RABIES. 15: 



disease, which is of rather frequent occurrence, and quite 

 recently has been remarkably prevalent in England and 

 some of the United States of America, It occurs oftener 

 amongst dogs than other animals. It is very rarely noticed 

 in Australia and New Zealand, and has, until recently, been 

 comparatively rare in Canada and the United States. It is, 

 however, very common in Peru, Chili, and some other 

 countries. Rabies belongs to the class of zymotic diseases, and 

 is communicable by inoculation to all warm-blooded animals. 

 It is stated by some writers to be spontaneously generated, 

 but I believe it to be due in every case to contagion. 

 Climate does not appear to exert any amount of influence 

 over its production. It is very generally imagined by 

 people that dogs are more liable to have the disease dur- 

 ing very hot weather ; hence it is that laws have been 

 passed nearly everywhere requiring dogs to be muzzled 

 during the hot season. It is barely possible that the 

 disease may be invited or developed by the irritation 

 caused by the muzzle, and want of a proper supply of 

 water. However, experience proves that hot weather does 

 not exercise the slightest influence, so far as being the 

 actual cause or producing the disease is concerned. The 

 contagious principle or virus exists only in the fixed form, 

 and never in the volatile form, so far as is known. The 

 virus exists in every tissue of the body, but in the brain, 

 spinal cord, and saliva it is found in its most potent forms. 

 The potency of the virus is, however, soon lost after death 

 occurs. It is claimed that the virus becomes weaker after 

 passing through several bodies. The first bites of a rabid 

 dog are said to be the most dangerous. Tiie period of 

 incubation varies from ten days to six or seven months, 

 and in man cases have been observed wherein the period of 

 incubation varied from five days to ten months, and a few 

 cases are recorded wherein several years elapsed after the 



