to warm themselves in a stove room heated by
"charcoal ; in the morning they were found destitute of
"sense and motion, with countenances as composed as
"in a placid sleep. There were some remains of pulse,
"but they died in a short time."
From these cases it is plain that pure air inhaled,
Can have no effect in restoring life. No assistance was
offered them as far as we can learn, and it is evident,
that if the depressed state of the system was not
relieved by evacuants, death must ensue with equal
certainty, that it would in a similar state from common
fever. If carbonic acid acted by destroying or
abstracting the irritability, it would here be certainly
restored, according to the experiment of Girtanner,
* See p. 65. † See p. 337. Vol. I. 

35
which shows that the contractibility of the heart imme-
diately returns as the air enters the lungs.
Mr. Kite, whose opinion on this subject we have
already noticed, in speaking of the cure*, recommends
inflating the lungs with pure or deplogisticated air,
"which, he observes, seems well adapted to neutralize
"and correct all kinds of mephitic effluvia." But as
this is not at all times eafily procured, he advises Am-
ple atmospheric air, and adds, "I think it will answer
"this purpose very effectually; for the affinity which
"exists between phlogisticated and dephlogisticated
"air is so great, that the dephlogisticated portion of
"the atmospheric air will combine with the mephitic
"vapour; and by frequently repeating the operation,
"its noxious property will soon be sufficiently altered."
How great a want of chemical knowledge is here
betrayed! no one of the gases, except the nitrous air
of Dr. Priestley, has any change effected in it, by
uniting, as it would in the lungs, with oxigenous air;
and in this one case a horrid change indeed, for the
worse, would be produced, as nitrous acid gas would
be instantly formed.
For relieving the effects of carbonic acid he advises
the vol. alkaline air to be inhaled with the same
intention, viz. neutralizing and correcting its acid
property. This idea must surely be looked on as
ridiculous, for alkaline gas being itself a powerful
stimulant will produce effects exactly similar. As well
might he, if called to a patient who had swallowed
caustic alkali, (for it it on the same principle percisely)
think of pouring the vitriolic or nitrous acid down his
throat to correct its caustic nature.
As the cure of all diseases depends in a great measure
on the justice and accuracy of the ideas we entertain
respecting the nature of their proximate cause, I would
reject these ideas as highly improper. It has been
shewn that animals die after being exposed to carbonic
* See Kite's Essays, p. 213. 

36
acid, although they had been removed while breathing;
if the above principles were just, it could not have
ceased, as the blood continued to be supplied with vital
air by respiration. But if it be believed, that death
is produced by the violent impression of a very power-
ful stimulant on the body, occafioning an affection of
the arterial system, similar to that in the most inflam-
matory state of fever; and that this stimulant excites
a peculiar determination of the arterial action to the
brain, we will then not only arrive at a complete
explanation of all the phenomena, but likewise have a
fair and pleasing prospect laid open before us for
relieving its most dreadful consequences.
In violent attacks of synocha fever, we immediately
prescribe cold applications and copious blood-letting;
in cases of apparent death from apoplexy we prescribe
copious blood-letting without hesitation, and with effects
the most evidently advantageous. In affections then
of the same nature exactly, although excited by different
causes, the same treatment should without hesitation
be adopted. As the head is found, from the phenomena
of death and the appearance on diffection to be the seat
in which the greatest disease exists, our efforts should
be more immediately directed to the relief of that
particular part. For this purpose the jugular vein or
temporal artery should be opened and ice applied to,
or cold water thrown over the head more especially,
and likewise the whole of the body.
To prove the propriety of this practice, March 7th,
having destroyed a cat by immersing it under water
into a bell-glass filled with carbonic acid gas, procured
from powdered marble and diluted vitriolic acid, it was
withdrawn after being exposed 3 minutes, and 1
minute after it ceased to show signs of life. In 3
minutes after the application of the ice, its heart began
to beat, cold water was now constantly thrown over it,
its respiration became evident and constant, and in 5
minutes it made an attempt to rise. The pupils of the
eyes which had been greatly dilated, now contracted 

