7 6 4 THE POPULAR SCIENCE MONTHLY. 



At the end of three days three of the sheep folded above the graves 

 had died of splenic fever, while those excluded from them continued 

 to be healthy. This result speaks for itself. 



Malignant pustule, which is simply splenic fever, affects shepherds, 

 butchers, and tanners, who handle the flesh and hide of tainted animals. 

 Inoculation with the bacillus almost always occurs in consequence of 

 a wound or scratch on the hands or face. In Germany, fatal cases of 

 anthrax have been observed, in which the disease has been introduced 

 through the mouth or lungs, as in the case of the sheep observed by 

 Pasteur. The human subject appears, however, to be less apt to con- 

 tract the disease than herbivora, since the flesh of animals affected by 

 splenic fever, and only killed when the microbe is fully developed in 

 the blood, is often eaten in farm-houses. In this case the custom prev- 

 alent among French peasants of eating overcooked meat constitutes 

 the chief safeguard, since the bacteria and their germs are thus de- 

 stroyed. 



The rapidity with which anthrax is propagated by inoculation gen- 

 erally renders all kinds of treatment useless : if, however, the wound 

 through which the microbe is introduced can be discovered, it should 

 be cauterized at once. This method is often successful in man. The 

 pustule is cauterized with red-hot iron, or with bichloride of mercury 

 and thymic acid, two powerful antiseptics, certain to destroy the bac- 

 teridium. It is expedient, as a hygienic measure, to burn the tainted 

 carcasses, and, if this is not done, they should be buried at a much 

 greater depth than is usually the case. 



But the preservative means on which chief reliance is now placed 

 is vaccination with the virus of anthrax. Pasteur has ascertained that 

 when animals are inoculated with a liquid containing bacteridia of 

 which the virulence has been attenuated by culture carried as far as 

 the tenth generation, or even further, their lives are preserved. They 

 take the disease, but generally in a very mild form, and it is an im- 

 portant result of this treatment that they are henceforward safe from 

 a fresh attack of the disease ; in a word, they are vaccinated against 

 anthrax. 



In the cultures prepared with the view of attenuating the microbe, 

 it is the action of the oxygen of the air which renders the bacteridium 

 less virulent. It should be subjected to a temperature of from 42 to 

 43 in the case of Bacillus anthracis, to enable it to multiply, and at 

 the same time to check the production of spores which might make 

 the liquid too powerful. At the end of the week, the culture, which 

 at first killed the whole of ten sheep, killed only four or five out of 

 ten. In ten or twelve days it ceased to kill any ; the disease was per- 

 fectly mild, as in the case of the human vaccinia. After the bacteridia 

 have been attenuated, they can be cultivated in the lower tempera- 

 ture of from 30 to 35, and only produce spores of the same attenu- 

 ated strength as the filaments which form them (Chamberland). 



