on muscular Motion, 
The hybernating animals require a longer time in drowning 
than others. A full grown hedge-hog was submersed in water 
at 48°, and firmly retained there ; air-bubbles began instantly 
to ascend, and continued during four minutes ; the animal was 
not yet anxious for its liberty. After seven minutes it began 
to look about, attempting to escape ; at ten minutes it rolled 
itself up, only protruding the snout, which was hastily re- 
tracted on being touched with the finger, and even the approach 
of the finger caused it to retract. After fifteen minutes com- 
plete submersion, the animal still remained rolled up, and 
withdrew its nose on being touched. After remaining thirty 
minutes under water, the animal was laid upon flannel, in an 
atmosphere of 6e°, with its head inclined downwards ; it soon 
began to relax the sphincter muscle which contracts the skin, 
slow respirations commenced, and it recovered entirely, without 
artificial aid, after two hours. Another hedge-hog submersed 
in water at 94 0 , remained quiet until after five minutes ; about 
the eighth minute it stretched itself out, and expired at the 
tenth. It remained relaxed, and extended, after the cessation 
of the vital functions ; and its muscles were relaxed, contrary 
to those of the animal drowned in the colder water. 
The irritability of the heart is inseparably connected with 
respiration. Whenever the inhaled gas differs in its properties 
from the common atmosphere, the muscular and sensible parts 
of the system exhibit the change : the actions of the heart are 
altered or suspended, and the whole muscular and sensorial 
systems partake of the disorder : the temperature of animals, 
as before intimated, seems altogether dependant on the respi- 
ratory functions, although it still remains uncertain in what 
manner this is effected. 
D 2 
