OF VITAL MOTION. 73 



the more marked shakings of paralysis agitans, (both 

 of which involve an unusual disposition to contraction 

 in the muscular system,) are connected with a period 

 in which the nervous power is rapidly on the wane, 

 and often with a state of brain in some degree analogous 

 to the disease last mentioned. 



The causes of convulsive diseases are still very 

 obscure, but in many cases there is reason to believe 

 them associated with signs of debility, and not of 

 strength. This doctrine was very ably advocated by 

 Dr. Todd in the Lumleian lectures, delivered at the 

 College of Physicians during the past and present 

 years, on which occasion it was shown that the 

 muscles were often flaccid and pale, and not firm and 

 of a deep red colour as in health, and the brain much 

 more white and bloodless than natural. This latter 

 condition pallor of the brain was particularly in- 

 sisted upon as a common sign in epilepsy ; and hence, 

 in this disease, which is the worst of the class, we 

 may argue defective innervation, for it is well known 

 that the nervous activity is proportionate to the vas- 

 cularity of the brain. 



The grand and conclusive argument, however, in 

 favour of this view, is to be found in the general 

 spasm of the body which succeeds the departure of 

 life. In this case the phenomenon cannot be owing 

 to increased innervation, for it does not occur until 

 all signs of activity are withdrawn. Nor is this 