37
to nearly their former size, and the body became
exceedingly hot, the cold water continued to be thrown
over till it ran about freely. When the cat had thus
far recovered, we immersed her as before, and with-
drawing her after the same length of time, cold was
applied in the same manner for the space of 4 minutes
before her heart was found to pulsate; when one
inspiration was observed, we opened the jugular vein
with a lancet; immediately on the first discharge of
blood she began to move, her pupils now contracted
rapidly, and the heat of her body as before was greatly
increased. The pulse was now found to beat rapidly,
being at 200 strokes in the minute, and in 4 minutes
after had descended to 152; she then moved about
the room, but with evident paralysis of the extensor
muscles, the fore and hind leg indeed of the left side
was evidently paralytic for a length of time. Here
the effects of bleeding were so decidedly beneficial as to
enforce attention, even if we were not satisfied of its
propriety, in reasoning from first principles; for when
the blood began to flow she moved her head and
attempted to rise.
In addition to this Dr. Bache informed me, that in
one case, he restored life to a cat that had been confined
in carbonic acid for the space of 15 minutes, 12 at least,
after life had to all appearance ceased, by the applica-
tion of cold water, it being frequently dashed over the
body.
Dr. B. Duffield, of this city, has obliged me with
the history of a case of asphyxia from the same cause
in which the treatment here recommended, was proved
in the clearest light possible, to be completely success-
ful. * "A young man 18 years of age, by name
"Isaac Turner, apprentice to Nicholas Pickles, being
"healthy and robust, was prevailed on by the promise
* This the Doclor was so obliging as to dictate while I com-
mitted it to paper.

38
"of 6 doll. to attempt the recovery of a watch
"belonging to a French gentleman, which had fallen
"into an old confined and filthy necessary. He
"descended by a rope fixed round his body, and
"instantly sank to his waist in the filth below. He
"then stooped and began to stir about, and groop for
"the watch; by which motion it is probable he disen-
"gaged a large quantity of the noxious vapour by
"disturbing its retaining cause, and by his position
"inhaled a larger quantity of it than he would have
"done if erect. He informed me after recovery, that
"he had not stirred the filth more, as he imagines,
"than one minute, when (to use his own words) his
"head began to turn round, his stomach to be so sick
"as nearly to cause fainting; and his breast seemed
"to be buckled round with a broad strap, so as to
"prevent his breathing. In this situation he called
'with a hoarse voice to his assistants above, 'for God's
'sake! hoist me out;' but they ignorant of his situ-
"ation, neglected him, as an intelligent man present
"supposed, for the space of 5 minutes, when finding
"the rope much tightened, and not moved, they drew
"him up covered with filth, pale, and apparently dead.
"He was carried to his master's house, and I saw him
"in about the space of 5 minutes more. Being strip-
"ped, (which was easily done, as he was remarkably
"limber and flaccid, no appearance of life remaining
"but the natural warmth) I ordered two men to stand
"with buckets, and dash water over him constantly as
"he lay on the floor, the one over his head and body,
"the other over his extremeties, and the water to be
"constantly supplied fresh as it was used. In a few
"minutes he was in a cold bath completely, for the
"the floor was inundated with water, the windows
"had previously been opened; the water continued
"to be dashed cold over his body, and in 20 minutes
"the heart seemed to resume its functions; in 30 a
"feeble pulse was observed in his right arm. Shortly
"after he opened his eyes, and in the course of 

39
"half an hour more his speech returned; his pulse
"had now increased rapidly, and he begging to be
"let alone, the dashing of water was discontinued
"one hour after it first begun. In 3 hours after I
"saw him again; his face was turgid, his eyes inflamed,
"his head dizzy, and his mind confused, with a pulse so
"full and strong, as to demand copious ven. sectio. and a
"strong cathartic of calomel and jalap. The blood
"was buffy, and had a smaller proportion of serum
"than natural. The next day he looked as spiritless,
"feeble, and languid, as if he had just recovered from
"a severe and tedious illness—he was not able to
"return to work until after 21 days."
The air to which this young man was exposed,
was probably a combination of alkaline gas from the
fæces and carbonic acid disengaged by the fermenting
matters. This mixture, if such it was, has been
proved by an experiment of M. Troja, to have an
effect precisely fimilar to that of pure carbonic acid*;
the happy recovery was undoubtedly owing to the
application of cold water, so judiciously continued for
that great length of time. When life was restored by
this treatment, it is probable that the patient would
again have sunk under the violent action of the arterial
system, had it not been reduced by the liberal evacu-
ations and other treatment of fever.
The application of cold and of cold water, which
when long applied has proved so beneficial in cases of
this kind, is by no means a remedy to which we are
not familiar in similar affections. Children and the
common people use this method of relieving persons
who are found in that species of apoplexy which is
known to be induced by the immoderate use of spiritous
liquors, and which occasionally proceeds to such lengths
as to be with difficulty distinguished from the true state.
Ask them why they pump on, or pour cold water over
persons thus affected, and they will tell you, to make
* See Rosier, p. 182. 

