488 Rabies. 



inoculation. Tor this purpose, the medulla oblongata, the cerebellum, and the cornu 

 ammonia, that is the whole nucleus of the brain, or the whole brain, are to be 

 preserved in 50% glycerin, or the whole head is separated from the trunk and 

 sent unopened. 



Injections with infectious material by the four first methods named 

 result, as a rule, in producing rabies within 2 to 3 weeks, but some- 

 times the period of incubation is longer. Aujesky observed a period 

 of incubation of 43 days after subdural injection. Gal one of 51 days 

 after intraocular injection, and Klimmer one of 235 days after iiitra^ 

 muscular injection. This relatively long period reduces the practical 

 value of the method, as it does not permit the use of protective vaccina- 

 tion on bitten human beings who depend on the results of the diagnostic 

 inoculation. Besides while the positive result of the inoculation surely 

 indicates the presence of rabies, a negative result does not in the same 

 way preclude its presence; in addition the rabbits may die from septi- 

 cemia when the technique or the material has not been quite clean. 

 Unclean or putrid material, after a previous dilution with physiological 

 solution of sodium chloride (1:250), may be cleansed by filtration 

 through a Berkefeld filter, and with such filtrates a positive resuK may 

 be obtained with tissue kept for 63 days (Mazzei). 



In rabbits inoculated with positive results, the disease is, as. a rule, 

 attended with symptoms of paralysis (see p. 467), and in dogs it takes 

 the usual course. According to Beck, rabbits are also killed within 

 1 to 2 weeks by subdural injections of cerebral substance of dogs which 

 have died from nervous distemper, in which cases, however, the intestines 

 and bladder are also paralyzed, and the disease cannot be transmitted 

 further from one rabbit to another. In paralysis bulbaris infectiosa 

 (see p. 495), the inoculated rabbits violently scratch and rub the place 

 of injection, and as a rule become sick after 2 to 4 days, or at the latest, 

 after 8 days. 



Treatment. Babies which is already developed cannot be 

 arrested or changed in its course. 



More successful is the treatment of wounds from bites for 

 the purpose of preventing the future development of rabies, by 

 destroying the infectious saliva already introduced. One of 

 the most effective methods consists in having the wound bleed 

 profusely, because the flowing blood washes the virus out of 

 the tissues; at the same time it is advisable to wash the wound 

 thoroughly with a disinfectant solution, such as strong vinegar, 

 absolute alcohol, permanganate of potash (1%), carbolic acid 

 (3%), and particularly 1% solution of bichloride of mercury. 

 In cases where the wound comes too late under medical treat- 

 ment, the elimination of the contagion may be attempted by 

 means of a red hot iron or of caustics. The caustics mostly used 

 are muriatic acid, sulphuric acid, nitric acid, iron chloride, 

 lunar caustic, ammonia, etc., in the most concentrated solutions. 

 This treatment is possibly aided by subcutaneous injections 

 in the region of the bite of 1 :10,000 solution of bichloride of 

 mercury, 1:1000 of silver nitrate, 1% solution of carbolic acid, 

 1 :1000 of collargol. In addition the application of a Bier's liga- 

 ture might also prove helpful (Fermi thus saved all test animals, 

 even when the ligature was applied four hours after the infec- 



