162 RABIES. 



the nature of the disease and development, we shall more certainly lead 

 to the remedy. 



It is proved that the virus of rahies always develops in the nervous sys- 

 tem, brain, spinal cord, nerves, etc., and never invades at once all these 

 parts. It may conceal itself in the spinal cord and then attack the brain 

 or vice versa. We find that the uppermost part of the spinal cord, which 

 is called the bulb, is invariably the seat of the poison, so that when an 

 animal dies of rabies we are able to obtain from this bulb, some of the 

 virus of rabies which will produce the disease, if inoculated on the surface 

 of the brain. You can test this on any dog of any kind by trephining. 

 The experiment never fails and has been performed by us numerous times 

 on hundreds of animals. 



The invariable existence of the virus in the bulb of dead animals from 

 this disease, the certainty of communicating rabies to other animals by 

 opening the brain are truths now established. As to the origin of hydro- 

 phobia or rabies, all forms came originally from the bite of a mad dog. 

 Rabies never rises spontaneously in the dog or other animals; all cases to 

 the contrary are non-authentic. 



There must have been a first case of rabies, but this touches problems 

 unsolvable. It touches the problem of life. Who would maintain that an 

 ovum always came from an ovum and that the first ovum spontaneously 

 developed? Science does not argue about the origin of things. No one is 

 benefited and such questions are beyond its province. 



Nothing is more variable than the natural period of incubation in this 

 disease. One dog goes mad in four or six weeks, another in two or three 

 months. By one method of inter-cranial inoculation, the period of incuba- 

 tion is shortened and known approximately. The duration of incubation 

 may also depend upon the quantity of active virus reaching the nervous 

 system unchanged. The quantity of virus may be infinitesimal. 



On May 10th., 1882, ten drops of a fluid, obtained by macerating, in a ster- 

 ilized broth, a portion of the bulb of a wandering mad-dog, were intro- 

 duced into the popliteal vein of a dog. A second dog was inoculated with 

 one one-hundredth, and another dog one two-hundredth of the quantity. 

 The first dog had rabies on the eighteenth day, the second on the thirty- 

 fifth, and the third was unaffected, the quantity of virus not being sufficient. 

 This dog was again tested and contracted rabies twenty-two days later. 

 If we operate by trephining we obtain a method certain in its effect. If we 

 take mad dogs at any season, and in each case isolate the bulb and inocu- 

 late with the material by trephining a few rabbits, the phenomena will be 

 regular. No matter what dog be used the incubation will fall within 

 twelve or fifteen days; it will never be eleven, ten, or eight days though it 

 may be over fifteen days. Other instances of the peculiarities of the virus 