40
them sober; that is, to reduce the excessive determi-
nation of arterial action to the brain, and thus permit
the mind to resume its supreme dictatorial function,
and the Nervous System its important office in the
animal œconomy.
The Russians and inhabitants of Siberia, we are
told, have frequent occasion for assistance in cases of
this kind, where charcoal fires are so largely employed.
They drag persons motionless and apparently dead
from the place in which they were exposed, and rub
them with snow or ice, or dash cold water repeatedly
over the whole surface of the body. This method,
we are informed, is universally practised among the
common people, and with constant success where respi-
ration has not been suspended more than an hour*.
When ice cannot be procured, may not a refrige-
rating mixture by the solution of neutral salts be applied
in bladders, so as effectually to answer every purpose ?
When neither this, nor ice, nor even water in sufficient
quantities can be procured, let us not cease to exert
ourselves in that most admirable, but too frequently
least successful of all pursuits, viz. the restoration of
life. Let us throw on what water we can get and
expose the patient to a current of air, that the
body being thus moistened, may be reduced in tempe-
rature by the evaporation: if not water, throw on
spirits, alcohol, æther, or any other fluid which by a
speedy evaporation may produce the necessary degree
of cold. 
Seeing this treatment so effectual as we are promised
it will be, we may well be surprised that it has not,
been more commonly practised in relieving the different
cases of apoplexy, in which little has been done except
the liberal application of the lancet. Apoplexy, it is
true, is not constantly relieved by these remedies. I
am disposed to believe, however, that apoplexy, as
* See Dr. Fothergill's excellent dissertation on the Suspension
of Vital Action, p. 136. 

41
Well in ordinary cases, as from exposure to carbonic
acid, &c. may be always relieved when the asphyxia
is induced by congestion of blood in the brain, or by
the distension of the vessels without the effusion of their
contents; provided these remedies be persevered in a
sufficient length of time: when effusion has taken
place the success is very doubtful. In one case of a
puppy where I failed of restoring life (perhaps by not
continuing the cold long enough) I found, on dissecting
the head, not only the blood-vessels all greatly distended,
but likewise a quantity of red blood effused on the
back part of the brain, between the dura and pia
mater.
SECTION III.
The use of Carbonic Acid in the cure of Diseases.
HAVING seen the powerful effects of carbonic
acid on the animal body while in health, we may
immediately conclude that its agency in disease would
not be less remarkable, and that like other substances
of the same properties, it might be rendered, by
modifying the quantity and varying its application,
the instrument of life as well as death, of health equally
with that of disease.
Accordingly we find by the industry and observation
of several medical inquirers, that this article has been
found most eminently serviceable in the cure of many
affections to which the human body is liable. Thus a
new branch is produced on the flourishing plant Materia
Medica, which by its beauty, vigour, and analogical
resemblance in nature and sensible properties, bids fair
to prove with the advancement of science, one of the
most valuable improvements in the healing art. This,
with most of the gaseous fluids, the properties and uses
of which have lately been investigated with much
F 

42
accuracy, ingenuity, and care, will constitute a branch
very properly denominated Pneumatic Medicine.
I now propose to inquire into the different kinds of
disease, that have been treated with this gaseous
substance and attended with beneficial influence, and
explain the principle on which this is produced.
In cases of Typhus, the remedy the subject of our
investigation, has been attended with effects the most
evidently serviceable of any almost, on the record of
medicine. Dr. Percival * and Dr. Dobson †, in the
cases related of what they call putrid fevers, have
proved this in the most pointed and decided manner
possible. They describe cases of this kind, in which
the disease had advanced so far as to be attended with
Subsultus Tendinum, a brown fur on the tongue,
frequent, fetid, and involuntary stools, a pulse from
120 to 135, delirium and even petechiæ, which were
completely cured in the space of 5, 6, and 8 days by
injections of carbonic acid into the rectum, and by
permitting it to be disengaged in the stomach by the
effervescing mixture.
A case of the same kind is published by Dr. Priestley ‡,
as communicated by Mr. Hey of Leeds. Here the
usual treatment had been carried to its greatest extent,
but the patient continued to grow worse; it was now
attended with a violent putrid diarrhœa, as it is termed,
and the patient was sinking under the discharge.
Carbonic acid air was ordered to be injected into his
rectum by means of the machine for injecting tobacco
smoke ; the heat and factor of his stools was at once
removed, and in two days every symptom of danger
disappeared.
These were unquestionably cases of that stage of
fever which we now call the gangrenous, in which
tonic and stimulating remedies are universally recom-
* See Vol. II. p. 313, 14.
† See Dobson on Fixed Air, p. 22. &c. &c
‡ See the Appendix to Observations on Air, Vol. I. Also,
Rosier's Journal, Vol. I. for 1773.

