138 
This reasoning is perhaps more specious 
than just. In the first place, the remarks 
which we have above introduced on the actual 
diminution of febrile heat from inhaling an 
oxygenous atmosphere, seem to oppose the 
theory of refrigeration, from “ less of the 
oxygenous principle being consumed in the 
lungs.” Secondly, it may be noticed that 
the effects of these medicines are too speedy 
and direct to admit of the supposition of this 
intermediate kind of agency; and thirdly, 
although the refrigerantia are for the most 
pait, they are not universally, substances 
which contain this suberabundance of the 
oxygenous principle. The saline draught, 
MEDICINE, 
for example, appears to moderate febrile 
heat, principally by reason of the carbonic 
acid gas that it contains. 
Chemical reasoning has recently been ex- 
tensively applied to the developement of the 
mode in general in which the functions of 
the stomach and lungs are connected, and as 
this enquiry is closely related both to the 
theory of febrile heat, and the dietetical as 
-well as the medicinal management of the 
febrile invalid, it may not be improper to 
detain the reader by one or two further re- 
flections on this very interesting point of 
discussion. It is an axiom of Hippocrates, 
that animal food should not be given in fever ; 
an axiom which was no doubt founded upon 
observation of its general irritating and dis- 
ordering tendency. Modern physiology, 
however, has not rested content with a know- 
ledge of the fact, but has endeavoured to 
divine its immediate cause. That digestion 
of the food is, caeteris paribus, in proportion 
to the oxygenation of the blood; or to avoid 
an expression involving theory, to the purity 
of air and freedom of inspiration, which an 
individual enjoys, is without question ; and 
it is further evident from daily observation, 
.that the facility of assimilating animal food, in 
particular, is increased by air, exercise, and 
whatever promotes an uninterrupted circu- 
lation through the pulmonary organs. Hence 
it is said, we are furnished with an expla- 
nation why animal diet is uncongenial to the 
patient in fever. T he pulmonary circulation 
is impeded by febrile oppression, less oxy- 
gen is received from the atmosphere, and the 
power of assimilating materials which contain 
the hydrogenous and azotic principles in 
abundance is consequently weakened, or, as 
we have heard it expressed still more che- 
mically, less fuel or combustible matter is 
required, on account of there being less 
power of consuming such fuel, or of main- 
taining combustion. 
Perhaps the peculiarity or distinct nature 
of living action, has not been sufficiently at- 
tended to by modern physiologists of the 
chemical school. That hypothesis, the out- 
line of which we have just delineated, appears 
at first sight perspicuous and unobjection- 
able, but when pursued more in detail, facts 
present themselves which are in some mea- 
sure at variance with its fundamental prin- 
ciples. 
Animal food may, perhaps, prove less con- 
genial to the patient in fever, than under cir- 
cumstances of debility without febrile dis- 
turbance, on account of the direct irritation 
it com muni cat s to the fibre, independantiy 
of its chemical properties ; the difference be- 
tween animal and vegetable diet in this 
particular, is abundantly obvious. But it 
may further be urged, that several materials 
taken into the stomach during tire burning 
heat of fever, appear to be productive ol 
nearly similar effects, in their immediate 
operation, with a diet of animal food ; of this 
we have an instance in opium. Opium, 
which when duly administered is congenial 
and salutary, when given while the skin is 
dry, and there is no disposition to perspi- 
ration, proves irritating and hurtful ; it still 
further impedes the weakened digestive 
organs, augments the tendency to costive- 
ness, and increases febrile heat. These pro- 
perties it surely does not possess by virtue 
of the quantity of hydrogen or 
contains. 
Of Sudor ifics. 
We now proceed to consider the agency 
of sudorifics as febrifuge remedies. Moisture 
on the surface of the body may be procured 
by medicines which appear to have a direct 
power over the cutaneous vessels, or by 
those whose action seems to be directed pri- 
marily to the stomach. These last are prin- 
cipally of the saline class, which are by far 
the most suitable in the febrile state. 
The physiology of perspiration, and the 
principles "by which it operates as a cooling 
process, are, notwithstanding the recent dis- 
coveries in chemistry, and their application 
to this interesting subject, still involved in 
much obscurity. 
The ancients imagined sweat to be not 
merely an excrementitious product, but the 
vehicle of conveying that morbific matter 
out of the body which had been the occa- 
sion of disease, i his opinion does not, in 
the present state of science, require to be 
confuted. The questions of most interest, 
respecting tin; phenomena and causes of 
perspiration, are, in what relation does it 
stand to the respiratory function ; and is that 
moisture on the surface ot the skin which 
closes a febrile paroxysm, to be regarded as 
a cause or consequence of the disorder’s de- 
clination ? 
