THE PURIFICATION OF THE BLOOD, ETC. 47 



energy. When the human body (or that of 

 any warm-blooded animal) is subjected to 

 cold, its temperature immediately sinks, but 

 after the shock it rises by the agency of an 

 innate force. Dr. Currie ascertained, (Phil. 

 Trans., 1775, p. 121,) that the heat of the 

 human body in one instance sank rapidly from 

 98° to 87° when placed in water at 44°, but at 

 the end of twelve minutes it rose to 93°. In 

 another experiment in water of the l*me 

 temperature, the heat of the body fell from 98°, 

 in the course of two minutes to 88°, but at the 

 end of thirteen minutes had risen to 90°. " Dr. 

 Hunter found that a dormouse, whose heat in 

 an atmosphere of 64° was 811°, when put into 

 air. at 20° had its temperature raised in the 

 course of half-an-hour to 93° ; an hour after- 

 wards, the air being 30°, it was still 93° ; at 

 another hour afterwards, the air being 1 9°, the 

 heat of the pelvis was as low as 83°, but the 

 animal was now less lively. In this experiment 

 the dormouse had maintained its temperature 

 about 70° higher than the surrounding medium, 

 and for the space of two hours and a half." In 

 cold-blooded animals, heat is generated under 

 similar circumstances. Hunter found that the 

 heat of a viper placed in a vessel at the tem- 

 perature of 10°, sank in the course of ten 

 minutes to 37° ; but in the course of ten 

 minutes more, the temperature of the vessel 

 being 13°, its temperature was 35°; in the next 

 ten minutes, the vessel being at 20°, that of the 

 reptile was 31°. In the case of frogs, he was 



