DR. MARSHALL HALL ON HYBERNATION. 
339 
On January the 28th, the temperature of the atmosphere being 42°, I placed 
a bat in the most perfect state of hybernation and undisturbed quiet, in the 
pneumatometer, during the whole night, a space of ten hours, from l h 30 m 
to ll b 30 m . There was no perceptible absorption of gas. 
Having roused the animal a little, I replaced it in the pneumatometer, and 
continued to disturb it from time to time, by moving the apparatus. It con- 
tinued inactive, and between the hours of l h 20 m and 4 h , there was the absorp- 
tion of one cubic inch only of gas. 
Being much roused at four o’clock, and replaced in the pneumatometer, the 
bat now continued moving about incessantly ; in one hour, five cubic inches 
of gas had disappeared. It was then removed. A further absorption took 
place of '8 of a cubic inch of gas. 
Thus the same little animal, which, in a state of hybernation, passed ten 
hours without respiration, absorbed or converted 5 ‘8 cubic inches of oxygen 
gas into carbonic acid, in one hour, when in a state of activity. In an inter- 
mediate condition, it removed one cubic inch of oxygen in two hours and 
forty minutes. 
I repeated this experiment on February the 1 8th. A bat, in a state of per- 
fect hybernation, was placed in the pneumatometer, and remained in it during 
the space of twenty-four hours. There was now the indication of a very slight 
absorption of gas, not, however, amounting to a cubic inch. 
On February the 22nd, I repeated this experiment once more, continuing it 
during the space of sixty hours ; the thermometer descended gradually, but 
irregularly, from 41° to 38° ; the result is given in the subjoined Table. 
External 
Date. 
February 22 
11 P.M. . 
Temperature. 
o 
. 41 
Absorption. 
Duration 
h 
23 
1 1 A.M. . 
CD 
CO 
•8 . 
. 12 
11 P.M. . 
. 39| . 
. 75 . 
. 12 
24 
1 1 A.M. . 
. 38 . 
*5 . 
. 12 
11 P.M. . 
. 39 
. 75 . 
. 12 
25 
1 1 A.M. . 
. 38 
•6 . 
. 12 
3-4 
60 
