Serum Therapy 533 



tenuated by cultivation at 42 C. for a sufficient length of 

 time, the bacilli forming no spores and gradually losing 

 their virulence at this temperature. The first vaccine was kept 

 from fifteen to twenty days at 42 C. It killed mice and 

 guinea-pigs one day old, but was without action on guinea- 

 pigs of adult size. The second vaccine only remained at 

 the temperature of 42 C. for from ten to twelve days 

 and killed mice, guinea-pigs, and occasionally rabbits. 



The second vaccine is administered from two to three 

 weeks after the first is given, by hypodermic injection into 

 the tissues of the neck or flank. Of each broth culture 

 about i c.c. is administered. The animals frequently be- 

 come ill. 



Pasteur demonstrated the value of his method in 1881 at 

 Pouilly-le-Fort, in a manner so convincing to the entire 

 world that it was immediately put into practice in France. 

 Roger* says that between 1882 and 1894 there were 

 1,788,677 sheep vaccinated, with a mortality of 0.94 per 

 cent., the previous death-rate having been 10 per cent. 

 There were also 200,962 cattle vaccinated, with a reduction 

 of the death-rate from 5 per cent, to 0.34 per cent. 



Chamberland has shown that protective inoculation by 

 Pasteur's method has diminished the death-rate from 10 

 per cent, for sheep and 5 per cent, for cattle to about 0.94 

 per cent, for sheep and 0.34 per cent, for cattle, so that 

 the utility of the method is scarcely questionable. The 

 method has been less successful elsewhere than in France, 

 and has sometimes caused the death of the animals to be 

 protected. 



Protection against anthrax can be afforded in other ways. 

 Hiippe found that the simultaneous inoculation of bacteria 

 not at all related to anthrax will sometimes cause the 

 animal to recover. Hankin found in the cultures chemic 

 substances, especially an albuminose, that exerted a pro- 

 tective influence. Rettgerf prepared "prodigiosus powder" 

 from potato cultures of B. prodigiosus, which when injected 

 into guinea-pigs during experimental anthrax infection pro- 

 longed life or induced recovery. 



Serum Therapy. In 1890 Ogata and Jasuhara showed 

 that experiment animals convalescent from anthrax pos- 

 sessed an antitoxic substance in the blood of such strength 



*"Les Maladies Infectieuse," n, p. 1489. 



t "Jour, of Infectious Diseases," vol. n, No. 4, p. 562, Nov. 25, 1905. 



