77 



3d. In the cases where the temperature was increased, I have 

 constantly found the arteries and capillaries enlarged. 



4th. In some cases, I have found the same changes occurring 

 in the temperature and in the blood-vessels. The temperature 

 at first was greater than usual and the blood-vessels dilated ; 

 afterwards both the temperature and blood-vessels became natu- 

 ral ; and, at last, the temperature becoming lower than usual, 

 the size of the blood-vessels became smaller. 



I need not say that the changes occurring in paralyzed 

 parts in accordance with the size of the blood-vessels were the 

 results of the differences in the amount of blood passing in these 

 parts. 



Now, it will be asked how, in certain cases of palsy, the size 

 of the blood-vessels is larger than usual, and smaller in other 

 cases. I .cannot explain how it is so, but I can assert that it is 

 a fact. 



From the facts and reasonings related in this article, I draw 

 the following conclusions : 



1st. An injury of the nervous system may produce in the 

 parts, which then become paralyzed, either an increase or dimi- 

 nution of temperature. 



2d. The sympathetic nerve and the cerebro-spinal nervous 

 system appear not to be different one from the other, in this 

 respect. 



3d. The degree of temperature of paralyzed parts depends on 

 the quantity of blood they receive ; and this quantity varies ac- 

 cording to the size of the arteries and capillaries of these parts. 



4th. It is a fact, hitherto unexplained, that the arteries and 

 capillaries may be either dilated, normal, or contracted in para- 

 lyzed parts. 



XXIII CAUSE OF THE STOPPING OF THE HEART'S MOVEMENTS, 



PRODUCED BY AN EXCITATION OF THE MEDULLA OBLONGATA OR 

 THE PAR VAGUM. 



E. II. and E. Weber have discovered a singular fact, hitherto 

 unexplained. When the par vagum or the medulla oblongata is 

 excited by a powerful electro-magnetic current, in a living 

 animal, the movements of the heart are suddenly stopped. This 



