510 APPENDIX B. 



after symptoms of the disease are strongly developed. The work of these 

 observers has been confirmed in America by Ravenel and McCarthy, 

 but Spiller has noted similar changes in man in a case of Landry's 

 paralysis and does not think the lesion specific of rabies. Nevertheless, 

 given a case of " street-rabies," the diagnosis can be made with cer- 

 tainty much earlier than by the inoculation method. The changes in 

 the other parts of the body are unimportant. 



Experimental pathology confirms the view that the nervous system 

 is the centre of the disease by finding in it a special concentration of 

 what, from want of a more exact term, we must call the hydrophobic 

 virus. Earlier inoculation experiments made by subcutaneous injection 

 of material from various parts of animals dead of rabies had not given 

 uniform results, as, whatever was the source of the material, the disease 

 was not invariably produced. Pasteur's first contribution to the subject 

 was to show that the most certain method of infection was by inserting 

 the infective matter beneath the dura mater. He found that in the case 

 of any animal or man dead of the disease, injection by this method of 

 emulsions of any part of the central nervous system, of the cerebro-spinal 

 fluid, or of the saliva, invariably give rise to rabies, and also that the 

 natural period of incubation was shortened. Further, the identity of 

 the furious and paralytic forms was proved, as sometimes the one, some- 

 times the other, was produced, whatever form had been present in the 

 original case. Inoculation into the anterior chamber of the eye is nearly 

 as efficacious as subdural infection. Infection with the blood of rabic 

 animals does not reproduce the disease. There is evidence, however,, 

 that the poison also exists in such glands as the pancreas and mamma. 

 Subcutaneous infection with part of the nervous system of an animal 

 dead of rabies usually gives rise to the disease. 



In consequence of the introduction of such reliable inoculation 

 methods, further information has been acquired regarding the spread 

 and distribution of the virus in the body. Gaining entrance by the in- 

 fected wound, it early manifests its affinity for the nervous tissues. It 

 reaches the central nervous system chiefly by spreading up the peripheral 

 nerves. This can be shown by inoculating an animal subcutaneously 

 in one of its limbs, with virulent material. If now the animal be killed 

 before symptoms have manifested themselves, rabies can be produced 

 by subdural inoculation from the nerves of the limb which was infected. 

 Further, rabies can often be produced from such a case by subdural in- 

 fection with the part of the spinal cord into which these nerves pass, 

 while the other parts of the animal's nervous system do not give rise to 

 the disease. This explains how the initial symptoms of the disease 

 (pains along nerves, paralysis, etc.) so often appear in the infected part 

 of the body, and it probably also explains the fact that bites in such richly 