“ That an animal,” says Dr. Currie, 
“ possesses to a certain extent the faculty 
of rendering sensible heat latent, or, to speak 
more philosophically, of reducing caloric 
from a free to a combined slate, in cases in 
which the stimulus of heat might otherwise 
overpower the living energy, there is reason 
to believe, from a variety ot experiments and 
observations; and that this is in part per- 
formed by perspiration from the surface can 
scarcely admit of a doubt. The process of 
perspiration, which is continually going on 
from the surface ot the body, is in this point 
of view the converse of respiration; as in 
respiration a gas is constantly converted into 
a solid or fluid, and thus heat evolved, so 
in perspiration a fluid is constantly converted 
into a vapour, and thus heat is absorbed. A 
vessel filled with water and exposed to the 
atmosphere, cannot be raised above 2i0° of 
Fahrenheit by any quantity of fuel, because, 
heat is applied from below, evaporation car- 
ries it off from the surface ; in like manner 
we may suppose the heat of the living body 
to be kept uniform, by the evaporation from 
its surface increasing or diminishing, accord- 
ing to the quantity of heat extricated from 
the system, or received from the surrounding 
medium.” 
These speculations are beautiful and 
highly ingenious, It however admits of 
question, whether Dr. Currie, in applying 
them to the subject of febrile heat, may not 
have given too much w eight to the analogy 
of absorption of caloric in inanimate matter, 
as explanatory ot the cooling process in the 
living body ; and whether sensible perspira- 
tion, produced by medicine or otherwise, 
may not be consequent upon, rather than 
prior to, the diminution of febrile heat? if, 
tor example, a large quantity of water be 
swallowed m the height of a febrile paroxysm, 
and be directly succeeded by general dia- 
| phoresis, or sweat, with relief lrom the 
; burning sensations of fever, although it be 
azote that it ! natural to attribute such relief to the sweat 
that is produced, this last may be subsequent 
to that altered condition of the hbre by 
which the evolution of caloric is dimi. ashed. 
Such an opinion lias been ingeniously 
argued by Dr. Reid ; and if the following 
observations ot Dr. Darwin are just, they 
appear to place the matter beyond dispute. 
“ The perspirable matter,” says this last au- 
thor, “ is secreted in as gieat quantity dur- 
ing the hot fit of fever, as towards the end 
of it, when the sweat is seen upon the skin. 
But during the hot fit, the cutaneous ab- 
sorbents act also with increased energy, and 
the exhalation is likewise increased by the 
greater heat of the skin ; and lienee it does 
not appear in drops upon tiie surface ; but 
is in part reabsorbed and in part dissipated 
in the atmosphere. But as the mouths of 
the cutaneous absorbents are exposed to the 
cool air or bed-clothes ; while those ol t he 
capillary glands, which secret the perspi- 
rable matter, are exposed to the warmth of 
the circulating blood ; the former, as soon 
as the fever fit begins to decline, lose their 
increased action first ; and hem e the ab- 
sorption of sweat is diminished, whilst the 
increased secretion of it continues for some 
hours afterwards, which occasions it to stand 
in drops upon the skin. As the skin be- 
comes cooler, the evaporation of the perspi- 
rable matter becomes less as well as the ab- 
sorption of it. And hence the dissipation of 
aqueous fluids from the body, and conse- 
quent thirst, are perhaps greater during the 
hot fit than during the subsequent sweat. 
For the sweats do not oc. ur, according to 
Dr. Alexander's experiments, till the skin 
is cooled from 112 to 108 degrees ot heat; 
that is, tiil the paroxysm begins to decline. 
From this it appears that the sweats are not 
critical to the hot fit, any more than the 
hot fit can be called critical to the cold one, 
but simply that they are the natural conse- 
quences of the decline ot the hot fit And 
from hence,” continues our author, “ it may 
be concluded, that a fever fit is not an effort 
of nature to restore health, but a necessary 
consequence of the previous torpor; and 
that the causes of fever would be less detri- 
mental, if the fever itself could be prevented 
from existing, as appears in the cool treat- 
ment of the small pox.” 
Of Purgatives and Emetics. 
Nothing, perhaps, is of greater moment 
in almost every stage and every kind of fe- 
ver, than to preserve the whole of the ali- 
mentary canal free from accumulations of 
colluvies, &e. From a deficient attention 
to tiiis principle, the medical practitioner is 
in many instances foiled in the treatment of 
this, and indeed in a variety of other dis- 
ease?. Viscidities and impurities in the sto- 
