PROPHYLACTIC TREATMENT OF HYDROPHOBIA 579 



There is no doubt that between rabies and the bacterial 

 disease's \\v have studied there are at every point analogies, the 

 most striking U'ing the protective inoculation methods, the <li- 

 co\ cry of which constitutes the great work of Pasteur ; and every- 

 thing points to a micro-organism being the cause. The organism, 

 whatever it is, is, in its infective form, probably very small, as it 

 can pass through the coarser Berkefeld filters, and also occasion- 

 ally through the coarser Chamberland candles. Evidence that it 

 is the organism itself which passes through, is found in the fact 

 that when iin animal dies from infection with the filtrate, a 

 small portion of its central nervous system will originate the 

 disease in a fresh animal. Judging from our knowledge of 

 similar diseases, we would strongly suspect that it is actually 

 present in a living condition in the central nervous system, the 

 >ali\a. etc., which yield what we have called the hydrophobic 

 virus, for by no mere toxin could the disease be transmitted 

 through a series of animals, as we shall presently see can be 

 done. A toxin may, however, be concerned in the production 

 of the pathogenic effects. Reinlinger found that death with 

 paralytic symptoms followed the injection of filtered virus, but 

 that the nervous system of the dead animals sometimes did not 

 reproduce rabies. He explains this occurrence by supposing that 

 the filtrate contained a toxin but not the actual infective agent. 

 The resistance of the virus to external agents varies. Thus a 

 iMTvous system containing it is virulent till destroyed by putre- 

 faction ; it can resist the prolonged application of a temperature 

 of from - 10 to 20 C., but, on the other hand, it is rendered 

 non-virulent by one hour's exposure at 50 C. Again, its 

 potency probably varies in nature according to the source. 

 Thus, while the death-rate among persons bitten by mad dogs is 

 about 16 per cent., the corresponding death-rate after the bites 

 ot wolves is 80 per cent. Here, however, it must be kept in 

 view that, as the wolf is naturally the more savage animal, the 

 number and extent of the bites, i.e. the number of channels of 

 entrance of the virus into the body and the total dose, are 

 u r reater than in the case of persons bitten by dogs. As we shall 

 see, alterations in the potency of the virus can certainly be 

 effected by artificial means. 



The Prophylactic Treatment of Hydrophobia. Until the 

 publication of Pasteur's researches in 1885, the only means 

 adopted to prevent the development of hydrophobia in a person 

 bitten by a rabid animal had consisted in the cauterisation of 

 the wound. Such a procedure was undoubtedly not without 

 effect. It has been shown that cauterisation within five minutes 



