62 



Mr. G. F. Dowdeswell. 



With it I inoculated three rabbits intracranially by trephining; all 

 three showed a rise of temperature towards the end of the sixth day, 

 and died with typical symptoms and appearances of infection shortly 

 afterwards. 



As I had diluted the nerve substance about twice as much as I 

 usually did medulla, and only injected the same quantities, producing 

 infection without any variation in the incubation period, it is shown 

 to be fully as virulent as the cerebro-spinal substance ; and we may 

 conclude that the tissues both of the central and peripheral nervous 

 systems are equally the seat of the virus.* 



At an early stage of the investigation I made a series of experiments 

 upon the relative activity of the virus of the spinal cord and medulla 

 oblongata of the same animals, and T found that as shown by the 

 duration of the incubation period, there was no appreciable difference 

 whatever in the infective virulence of the two. 



I have tried the infectivity of the tissues of the salivary glands of a 

 rabid dog, or the secretion expressed from them, taking portions of 

 the parotid and submaxillary, crushing each in a mortar, adding a 

 small portion of bouillon, with which it was macerated for a time, the 

 fluid then being injected intracranially in rabbits. 



Of two rabbits inoculated from the submaxillary gland one died 

 on the 2nd day apparently from an accidental cause, the other was 

 found dead in the morning of the 4th day, no symptoms of 

 infection having been apparent nor any pathognomonic appearances 

 on post-mortem examination. Two other animals were inoculated 

 intracranially from its medulla and both remained unaffected. The 

 two rabbits inoculated from the parotid both developed symptoms of 

 infection on the 17th day, and died during the 20th with typical 

 appearances, showing apparently that the tissues or secretion of the 

 parotid gland are infective, but much less actively so than the 

 medulla. 



* Uertwig (op. ext., infra, vide p. 65) failed to produce infection in six dogs 

 inoculated with the crural and sympathetic nerves of other rabid animals. 



Eossi, of Turin (' Torino, Accad. Sei. Mem.,' 1805-1808, p. 94) asserts that he 

 produced rabies in a dog after an incubation period of eighteen days by inoculating 

 it ii? the tail with a portion of the crural nerve of a rabid cat just killed. This cat, 

 however, was one of "several" which he states that he rendered rabid by con- 

 fining in a room without food or drink ; then killing them, he inoculated the 

 different fluids of the body to ascertain which besides the saliva most readily 

 induced rabies, and found that only that secretion and the nerves ivhile warm, did 

 so. In a subsequent communication (' Memorie,' &c, vol. 30, 1826, p. 22) he further 

 states that two dogs became rabid by being bitten by a cat confined as described, 

 but that by similar means he was unable to excite rabies in dogs. 



His experiments appear to have been numerous, but his statements on this point 

 are difficult to underst and if his own conclusion be rejected, that rabies in the cat is 

 spontaneous and may be produced experimentally. 



