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 in 
to ll l< 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 18th. 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. Temperature. Absorption. Duration. 
February 22 
11 
P.M. . 
. 41 
23 
11 
A.M. . 
• 38§ . . 
•8 . 
. 12 
11 
P.M. . 
. 391 . . 
75 . 
. 12 
24 
11 
A.M. . 
.38 
•5 . 
. 12 
11 
P.M. . 
.39 
75 . 
. 12 
25 
11 
A.M. . 
.38 
•6 . 
. 12 
3-4 
60 
