on the Action of the Heart, Se; 449 
dividing the spinal marrow between the occiput and atlas. 
In consequence of the difference of size, ceteris paribus, 
the heat in this rabbit ought to diminish more rapidly than 
in the other; and I therefore examined its temperature at 
the end of 53 minutes, considering that this would be at 
least equivalent to examining that of the larger rabbit at the 
end of an hour. At 52 minutes from the time of the 
smaller rabbit being killed, the heat among the viscera of 
the abdomen was 92°, and between the lobes of the right 
lune it was 91°. From this experiment, therefore, it ap- 
peared not only that no heat was generated in the rabbit, 
_in which the circulation was maintained by artificial respira- 
tion, but that it even cooled more rapidly than the dead 
rabbit. 
At the suggestion of professor Davy, who took an interest 
in the inquiry, I repeated the foregoing experiment on two 
animals, taking pains to procure them more nearly of the 
same size and colour. . 
Experiment 7.—I1 procured two large full grown rabbits, 
of the same colour, and so nearly equal in size, that no dif- 
ference could be detected by the eye. 
The temperature of the room was 57°, and the heat in the 
rectum of-each rabbit previous to the experiment was 1003. 
I divided the spinal marrow in one of them, produced 
artificial respiration, and removed the head after having se- 
cured the vessels in the neck. The artificial respirations 
were made about 35 times in a minute. ‘ 
During the first hour, the heart contracted 144 times in 
a minute. 
At the end of an bour and a quarter the pulse had fallen 
to 136 in a minute, and it continued the same at the end 
of an hour and a half. At the end of an hour and forty” 
minutes the pulse had fallen to 90 in a minute, and the 
artificial respiration was not continued after this period. — 
Half an hour after the spinal marrow was divided, the 
heat in the rectum had fallen to 97°. 
At 45 minutes the heat was 953. 
At the end of an hour the heat in the rectum was 94°. | 
At an hour and a quarter it was 92°. 
At an hour and a half it was 91°. 
At an hour and forty minutes, the heat in the rectum was 
g04, and in the thorax, within the hag of the pericardiuin, 
the heat was 874. 
The temperature of the room being the same, the second 
rabbit was killed by dividing the spinal marrow, and the 
temperature was examined at corresponding periods. 
Vol. 37. No, 158. June 1811. Ft Half 
