BOOK by that expedient, it was awakened from its lethargy, took a few
- — i turns about the room, and eat a few morfels; but foon lay down
againr and palled its torpid months as nature ordains.
It is probable, that the bodies of thefe animals, who fleep
during winter, are gradually prepared for the torpid ftate by a
\ deficiency of food, and a conlequent diminution of natural heat j
for, a thermometer plunged in the bellies of marmots and hedgehogs
in their natural ftates, rofe to 76, 79, 81, 86, 88, 99, and
99I, namely, from 361 degrees to 50 higher than it rofe when
plunged into the belly of the hedge-hog in its torpid Rate.
The following fa£t alfo feems ftill further to illuftrate the con-
jedture, that a certain ftate of body predifpofes to a torpid ftate.
A tame marmot, which had become extremely fat during fummer
in the profeffor’s houfe, continued awake during the whole winter1,
although it was expoled to the lame cold which threw the whole
fpecies into their torpid ftate in that part of Siberia; nor was
the doftor able to render it torpid, even with the afilftance of
the ice-cellar, wherein he fometimes confined it during feveral
days.
By comparing this experiment with the lleeping hedge-hog,
which Dr. Pallas was not able to roufe from its lethargy during
the whole winter, except for very ihort intervals, though ex-
pofed to a heat of between 77 and 80 degrees; it feems to follow,
that a certain ftate of body is necellary to affift nature in
laying alleep fome animals, to which they are gradually brought
by a deficiency’ of nourilhment about the beginning of winter,
when
when they ihut up their holes, and retire to reft from inftindt; c h a p .
and that the impulfe of the circulation and animal fpirits, arifing .
from heat or full feeding, fuperfedes the neceffity of the torpid
ftate, and prevents their falling alleep.
It is alfo a curious circumftance in the ceconomy of nature*
that Dr. Pallas found the heat of birds more confiderable than
that of quadrupedes; namely, from 103 to 111 degrees; a wile arrangement
of providence in proportioning the heat of the winged
tribe to the fuperior cold obtaining in that part of the atrtio-
fphere where they range.
L 1 a C H A P .