ALPINE MARMOT. . 79 
Strictly speaking/' says M. Buffon, ee these 
animals cannot he said to sleep during the winter ; 
it may be called rather a torpor, a stagnation of 
all the faculties. This torpor is produced by the 
congelation of their blood, which is naturally 
much colder than that of all other quadrupeds. 
The usual heat of man and other animals is about 
thirty degrees above congelation ; the heat of these 
is not above ten degrees. Their internal heat is 
seldom greater than that of the temperature of 
the air. This has been often tried by plunging the 
ball of the thermometer into the body of a living 1 
dormouse, and it never rose beyond its usual 
pitch in air, and sometimes it sunk above a degree. 
It is not surprising, therefore, that these animals, 
whose blood is so coid naturally, should become 
torpid, when the external cold is too powerful for 
the small quantity of heat in their bodies, yet re- 
maining; and this always happens when the ther- 
mometer is not more than ten degrees above com 
gelation-*’ This coldness M. Buffon has experi- 
enced in the blood of the bat, the dormouse, and 
the hedgehog, and with great justice he extends 
the analogy to the marmot, which, like the rest, 
is seen to sleep all the winter. This torpid state 
continues as long as the cause which produces it 
continues ; and it is very probable that it might 
be lengthened out beyond its usual term, by artifi - 
cially prolonging the cold ; if, for instance, the 
animal were rolled up in wool, and placed in a 
cold cellar, nearly approaching to, but not quite 
so cold as an ice-house, for that would kill them 
outright, it would remain perhaps a whole year in 
its state of insensibility. However this be, if the 
heat of the air be above ten degrees, these animals 
are seen to revive : and, if it be continued in that 
degree of temperature, they do not become torpids 
