on the Influence of the Brain, &c. 
3 35 
50 times in a minute. When this process had been continued 
for 30 minutes, a portion of air was preserved for examina- 
tion. The heart was found acting regularly, but slowly, the 
thermometer in the rectum had fallen to 90°. 
The second rabbit was killed by dividing the spinal marrow 
about the same time when the experiment was begun on the 
first rabbit. Being in the same temperature, the time was 
noted when the thermometer in the rectum had fallen to 97°, 
and it was placed under another bell-glass, that it might be 
as nearly as possible under the same circumstances with the 
first rabbit. At the end of 30 minutes, the thermometer in 
the rectum had fallen from 97 to 91.* 
The air respired by the first rabbit contained ~ of carbonic 
acid. The bulk of the rabbit was found = 50 cubic inches. 
20.24 cubic inches of carbonic acid were therefore extricated 
in 30 minutes, which is at the rate of 40.48 cubic inches in an 
hour. 
The carbonic acid given out in the same space of time 
was less than in the former experiments ; but it is to be ob- 
served, first, that in consequence of the ligatures the extent of 
the circulation was diminished ; secondly, that in this instance 
one of the ligatures accidentally slipped, and an ounce of blood 
was lost in the beginning of the experiment. 
As it was desirable to avoid any circumstances, which might 
occasion a difference in the results, in the subsequent experi- 
* In measuring the heat of the rectum in these experiments, care is necessary that 
the thermometer should always be introduced to exactly the same distance from the 
external parts, otherwise no positive conclusion can be drawn relative to the loss of 
heat, as the more internal parts retain their heat longer than the superficial. 
502 + 52 + 2 — 50 
506 
“ = 20.24, 
