PROTECTIVE INOCULATIONS. 349 



animals which have an acquired immunity against symptomatic an- 

 thrax are also immune against the pathogenic action of the bacillus of 

 malignant oedema; but Kitasato was unable to confirm this. 



Strebel, in 1885, published the results of protective inoculations 

 made in Switzerland in 1884. The inoculations were made in the end 

 of the tail with two "vaccines," with an interval between the two of 

 from nine to fourteen days. The vaccines were prepared by exposure 

 to heat, as above recommended by Arloing, Cornevin, and Thomas. 

 The most favorable season for inoculations was found to be the spring, 

 and the most favorable age of cattle for inoculation from five months 

 to two years. 



In seven Swiss cantons 2,199 cattle were inoculated; 1,810 inocu- 

 lations were made among animals which were exposed in dangerously 

 infected pastures. Of these but 2 died, one two months and the 

 other four months after the protective inoculations. Among 908 in- 

 oculated cattle, which were pastured with 1,650 others not inoculated, 

 the mortality was 0.22 per cent, while the loss among the latter was 

 6.1 per cent. The following year (1885), according to Strebel, the 

 number of inoculations, exclusive of those made in the canton of Bern, 

 w;ts 35,000. The losses among inoculated animals are reported as hav- 

 ing been about five times less than among those not protected in this 

 way. In the canton of Bern, in the same year, according to Hess, 

 15,137 cattle were inoculated by thirt}'-eight veterinarians 12,190 of 

 these were pastured in dangerously infected pastures. The results 

 are said to have been favorable to the method, but the abstract at 

 hand does not give the precise figures. 



In 1887 Kitt reported the results of his investigations, which were 

 confirmatory of those previously published by Arloing, Cornevin, 

 and Thomas, and also of a new method of inoculation, which pre- 

 sented the advantage that a single inoculation was sufficient to confer 

 immunity. This was made in the region of the shoulder with a vac- 

 cine somewhat stronger than that employed by the French bacteriol- 

 ogists, but which was found to be without danger for cattle. It 

 produced only a slight local effect. His vaccine was prepared by 

 heating the moistened flesh of an animal just dead from the disease 

 to 85 to 90 C. for six hours. This did not kill the spores present, 

 but caused a sufficient attenuation in their virulence. 



In a later communication (1888) Kitt recommends that the flesh of 

 the diseased animal be first dried and pulverized, and then subjected 

 to a temperature of 100 C. in streaming steam for six hours, after 

 which it is to be again dried and used for subcutaneous inoculations. 

 The dose is from five to fifteen centigrammes. 



