PRACTICAL RESULTS OF BACTERIOLOGY. 743 



is due. This is an anaerobic bacillus which forms large oval 

 spores. 



The aetiology of the disease was first clearly established by the 

 researches of Arloing, Cornevin, and Thomas (1880 to 1883). 



Strebel, in 1885, published the results of protective inocula- 

 tions made in Switzerland in 1884. The inoculations were made 

 in the end of the tail with two " vaccines," with an interval be- 

 tween the two of from nine to fourteen days. The vaccines were 

 prepared by exposure to heat, as recommended by Arloing, Cor- 

 nevin, 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 in- 

 oculations were made among animals which were exposed in 

 dangerously infected pastures. Of these but two died, one two 

 months and the other four months after the protective inocula- 

 tions. Among 908 inoculated 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, was 35,000. The losses 

 among inoculated animals are reported as having been about five 

 times less than among those not protected in this way. 



In the Bulletin of the Central Society of Veterinary Medicine 

 of France (1892) Guillod and Simon give the results of 3,500 inoc- 

 ulations made since 1884. The mortality among cattle in the re- 

 gion where these inoculations were practiced had been from ten 

 to twenty per cent, but fell to 0*5 per cent among the inoculated 

 animals. 



The success of Pasteur's method of prophylaxis against hydro- 

 phobia is now well established, although the specific germ of this 

 disease has not yet been demonstrated. 



Perdrix (1890), in an analysis of the results obtained at the 

 Pasteur Institute in Paris, calls attention to the fact that the mor- 

 tality among those treated has diminished each year, and ascribes 

 this to improvement in the method. He says : 



" At the outset it was difficult to know what formula to adopt 

 for the treatment of each particular case. Upon consulting the 

 accounts of the bites in persons who have died of hydrophobia, 

 notwithstanding the inoculations, we have arrived at a more pre- 

 cise determination as to the treatment suitable for each case, 

 according to the gravity of the lesions. In the cases with serious 

 wounds we inject larger quantities of the emulsion of cord and 

 repeat the inoculations with the most virulent material. For the 

 bites upon the head, which are especially dangerous, however 

 slight their apparent gravity may be, the treatment is more rapid, 



