3B8 Mr. Brodie’s Experiments and Observations 
The air being examined, was found to contain T r ¥ of carbonic 
acid. 
The rabbit occupied the space of 47 cubic inches. 
L c T±if. 1: 2 ~ 1? — 022 — 28.275 cubic inches of carbonic acid 
18 18 
evolved in 30 minutes, which is at the rate of 56.55 cubic inches 
in an hour. 
The animal lay as if in a state of profound sleep. At the 
end of two hours and twenty minutes, from the time of the 
poison being applied, the thermometer in the rectum had fallen 
to 79 0 , and he was again apparently dead ; but the heart still 
continued acting, though feebly, and its action was kept up for 
30 minutes longer by means of artificial breathing, when the 
thermometer had fallen to 76°. The carbonic acid evolved 
during these last 30 minutes, amounted to nearly 13. cubic 
inches. 
From the precautions with which these experiments were 
made, I am induced to hope that there can be no material 
error in their results. They appear to warrant the conclusion, 
that in an animal in which the brain has ceased to exercise its 
functions, although respiration continues to be performed, and 
the circulation of the blood is kept up to the natural standard, 
although the usual changes in the sensible qualities of the 
blood take place in the two capillary systems, and the same 
quantity of carbonic acid is formed as under ordinary circum- 
stances ; no heat is generated, and (in consequence of the cold 
air thrown into the lungs) the animal cools more rapidly than 
one which is actually dead. 
It is a circumstance deserving of notice, that so large a 
