temperature of the skin 45. It seems, therefore, 

 clearly demonstrated, that in torpidity the tempera- 

 ture of the body is reduced. 



II. In the case of the mus cricetus, when active and 

 irritated, its heart beats 150 strokes in a minute ; 

 while in a torpid state the number of pulsations are 

 reduced to 15. In the bat, the number of beats may 

 be stated at 100, but when torpid these amount to 

 only about 14-. Dormice have a very rapid pulse; but 

 when semi-torpid, the number of beats may be con- 

 sidered about 31. The action of the heart ultimately 

 becomes imperceptible, and before this period the 

 pulsations do not exceed 16. It is not probable, that 

 though the circulation be reduced to its lowest pulse, 

 and the diastole and systole become inappreciable, that 

 the blood ever congeals, though it may become more 

 dense. Spallanzani informs us, that if the abstracted 

 blood of the marmot be subjected to a temperature 

 even higher than that of the lungs of the animal, it is 

 frozen, but is never found congealed in their torpid state, 

 even after exposure to a cold several degrees below 

 the zero of Fahrenheit : so true is it, that " in the 

 blood is the life thereof." These facts show plainly, 

 that though the circulation be in a state of torpidity, 

 and reduced to its minimum, that agency, superadded 

 to their material organisation, which we call the prin- 

 ciple of life, preserves the circulating fluid in a liquid 

 form. 



III. By the experiments of Spallanzani, torpid bats 

 lived seven minutes in the exhausted receiver of an 

 air-pump, in which another bat perished in less than 

 one half this period. Some animals will support such 

 an attenuated medium for a long period : we found 

 this in experiments, with the grasshopper: the respir- 

 ation seemed hurried and laborious, but it was not in- 



