614 RABIES AND THE NEGRI BODIES 



slight paralysis of the hind legs, so that the animals can be easily 

 thrown over. They then become restless and cramps of the muscles 

 of the lower jaw occur. The disease now may take on the furious 

 type, but more generally the paralyses become more marked, the 

 hind legs are completely paralyzed, and the front legs become likewise 

 affected. Within a few days great emaciation occurs and death 

 generally follows four to five days after the first symptoms became 

 manifest. After subdural inoculation of the fixed virus the furious 

 type of rabies is never developed in rabbits. 



Preparation of the Attenuated Virus. Where material for the 

 Pasteur treatment of rabies is prepared it is necessary to inoculate 

 at least two rabbits every day, so that a complete series of attenuated 

 viruses is always on hand, even if occasionally one cord should 

 become spoiled by bacterial contamination. The inoculated animals 

 must be kept separate from the others, and they must be carefully 

 watched for the development of any other disease, which would make 

 them unavailable for use for the preparation of rabies virus. The 

 inoculated animals are killed by cutting the throat and bleeding, 

 about twenty-four hours before their expected death from rabies. 

 They are then skinned, the abdominal and thoracic cavities are 

 opened and examined. If no other pathologic lesions but those of 

 rabies are seen the animals are stretched out on a sterile board, 

 abdomen down, and the external surface of the back is thoroughly 

 washed with a solution of lysol. The muscles of the back are removed 

 from the vertebral column and the latter is then opened with special 

 scissors devised for the purpose; next the roots of the spinal nerves on 

 each side are severed with a fine knife, the dura mater is laid open, 

 and the upper part of the cord is tied with a piece of sterile silk 

 or grasped with a small, sterile platinum hook. The cord is then 

 lifted out and cut in the middle of its course. > The upper piece is 

 at once placed in a wide-mouthed sterile flask and so suspended 

 that it does not touch the walls of the vessel. Next a small portion 

 of the lower part is cut off and dropped into a sterile Petri dish or 

 other sterile dish for subsequent examination, as to the absence of 

 contamination by bacteria. Then the small lower portion is removed 

 and treated like the upper portion. The bottles in which the pieces 

 of cord are suspended are of special construction and contain caustic 

 soda which is used to absorb water and bring about the drying out 

 of the material. The flasks with the pieces of cord are kept in a 

 perfectly dark place where the temperature is stationary at 20 C. 

 After the cord has been taken care of the internal organs of the 

 abdominal and thoracic cavities and the brain are carefully dissected 

 to show that they are free from pathologic lesions which would bar 

 the material from use. When the pieces of cord have gone through 

 the drying-out process they are rubbed up and emulsified with sterile 

 bouillon, or, still better, with Babes' fluid, consisting of sulphate of 

 sodium, 5 gr.; chloride of sodium, 6 gr., and water enough to make 



