206 RABIES CANINA. 



But if none of these causes engender the rabid malady, to what 

 can we attribute the extreme variations in its prevalence at one time 

 in preference to another ; its visitation of one district, and its al- 

 most total absence from those around it ? Can we account for 

 these on the simple principle of contagion ? that is, must every 

 dog be actually inoculated with the rabid virus ? To this I now 

 feel a difficulty in replying, cases having occurred wherein any 

 rabid inoculation was to appearance doubtful. But, on the other 

 hand, no clear case that this disease has arisen without the appli- 

 cation of rabid virus has ever been distinctly proved, though often 

 asserted. Certain changes may take place in the canine constitu- 

 tion which may prove decidedly favourable to the germination of 

 - the rabid virus^^, and to which we ascribe its appearing endemial 

 at one time and epidemial at another. The same circumstances, 

 also, may occasion a more early development of the disease (as I 

 have already proved with regard to heat and excitement), and in 

 this way increase its apparent prevalence, by bringing numerous 

 cases together i which would otherwise be spread over a greater ex- 

 tent of time. 



Was the dog the immediate species of the canince in which 

 rabies first originated? — This is a question not easy of solution, 

 though many, from localizing their views, would be led to promptly 

 answer yes : but where the wolf is still found in great numbers, 

 he has equal aptitude to take on the disease by inoculation ; even 

 more disposition to spread it ; and at least equal capability, from 

 the virulence of his virus, to make it certain in effect : some ac- 

 counts would even give to it a most frightful activity^^. A p7'iori^ 



" It was the decreased predisposition to take on the disease at that parti-, 

 cular time which made the experiment of Dr. Hertwig, veterinary professor at 

 Berlin, so unproductive. He inoculated fifty-nine dogs with the virus, and 

 yet only fourteen became rabid : at another time it is not unlikely that the 

 numbers might have been very different. 



'2 Fortunately, the ravages of the rabid wolf are unknown among us ; but 

 in France, Spain, and Germany, they are but too common. His savage na- 

 ture makes him, under the excitement of this inflammatory disease, highly 

 ferocious, and he seeks objects of every kind wherein to propagate his own 



