ANIMAL HEAT. 107 



where the experiments are conducted with any 

 degree of care, is certainly but trifling, and not 

 such as will account for the great diminution of 

 temperature which takes place. In confirmation 

 of what is now stated, I may refer to the follow- 

 ing experiment made by Dr. Chossat.* Having 

 perforated the cranium of a dog, by means of a 

 small trephine, he made a section of the brain im- 

 mediately in front of the Pons Varolii, so as to 

 intercept the communication of the nervous in- 

 fluence from the rest of the brain to the last men- 

 tioned organ. The animal continued to breathe 

 by his natural efforts, the pulse and respiration 

 being for many hours as frequent as under ordi- 

 nary circumstances. Nevertheless at the end of 

 four hours he had lost 9*7 (centigrade) of heat ; 

 while, in another experiment, a dog, a very 

 little larger, which had been killed by the divi- 

 sion of the spinal chord in the upper part of the 

 neck, lost 8*8 (centigrade) in the same period 

 of time. It may be further observed, that my 

 experiments were all made during the warm wea- 

 ther of summer, when the cooling property of 

 the air must have been much less than in the 

 cold season of the year, and that, whatever might 

 have been the influence in this respect of the 

 artificial respiration in my first series of experi- 

 ments, it must have been very trifling in my 

 second series, not only because, these last experi- 



* Memoire sur Tlnfluence du Systeme Nerveux sur la 

 Chaleur Animate, p. 15. 1820. 