43
mended, and as constantly found to be the only ones
beneficial. The carbonic acid here must act by
stimulating the stomach and rectum, and thus imparting
the necessary degree of tone to the muscular fibre in
the rest of the system. This explanation I advance,
believing with Dr. Seybert, that no putrefaction can
take place in the living body. I would therefore with
Dr. Dickenson attribute the appearance of petechiæ,
vibices, and maculas, not to a putrefaction of the fluids,
but to a weakness or loss of power in the muscular
fibres of the capillary arteries, so as to permit them
to be ruptured by the common impetus of the blood,
and the effusion of red globules by this means to take
place in the cellular membrane, affording the
appearances from which the names are taken.
In confluent Small Pox and Cynanche Maligna, the
former attended with black pustules, blisters of dark
serum, petechiæ, and subsultus, the latter with deep
ulcers in the throat, the fauces, tongue, and roof
of the mouth covered with a black fordes, constant
diarrhœa and violent phrenitis, Dr. Dobson tells us that
complete relief was procured in a short time by carbonic
acid disengaged in the stomach by a mixture of 1 and
2 scruples of mild vegetable alkali and 1-2 an ounce
or an ounce of lemon juice, and this repeated every two
or three hours.
When this treatment is required in children who
cannot be made to take the mixture, the air may
readily be thrown up by clyster, or the child may be
held over an effervescing mixture for some length of
time, permitting it to be inhaled occasionally.
In Dyspepsia, when attended with considerable
anorexia, nausea, and eructation, we have well attested
proof of carbonic acid being found highly serviceable;
and this must be, without doubt, effected by the
gratefully stimulating gas imparting that tone to the
stomach, which renders it capable of executing its
allotted functions.
In the nausea and vomiting, that distressing symptom
of fever, so perplexing to physicians and discouraging 

44
to patients, the saline effervescing mixture first
recommended by Riverius has always been extolled
among the most serviceable, if not as the most effectual
of all medecines stiled antiemetics.
But here it may be asked if carbonic acid be a stimu-
lant, how can it by that property check a vomiting,
which must depend on too great a degree of irritation
already seated in the stomach? In answer to this, I
would first observe, that vomiting does not unfre-
quently depend on a debility, or want of power in the
stomach to perform its proper office; and then its
operation in the way suggested, will be sufficiently
evident. But when the vomiting is excited by irrita-
tion, as I believe it generally is, the explanation must
be considerably modified.
Daily experience evinces that substances acknow-
ledged as stimulants, produce the same effects with
carbonic acid, when used to relieve vomiting. It is
well known that ardent spirits and opium, will relieve
even the vomiting excited by tart. antimony, and we all
believe them to be truly stimulant. The fact may, I
think, be explained in two ways, either of which will
be deemed sufficient. With Mr. J. Hunter, we may
say that a new action is instituted by the carbonic acid,
different from, and more salutary than that previously
excited by the tart. antimony, or any similar cause.
We may likewise explain it by believing, that the new
stimulus determines the increased action or excitement,
from that part of the stomach in which it was first
seated, to another less irritable, and less intimately
connected with the other parts of the body ; from the
cardia, for instance, in which it may produce vomiting,
to the pilorus, in which the opposite effect would be
most likely to follow. On the same principle we
observe that a blister applied to the skin, during the
violent pains that fly through the different parts of the
body in inflammatory fever, give almost certain relief,
by inviting the determination of the action to, and as
it were, concentrating it in the skin, a part less sensible
and less immediately connected with life, than the

