CH&<PTE<R XIV. 

 {DISEASES 



OF 



THE NERVOUS SYSTEM. 



HY<DROPHO<Bm. 



The antiquity of hydrophobia is not precisely known. Aristotle is the 

 first author to mention this malady, but his account of it is, remarkably 

 incorrect, if the text be not corrupted. He says, " all animals that are bit- 

 ten by a rabid dog are affected with the disease except man ; and that the 

 disease proves fatal to all animals but man." 



Among the ancient authors Caelius Aurelianus treated all the important 

 questions relating to hydrophobia in a most masterly manner. After him 

 centuries passed during which, with but few exceptions, independent 

 observations ceased, and little or nothing was added to the previous 

 knowledge on the subject. 



Investigations were renewed towards the end of the last century by 

 Hunter and other intelligent observers, and recently a more exact knowl- 

 edge of the disease has been acquired through the studies and experiments 

 of Hertwig, Meynell, Youatt, Magendie, Blaine, Virchow, Reder and 

 others. 



Hydrophobia or more properly rabies, which prevails chiefly among 

 animals of the canine species, ( dog, wolf, fox, jackal ) is at the present 

 time accepted as being an acute infectious disease, coming on in the form 

 of a functional disturbance of the central nervous system, without struct- 

 ural changes which can be considered essential to the affection. 



Examinations after death have revealed in most cases diseased appear- 

 ances, but not one has been found to be present invariably, and no local 

 changes have been discovered which could explain all the symptoms. 



Causation.— The, theory of a spontaneous development of rabies so 

 frequently advanced, has been rejected as entirely unfounded by very 



