HI I'lITIl K IUA. 125 



instances weeks utter tin- inoculation, and WAS pre- 



<-edcd by marked emaciation. 



The cultures first employed were seven days old ; older 

 cultures (six weeks) contain more of the poison, and the 

 symptoms appear within a lew hours. In cultures espe- 

 cially rich in the poison, a small amount (from 0.2 to '1 c.c. ) 

 injected under the skin in guinea-pins sulliees to induce the 

 symj)toms. .Mice and rats are markedly insusceptible, but 

 succumb to large doses. 



Heating to 100 for twenty minutes renders the poison 

 inert, and a temperature of 58 maintained for two hours 

 markedly lessens its virulence. 



The poisonous substance is precipitated by al>solute 

 alcohol, and is carried down mechanically on the addi- 

 tion of calcium chloride to the filtered cultures. These 

 investigators agnv with LOFFLER that the poison belongs 

 to the en/ymes. The great toxicity of this substance is 

 indicatnl by the statement of Itoux and YERSIN that 0.4 

 milligramme suffices to kill eight guinea-pigs or two rab- 

 bits, and that 2 centigrammes of the calcium chloride 

 precipitate, containing aboutO.2 milligramme of the pure 

 poison, will kill a guinea-pig within four days. 



BRIEGER and FRANKEL have made a very complete 

 study of the chemical products of the LOFFLER bacillus. 

 They employed cultures of bouijlon and peptone containing 

 from five to six per cent, of glycerin, and others containing 

 ten per cent, of sterile, fluid blood-serum. The latter were 

 found to IM- most suitable. In these the bacilli grow most 

 abundantly. In all cases they confirmed the statement of 

 Itoux and YERSIN that the cultures, at first alkaline, be- 

 come strongly acid, and finally again alkaline, with the 

 exception that the glycerin cultures remained acid. 



For the removal of the bacteria two methods were em- 

 ployed. First the bacilli were destroyed by heat \Vhen 

 a temperature of 100 was employed the cultures were 

 rendered inert, but it was found that exposure for from 

 three to four hours to a temperature of 50 was sufficient 

 t<> destroy the germs, while the virulence of the chemical 

 products was not affected. The second method of removing 