45
arterial system. The first of these, perhaps, will most
generally be received ; but I acknowledge that I can
not conceive of one muscular fibre being capable of
taking on so many different kinds or forms of contrac-
tion, (by which action must be effected) as the sup-
porters of this opinion contend for; and therefore
prefer the latter of the two opinions.
Dr. Percival recommends the exhibition of carbonic
acid in sea-scurvy, schrophula, and in dropsy*. It is
probably on this principle, that wort has been found
of evident service in many scorbutic and schrophulous
cases. The wort being a saccharine fluid, immediately
enters into a state of fermentation, and disengages the
acid.
In phthisis, carbonic acid inhaled into the lungs has
been proved, by the industry and perseverance of Dr.
Beddoes, and his friends, to be very powerfully effica-
cious in relieving the symptoms, and even perfecting
the cure, if sufficiently diluted with atmospheric air,
and inspired for a certain length of time each day.
The Doctor explains its beneficial agency in these
cases, as arising simply from the abstraction or dimi-
nution of oxigene in the air respired. This explanation
is in part, I believe just; for he has likewise shown,
that hydrogene and azote, when thus inspired, pro-
duced similar effects, which could only be from with-
holding oxigene, as they of themselves have no inhe-
rent action. But if it be found that carbonic acid
applied to old ulcers, gives them a disposition to heal
by stimulating the adjoining parts; and if it be believed
that the ulcers of the lungs are of this dull and languid
kind, from the nature of its substance; it will appear
probable that carbonic acid is likewise beneficial, by
* It was observed uniformly in all my experiments with this acid
taken into the body, that a great difcharge of urine always took
place: in a very short space of time, more than twice the quantity
of fluid drank would be returned; from which circumstance, I
suppose the impregnated water at least a very useful drink in cases of
dropsy. 

46
stimulating these ulcerated parts, and giving them a
healthy degree of action.
In cases of affection from calculi, the exhibition of
carbonic acid has been found so certainly beneficial, as
to demand the most serious attention. In a case of this
kind that came under my notice, the acidulous waters
of Saratoga have produced such effects as to leave no
doubt of their efficacy.
Mr. N. B. a respectable inhabitant of this city, had
been afflicted with the stone for the space of 36 years,
towards the last of which time, it was so troublesome
as to oblige him to have his urine discharged for two
months regularly, by means of a catheter; so violently
attacked was he at times, as to have his life despaired
of. With much difficulty he arrived at Saratoga, and
on using the water as his constant and only drink, at
the end of three weeks he was so perfectly restored, as
to have no further symptoms of his being ever distressed.
He continued thus free from every uneasiness for two
years, at the end of which time he had one slight
attack, which came on during the time of an inflam-
matory fever. It is now three years since the time of
using the waters, and he has never had but the one
return of his complaint. Even this appears probably
to have been a symptom of strangury, as a violent
affection of his stomach took place as it abated. The
Gentleman informed me that he drank the water
in the quantity of gallons per day*.
From the experiments of Dr. Percival, we find that
calculi are certainly dissolved in water thus impreg-
nated; and from the experiment of Dr. Dobson, it is
* In the Medical Memoirs, Vol. I. p. 225, a case is related of
Mr. John Hobman, in whom a stone was felt in drawing off his
water with a catheter. He took twice a-day, with diluted vitriolic
acid, a solution of salt of tartar highly srturated with carbonic acid,
and after three weeks voided a great quantity of urine with a fine
calculous matter; from which time he was freed from every symp-
tom of the affection. He died about five years after, and being
examined no remains whatever of calculous matter could be disco-
vered, 

47
proved that the urine of persons using the carbonic
acid is largely impregnated with it; for from fresh
urine of this kind, he procured 1-5th of its whole bulk
in carbonic acid. Dr. Percival likewise informs us,
that calculi infused in the urine of such persons, lost
in weight or was in part dissolved, while the same
in common urine increased in weight. If these circum-
stances come well attested, as they surely do, we can
no longer doubt of carbonic acid being a solvent for
the stone, and that it will not only relieve the symptoms,
but actually remove the cause.
That carbonic acid would be very effectual in melan-
cholia and depressions of the mind, we may reasonably
conclude from its acting specifically on the brain. That
this specific determination does take place, we have
not only proofs from every experiment, but see it
finely illustrated in the peculiar effects produced by
Champagne wine on the mind. To what of its com-
ponent parts, or which of them combined, can this
effect be ascribed, unless to the carbonic acid ? as we
know that other wines with the same or a greater
proportion of alcohol, with the same or a greater
proportion of must or saccharine matter, and with the
same proportion of other ingredients, will not produce
effects by any means similar *.
It has been found that frogs, fish, and insects of
their nature, will not live in water impregnated with
carbonic acid; from which I would conclude, that
drinks thus impregnated will prove of singular service
in removing worms from the alimentary canal. I have
been confirmed in this opinion by having observed that,
in this city, and N. York, where the chief drink of the
inhabitants is beer and porter; the children are much
less commonly afflicted with worms, than in the southern
states, where the inhabitants drink spiritous liquors in
common, and employ but inconsiderable quantities of
* May not an excellent Champagne be readily prepared at any
time, by impregnating a wine of the same apparent strength, &c.
with carbonic acid, by means of Nooth's apparatus.

