DR. MARSHALL HALL ON HYBERNATION. 
357 
an hour, and then the thermometer was introduced as before ; but the animal 
had lost heat, for the quicksilver at the diaphragm was carried only to 83°, 
in the pelvis to 78°.” 
“ In order to determine whether an animal that is awakened has the same 
powers, with respect to preserving heat and cold, as one that is vigorous and 
strong, I weakened a mouse by fasting, and then introduced the bulb of the 
thermometer into its belly ; the bulb being at the diaphragm, the quicksilver 
rose to 97° ; in the pelvis to 95°, being two degrees colder than the strong- 
mouse : the mouse being put into an atmosphere as cold as the other, and the 
thermometer again introduced, the quicksilver stood at 79° at the diaphragm, 
and at 7 4° in the pelvis. 
“ In this experiment, the heat at the diaphragm was diminished 18°, in the 
pelvis 21°. 
“ This greater diminution of heat in the second than in the first, we may sup- 
pose proportional to the decreased power of the animal, arising from want 
of food*.” 
But extreme cold alone, by a painful effect induced on the sentient nerves, 
rouses the hybernating animal from its lethargy, as has been remarked already, 
and is illustrated by the following experiments of Hunter. Having brought 
a healthy dormouse, which had been asleep from the coldness of the atmo- 
sphere, into a room in which there was a fire, (the atmosphere at 64°,) I intro- 
duced the thermometer into its belly, nearly at the middle, between the thorax 
and pubis, and the quicksilver rose to 74° or 75°; turning the bulb towards 
the diaphragm, it rose to 80° ; and when I applied it to the liver, it rose to 81§°. 
<e The mouse being placed in an atmosphere at 20°, and left there half an 
hour, when taken out was very lively, even much more so than when put in. 
Introducing the thermometer into the lower part of the belly, the quick- 
silver rose to 91° ; and upon turning it up to the liver, to 93°. 
“ The animal being replaced in the cold atmosphere at 30°, for an hour, the 
thermometer was again introduced into the belly ; at the liver it rose to 93° ; 
in the pelvis to 92° ; the mouse continuing very lively. 
“ It was again put back into an atmosphere cooled to 19°, and left there an 
* Animal (Economy, pp. 114, 115. 
MDCCCXXXII. 3 A 
