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case from wliicli tho virus has been transmitted. M. Pasteur has fur- 

 ther added to our knowledge of the disease by showing that a virus 

 capable of cultiratiou exists iu the nervous system, especially in the 

 lower part of the brain (medulla oblongata), and in the anterior part of 

 the spinal column. M. Pasteur has farther shown that that portion 

 of the nervous system which contains the virus, the exact nature of 

 which has not yet been demonstrated, will retain it for an indefinite 

 time if kept at a very low temperature, or if left surrounded by car- 

 bonic acid ; but if the nerve matter, which is virulent at first, is ex- 

 l)0sed to the air and by substances which will absorb tho surrounding 

 moisture is kept from putrefaction, it will gradually lose its virulence 

 and become inoffensive in about fifteen days. He has further shown 

 that the action of a weak virus on an animal will prevent the develop- 

 ment of a stronger virus, and from this he has formulated his method 

 of prophylactic treatment. This treatment consists of the successive 

 inoculation of portions of the nerve matter, containing the virus from 

 a rabid animal, which has been exposed to the atmosphere for thirteen 

 days, -ten days, seven days, and four days, until the virulent matter 

 which will produce rabies in any unprotected animal can be inoculated 

 with impunity. A curious result of the experiments of M. Pasteur is 

 that an animal which has first been inoculated with a virus of full 

 strength can be protected by subsequent inoculations of attenuated 

 virus repeated in doses of increasing strength. 



In the horse rabies is invariably the result of the bite of a rabid dog 

 or other rabjd animal. From the moment of inoculation a variable time 

 elapses before the development of any'symptoms. This time may be 

 eight days, or it may be several months ; it is usually about four weeks. 

 The first symptom is an irritation of the original wound. This wound, 

 which may have healed completely, commences to itch until the horse 

 rubs or bites it into a new sore. The horse then becomes irritable and 

 vicious. It is especially susceptible to surrounding media; excessive 

 light, noises, the entrance of an attendant, or any other disturbance 

 will cause the patient to be on the defensive. It apparently sees imag- 

 inary objects; the slightest noise is exaggers-ted into threatening vio- 

 lence ; the approach of an attendant or another animal, especiall^^ a dog, 

 is interpreted as an assault and the horse will strike and bite. The 

 violence on the part of the rabid horse is not for a moment to be con- 

 founded with the fury of the same animal suffering from meningitis or 

 any other trouble of the brain. In rabies there is a volition, a pre- 

 meditated method, in the attacks which the animal will make, which is 

 not found in the other diseases. Between the attacks of fury the animal 

 may become calm for a variable period. The writer attended a case in 

 which, after a violent attack of an hour, the horse was sufficiently calm 

 to bo walked 10 miles and only developed violence again an hour after 

 being placed in the new stable. In the period of fury the horse will 

 bite at the reoijoned original wound; it will rear and attempt to break 