48
malted drinks. Worms are found to exist in those
children especially, whose powers of digestion are
most feeble; and are supposed to act as assistants in
that process, till by their numbers or bulk, they
produce uneasiness. Porter, beer, and ale, it is pro-
bable, will, by the tonic property of their bitter, pro-
mote an increased vigour of the stomach, while it
destroys, by its carbonic air, the worms found in
these passages.
Dr. Dobson has published many extraordinary
instances of speedy cures being produced in long stand-
ing ulcers by the application of carbonic acid. In
ulcers of the fauces, he effected the most immediate
relief by giving the effervescing mixture, and by
fumigating the part with carbonic air disengaged from
chalk by vitrolic acid; it was even successful in a cawe
attended with caries. Dr. Percival has likewise given
cases of the same kind to prove its useful tendency; of
these he describes one of a painful apthous ulcer, and
recommends it in ulcerous sore throats.
Many cases are given by Dr. Beddoes which prove
the efficacy of carbonic acid, not only in curing old and
chronic ulcers, but likewise in putting a stop to gangrene,
in relieving schrophulous ulcers and tumors, and even
in checking the dreadful career of cancer and disarming
it of its power. Carbonic acid in these cases is by no
means a new remedy; its efficacy in the form of the
yeast poultice has been long known and confirmed by
frequent experience, before the principle was under-
stood, on which the yeast acted *. Dr. Beddoes
accounts for its beneficial effects in these cases, simply
by the exclusion of oxigene; but this cannot be satis-
factory, as the influence of oxigene may as effectually
be excluded by other means as this. If we reflect
that cancers are relieved, gangrene stopped, and
* Yeast has lately been recommended as an excellent cosmetic,
o remove the troublesome pimples that so commonly appear in the
face. See Beddoes on Factitious Air, p. 146. 

49
chronic ulcers cured by the application of stimulating
remedies alone; and if we remember that a property
of this kind is most conspicuous in the operation of
carbonic acid, we cannot be at a loss in explaining its
operation from the influence of this principle. Car-
bone or charcoal, the base of this gaseous fluid, has
lately been strongly recommended in gangrene, in
schrophula, and fœtid ulcers, by Drs. W. Sandford,
and John Johnstone, as published by Dr. Beddoes*;
it promises, I think, to be a valuable remedy.
Much have I to regret, that the short time limited
for preparing the matter of this dissertation, would not
admit of my inquiring more minutely into the uses of
carbonic acid, as a remedy for the afflictions of man;
and into the comparative efficacy of the several pro-
posed methods for relieving its bainful effects. Much
remains to be done in this important branch of medi-
cal inquiry ; for the great object of all our efforts is,
and ever should be, the improvement of that science,
which studies the prevention and cure of the many
diseases to which mankind is subject.
The uses ascribed to carbonic acid, in the several
affections above recited, are not simply the suggestions
of visionary speculation; they are advanced as effica-
cious by the most plausible reasoning, supported by
the strictest analogy, and confirmed by the most careful,
accurate, and unbiassed experience.
To the much admired Medical Professors in this
University, I am now thus publicly to offer my warmest,
and most unfeigned professions of gratitude for the
many favours, and the numerous instances of friend-
ship which I have experienced in private. In public,
your valuable lectures, from which I have derived the
common benefit with my associates, must ever be
* See Factitious Air, p. 126, &c. I have taken, at different
times, charcoal in fine powder to the quantity of ʒ ii. My stomach
being much afflicted with dyspepsia, I always found that it put a
certain stop to the disagreeable acid eructations and cardialgia.
G 

50
regarded as the great field from which I have reaped
my present stock of professional knowledge.
To be particularly grateful to either, would be
acting unjustly by the remainder—for you have all with
paternal advice, and laudable precept, directed my
pursuits, encouraged my labours, and promoted my
advancement in the acquisition of truth. Long may
you continue to receive the grateful acknowledgments
of your pupils, and to be regarded as their respected
Instructors, while you remain the Patrons of Industry,
and the Promoters of Medical Science.
THE END.