RABIES OR HYDROPHOBIA 201 



These so-called "Negri bodies" are demonstrated by special 

 staining methods. When a dog is suspected he is killed and 

 his brain removed. Bits of it are stained for microscopic 

 examination and other pieces are made into an emulsion, 

 which is injected into the brain of a rabbit. If rabies virus 

 be present, this susceptible animal will die within three weeks 

 as a rule. Recently attempts at the cultivation of the rabies 

 virus have been rewarded by the development, under anaero- 

 bic conditions, of minute globoid bodies w r ith a tiny iwo'eus 

 and with such cultures animals have been infected. 



Pasteur found a method for protective inoculation treat- 

 ment against rabies. He found that if the spinal cord of a 

 rabbit suffering from rabies w r ere removed and dried in a 

 vacuum it lost its virulence for other rabbits. If he dried it 

 tw r o weeks nearly all of the virulence was lost, but if only 

 two days, its strength was only slightly impaired. He found 

 that if he inoculated animals with gradually increasing 

 strengths or quantities of emulsions made from these dried 

 rabbits' spinal cords, a certain degree of immunity was 

 obtained. This principle is now used in treating persons 

 bitten by rabid -animals. The treatment is possible after the 

 bite and the outlook is better the sooner after infection the 

 treatment is begun. The spinal cords of rabbits are ground 

 up in glycerin and injections are made under the skin. The 

 patient first receives a dose from a cord dried fourteen days, 

 then from one dried twelve or thirteen days, then ten or 

 eleven. days, and so on until one dried two days is used. The 

 mortality from rabies has been greatly reduced by this 

 method of active immunization. At present there is no very 

 accurate laboratory diagnostic test in rabies. The develop- 

 ment of the symptoms must be awaited to make the diag- 

 nosis in people bitten by rabid animals, but preventive 

 measures take the form of ascertaining that the dog has 

 rabies, using the Pasteur treatment and cauterizing the 

 wound. The ordinary disinfecting dressings of bichloride of 

 mercury and carbolic acid solutions are worthless for the 



