170 HUMAN BIOLOGY 



proved by Pasteur to be brought to the surface by 

 earthworms, 

 c. Splenic fever checked by inoculating animals with a 

 virus prepared in a manner somewhat like that of the 

 virus of hydrophobia (see 4 below). 



4. Discoveries relating to hydrophobia (1886). 



a. Hydrophobia demonstrated to be a disease attacking the 



nervous system of victims bitten by mad dogs, wolves, 

 or cats. 



b. Solutions made from fresh spinal cords of animals thus 



bitten, on being injected into healthy animals always 

 cause hydrophobia. 



c. Spinal cords of animals dying of hydrophobia found to 



lose virulence (i.e. disease-producing power) after 

 being dried. 



d. Virus (i.e. glycerine solutions) obtained from spinal 



cords dried fpr var5ang lengths of time found to con- 

 tain corresponding degrees of virulence. 



e. Method of treatment for hydrophobia. 



(a) Cauterization (burning) of wound with strong 



nitric acid. 

 (6) Injection on twenty-one successive days of virus 



of gradually increasing strength. 

 /. Result of Pasteur treatment in Paris; of 21,631 cases 

 treated only 99 victims of the disease died, i.e. less than 

 1 per cent. 



5. Discoveries of other scientists directly due to Pasteur's work, 

 a. Lister's methods of antiseptic treatment of woimds. 



6. Koch's investigations as to the cause and treatment of 

 tuberculosis. 



c. Roux's and von Behring's antitoxin treatment for diph- 

 theria. 



