qs 
in his third lecture at the Royal Institu- 
tion ; because, we conceive they are not 
supported by the experiments which 
have been made in this country, and 
those very recently made in France, te- 
Jating to respiration and animal heat. 
Dr. Davy stated, that he believed ani- 
mal heat was not produced by the abe 
sorption of oxygen, in the act of respira- 
tion, as Crawford had supposed; but, 
» that it was the result of all the changes 
and organic actions which’ were taking 
place in living animal bodies. He said 
that Mr. Brodie had lately exhibited 
some experiments before the Royal So- 
ciety, in which the nerves connected 
with respiration, hed been destroyed, 
and life and circulation ‘continued, but 
anattended with the production of ani- 
mal heat. Whence'he inferred, that the 
iervous system was more necessary to 
its production than the sanguineous, or 
than respiration and circulation. Of the 
amanner in whith these experiments 
were conducted, we were not informed; 
tut, from what we have since learn- 
ed, we believe, that air was forced by 
@ pair of bellows into the lungs of a 
tabbit, after the nerves connected with 
‘the lungs had been cut. This experiment 
appears to us to have been improperly 
conducted, if it were intended to decide 
the cause of animal heat. A current of 
air blown into the lungs, might itself 
lower the temperature of the body. The 
experiments of the French fphilosophers 
appear less liable to objection, as a pas- 
sage was opened to the lungs, in order to 
admit access of air after the section of 
the nerves had been made. The respi- 
ration which had been suspended, re- 
sumed its action, accompanied with the 
usual change of the venous into arterial 
blood. These experirients we shall state 
here, as we believe no account of them 
has yet been published in this country. 
We shall introduce them with observing 
that Dr, Davy gave an account of the 
experiments of Dr. Fordyce and others, 
in which animals’ had been confined in 
rooms heated to more than 212 degrees, 
and, after remaining a considerable time, 
the temperature of the blood was. not 
raised more than two degrees. This et+ 
fect Dr. Davy attributed to the force of 
the vital principle controling the agency 
of material elements. 
“Dr. Franklin suspected that the ex- 
planation of this fact must be sought an 
the increased perspiration whieh the heat 
‘occasions, it being’ an ackuowledged 
Proceedings of Learned Societies, 
[Maro 45 
principle, that evaporation df every kind | 
produces cold. M. De Laroche the 
Younger, published some experiments, 
made in common with Mr. eteary in 
which, these two philosophers observed 
a very sensible augmentation of heat 
in animals exposed to a high temperay 
ture, in atmospheres of sufficient humi- 
dity to prevent. the transpiration, of 
moisture both from the skin and the 
lungs.. He stated, that animals, under 
such circumstances, increase in heat toa 
certain point, beyond the medium degree 
of their own natural temperature, and 
the temperature of the room in which 
they are inclosed, because the heat pro- 
duced by their !respiration, 1s added te 
that of the atmospbere which surrounds 
them. He has thus refuted a chimerical 
property attributed to the vital princie 
ple, and has proved that the illusion 
arises. solely from the cause suspected 
by Franklin.” , ' 
M. Depuytren, a little time since, made 
experiinents, which appear, in some dex 
gree, to sanction the conclusions of Dr,. 
Davy, from similar experiments of Mr, 
Brodie, which we have stated... These 
experiments consisted in cutting the 
eighteenth pair of nerves which go to the 
larynx, the lungs, the heart, and the 
stomach, As soon as the section was 
made, the animal began to languish and 
die, and the blood ceased to acquire the 
arterial quality in its passage through the 
Jungs, although the necessary functions 
of respiration were not deranged in a 
degree proportionate to such an effect, 
Mr. Blainville has taken up the subject, 
and opposed the conclusions of Mr. Dur 
puytren; he has observed, after the sec- 
tion of the same pair of nerves, deranges 
ments in the functions of the stomach, 
which have contributed as much to the 
death of the animal, as the derange. 
ments of the pulmonary functions.. He 
has even decided, after these experiments, 
that there js no..interruption in the 
change of the venous into arterial blood, 
M. Dumas, professor at Montpellier, 
having opened a passage for the air to 
the lungs f those animals, which had 
suffered the operation. of. cutting the 
nerves, has seen that respiration res 
sumes its action upon the blood. It ig 
prover! by a variety of other experiments, 
(of which an account Is given in the re+ 
port of the National Institure,)that,when 
this operation is performed, and there is 
venous blood, the animal has experi. 
enced suffycation from a sudden con- 
, ia strictiog 
