On Rabies. 



59 



then partially recovered. It however ultimately relapsed and died on 

 the 23rd day. 



On post-mortem examination the appearances were found to be very 

 distinctly marked and diagnostic, the brain and spinal cord con- 

 gested and softened, the stomach showing moderately large and 

 distinct hemorrhagic spots (ecchymoses) ; the condition of the other 

 organs, too, was typical. 



In this case, as in the dog, the incubation period was remarkably 

 short. The temporary recovery is unparalleled in my observations, but 

 is recorded by M. Pasteur as sometimes occurring. Other inocula- 

 tions were made in the same manner intracranially with virus from 

 different sources, all with similar results as to infection and the 

 symptoms produced, varying only in the length of the incubation 

 period. 



These cases in dogs and rabbits proved sufficiently that by cerebral 

 inoculation of a healthy animal with portions of the medulla of 

 a rabid street dog, or an animal infected from it, paralytic rabies is 

 produced, which in the dog does not differ in its essential characters 

 from ordinary street rabies ; in the rabbit, however, its occurrence 

 was not so well recognised previous to M. Pasteur's experiments, and 

 the symptoms are different from those in the dog. 



In order, therefore, to meet the objection that these symptoms are 

 not those of infective rabies or lyssa, subcutaneous inoculations with 

 infective medulla were practised. 



With this object a young healthy dog was injected under the skin 

 of the back with half a c.c. of the mashed cord of a rabbit that had 

 just died with the usual symptoms of paralytic rabies. 



The dog, beyond at times an apparently increased irritability and 

 disposition to bite, which may have been merely the result of confine- 

 ment, showed no appreciable change until the thirty-ninth day after 

 inoculation, when it was observed to be markedly snappish and 

 irritable ; on the following day it was very dull and indisposed to 

 move or notice anything ; this increased, and it became paralysed in 

 the hind limbs, lying on its side ; there appeared constant irritation 

 of the skin, at which it was perpetually scratching, with continued 

 twitching of the muscles of the neck and trunk ; it frequently uttered 

 a short yelp, altered in tone and characteristically metallic, but not 

 the typical prolonged howl of rabies. 



It died during the night of the forty-second day, with post-mortem 

 appearances that were sufficiently characteristic ; it was clearly a case 

 of rabies with tetanic symptoms more pronounced than usual, but in 

 its essential characters did not differ from street rabies in the same 

 animal. 



In similar manner rabbits were inoculated subcutaneously ; many 

 experiments failed to produce infection, as did also one in another 



