Protective vaccinations 471 



The loss due to these accidents is estimated at oue-half per cent 

 in sheep and a quarter per cent, in the Bovidae. 



The refractory condition resulting from the vaccination requires 

 for its development a period of about a fortnight. The immunity is 

 then very substantial and lasts for a fairly long time. Recording to 

 Chamberland 60 7o of the sheep retain their immunity a year after 

 they have been vaccinated. But as a great number of animals 

 then become susceptible, it is usual to revaccinate annually. 



According to the statistics furnished by the vaccine department 

 of the Pasteur Institute there have been vaccinated, up to the Ist 

 of January 1900, a total of 4,9/1,494 sheep, and 708,980 cattle. 

 Abroad the corresponding figures are 3,831,948 and 1,869,445. Alto- 

 gether, the number of animals vaccinated amounted to 11,381,867, 

 of which 3,626,206 have been treated with the vaccine furnished by 

 the Budapest Laboratory. 



The results of the anti-anthrax vaccinations were found to be so 

 favourable that it was unnecessary to introduce any improvements 

 in technique. Attempts have certainly been made to prepare anti- 

 anthrax serums, and these have been successful, but up to the present 

 such serums have not been introduced into practice. 



VI. Vaccinations against symptomatic anthrax. Symptomatic 

 anthrax, which is often confounded with true anthrax, is set up, as 

 demonstrated by Arloing, Cornevin, and Thomas, by a specific anae- 

 robic micro-organism to which has been given the name of Bacillus 

 chauvaeL Immediately after the discovery of the attenuation of [494] 

 viruses and of vaccines against fowl cholera, the three observers 

 above mentioned tried to apply it to symptomatic anthrax. Finally 

 they devised a method which was soon adopted in practice, and 

 which, for nearly twenty years, has been used in the vaccination of 

 the Bovidae in countries where symptomatic anthrax is most preva- 

 lent. This is especially the case in mountainous districts, such as 

 Switzerland, the Bavarian Alps, the Dauphine, L'Auvergne, etc. 



Arloing, Cornevin, and Thomas^ prepare two vaccines against 

 symptomatic anthrax by a method very different from that used in 

 the preparation of the Pasteurian anti-anthrax vaccines. They take 

 the virus from the muscles invaded by the micro-organism ; they 

 triturate a piece of the tumefied muscle in a mortar, adding to it a few 



1 "Le charbon bacterien," Paris, 1883 ; 2e edition, 1887. 



