1821.] Influence of the Nervous System on Animal Heat. 37 



Article VI. 



Extract of a Memoir on the Influence of the Nervous System oh 

 Animal Heat.* By Dr. C'hossat. 



Mr. Brodie, in his important researches on the Influence of 

 the Brain on the Action of the Heart and Animal Heat, has 

 shown, first, that after decapitation the animal heat diminishes 

 several degrees in one hour, notwithstanding the artificial infla- 

 tion of the lungs ; and, secondly, that the animals decapitated 

 and inflated cool more rapidly than those killed merely by the 

 section of the spinal marrow under the occiput ; and thus, after 

 decapitation, no perceptible quantity of heat is produced. I 

 propose in this paper to analyze these important results, and in- 

 quire in what manner the nervous system can influence the pro- 

 duction of animal heat. 



As preliminaries, I shall mention some considerations neces- 

 sary for the better understanding of the facts afterwards to be 

 related ; viz. 



1. The Phenomena of Death by Cold, — In a great number of 

 experiments made with my friend Dr. Prevost, (yet unpublished) 

 we have seen in dogsf placed in the cold bath, death take place 

 at 20'° centigr., and below this point in proportion to the slow- 

 ness of the refrigeration of the body. At the autopsy we have 

 found a nearly total extinction of muscular irritability and peris- 

 taltic motion, blood, commonly arterial, in the lungs and aorta, 

 and some serum in the ventricle of the brain. 



2. The Progress of Refrigeration after Death. — I propose to 

 compare this refrigeration with that which happens after the 

 wounds inflicted on the nerves, in order to determine the in- 

 fluence of this system in the production of animal heat. 



Exper. I. — In an animal which died from syncope soon after 

 the section of the spinal marrow, the initial temperature being 

 at the moment of death 40-5°, I found that 



From 40-0° to reach 31-7 3 1 ' 30' were employed. 



31-7 23-9 .... 7 



Dividing the number of degrees by that of the hours employed, 

 we obtain, what I shall call hereafter, the average refrigera- 

 tion, i. e. the average diminution of animal heat in one hour be- 

 tween such limits as we think proper to choose. Adopting the 



• Presented to the Academy of Sciences on May 1 5, 1 S20. An extract of this paper 

 has already appeared in the Annates de Chimic ctile Physique, from which the present 

 article was translated, with some variations and additions, by the author, during his 

 late residence in London. — Ed. 



+ All the experiments related in this paper have been performed on dogs. 



