42 Dr. Chossat on the Lifiuence of [July, 



Maximum of refrigeration. 



Exper. 16 8th 



Exper. 17 9th 



Exper. 18. 10th 



Exper. 19 11th 



Exper. 20 12th 



I conclude : 



1. That animal heat diminishes, in general, more slowly 

 as the section has been performed lower down in intervertebral 

 space. It is to be remarked that the numbers which relate 

 to the eight superior of these spaces present a decreasing pro- 

 gression nearly regular. 



2. The diminution being the quicker as the section paralyses 

 a greater number of nerves, it is to this paralysis, and not to the 

 local affection of the spinal marrow (which is always the same in 

 every experiment) that the first phenomena must be attributed. 



• Now the dorsal part of the spinal marrow being in communi- 

 cation with no other nerves but the intercostals and the great 

 sympathetic ; as the distribution of the first, exclusively to the 

 external part of the chest, does not permit us to suppose them the 

 organs through which the nervous system acts on animal heat ; 

 the great sympathetic is therefore the only one which can furnish 

 us with a probable explanation of the phamomena. It was then 

 necessary to act upon this nerve. 



For this purpose, the best process seemed to me to extract the 

 capsula subrenals of the left side by means of an incision below the 

 13th rib. As the great sympathetic nerve adheres firmly to this 

 thin capsule, we are nearly certain of dividing it by this opera- 

 tion ; and even in case of our failing in it sometimes, the nerve 

 must necessarily be so much contused as greatly to debilitate its 

 functions. Therefore, this process, how soever imperfect it 

 appears, has been ever sufficient for furnishing decided results. 

 In the two experiments I present, I have obtained for the ave- 

 rage refrigeration : * 



Exper. 21.— (Death 8th hour at about 27°) 4 „ Q , — = 1-90°. 



* As to the autopsy in experiments of this kind : 



1 . I never observed any haemorrhage nor inflammation ; still more, I have sometimes 

 endeavoured in such cases to produce an inflammation by injecting in the pleura or peri- 

 toneum some acrid substances, as cantharids, &c. I could never succeed to produce it, 

 and death always happened before unequivocal signs of inflammation could be observed. 



2. In most instances, the nerve is found divided ; sometimes, however, this is not the 

 case, or the local disorganization produced renders it impossible to determine whether it 

 has been divided or not. It is to be observed, that the disorder in the parts situated 

 near the great sympathetic nerve could not have any influence in the production of the 

 preceding pha?nomcna ; for they are not observable after the extirpation of one of the 

 kidneys : the animal recovers perfectly well. 



3. A very remarkable symptom, I believe, I have observed in every case after the 

 division of the great sympathetic nerve, is the diminution of the heart's strength. Some- 

 times the animal seem* even to die of syncope after some hours. 



