56 PHILOSOPHY OF ZOOLOGY. 



and recovered perfectly on being placed in a warmer me- 

 dium. 



In the exhausted receiver of an air-pump, a torpid bat 

 lived seven minutes, in which another bat died at the end 

 of three minutes. Torpid bats, when confined in a vessel 

 containing atmospheric air, consumed six hundredths of 

 the oxygen, and produced five hundred parts of carbonic 

 acid. Viewing this in connection with his other experi- 

 ments, this philosopher concluded, that the consumption of 

 the oxygen, and the evolution of the carbonic acid, pro- 

 ceeded from the skin. 



The respiration of torpid quadrupeds is thus greatly di- 

 minished, and even in some cases suspended ; and in gene- 

 ral, instead of being performed with regularity as in ordi- 

 nary sleep, the respirations take place at intervals, more or 

 less remote, according to the condition of the lethargy. 



3. Diminished Circulatimi. — From the experiments al- 

 ready detailed, with regard to the reduction of the tempe- 

 rature and the respiration of torpid quadrupeds, we are 

 prepared to expect a corresponding diminution of action in 

 the heart and arteries. 



In the hamster the circulation of the blood during its 

 torpid state is so low, according to Buffon, that the 

 pulsations of the heart do not exceed fifteen in a minute. 

 In its active and healthy state, they amount to 150 in the 

 same space. 



It is stated by Barrington in his Miscellanies, that 

 Mr Cornish applied a thermometer to the body of a 

 torpid bat, and found that it indicated 36°. At this tem- 

 perature the heart gave sixty pulsations in a minute. When 

 awakened so much as to be able to fly a little, he again ap- 

 plied the thermometer, which now indicated 38", and the 

 heart beat one hundred times in a minute. As the torpor 

 becomes profound, the action of the heart is so feeble, that 



