ANTHRAX. 291 



I : 1000 solutions of mercuric chlorid the spores are not 

 destroyed earlier than after the lapse of twenty hours (Gep- 

 pert). In sterilized distilled water or tap-water anthrax- 

 bacilli survive only for three days, but the spores for from 

 one hundred and fifty-four days to a year. The lower, fur- 

 ther, the temperature, the better do the anthrax-organisms 

 withstand the injurious influence of the water. Anthrax- 

 bacilli in distilled and other water have been demonstrated 

 to undergo sporulation at a temperature of 20 C. (68 F.). 

 The bacilli are rapidly destroyed by the influence of putre- 

 faction, while the spores have been found alive in putrefac- 

 tive mixtures after a month. 



The statements made apply only to robust spores, the 

 descendants of highly virulent bacilli. Anthrax-spores 

 of indifferent source do not invariably react alike ; thus, 

 von Esmarch was able to render some anthrax-bacilli in- 

 nocuous by means of 5 per cent, carbolic acid within two 

 days, and by means of live steam at a temperature of 100 

 C. (212 F.) within three minutes. 



The Occurrence of Anthrax in Animals. The animal 

 most susceptible to anthrax is the sheep, and it is often 

 attacked by the disease spontaneously. There is, however, 

 one variety of sheep that is immune namely, the Algerian 

 sheep. This immunity is not dependent upon climatic con- 

 ditions, for European sheep transported to Algiers were as 

 readily attacked by anthrax as at home. White mice and 

 guinea-pigs succumb likewise with regularity to experi- 

 mental anthrax-infection ; rabbits are somewhat more resist- 

 ant ; but none of these three species of animals is scarcely 

 ever exposed to natural infection. Cows and calves not 

 rarely succumb to spontaneous anthrax, although they 

 prove rather refractory to experimental subcutaneous infec- 

 tion. Horses, antelope, deer, goats, at times acquire an- 

 thrax ; swine more rarely. With regard to the much- 

 discussed immunity of white rats to anthrax, it appears 

 that young animals die of anthrax after experimental 

 infection, whereas old animals usually exhibit only a 

 local lesion, from which they recover. Carnivorous ani- 

 mals (dogs, cats, etc.) rarely are attacked spontaneously 

 by anthrax. Experimentally, the disease can be induced 

 in mature animals only by intravenous injection of the 

 bacilli. New-born or quite young dogs, on the other hand, 

 prove extremely susceptible. Birds, reptiles, batrachians, 



