198 PROTEIN POISONS 



stand for ten days in the dark at room temperature. At 

 the expiration of this time the contents of many tubes were 

 placed in a separator and the toluol removed. Having shown 

 by inoculation that the germ contained in these tubes was 

 dead, the exudate thus sterilized was injected into suscep- 

 tible animals subcutaneously, without effect. 



5. Asporogenous cultures were sterilized by exposure 

 for one hundred and ten hours to 16. After exposure 

 to this temperature, the tubes were kept in an incubator 

 at 20, long enough to see that they remained sterile, after 

 which they were injected subcutaneously into susceptible 

 animals, and always without effect. 



6. A number of rabbits and guinea-pigs were simul- 

 taneously infected with anthrax, and after death the livers 

 and spleens were subjected to a hydraulic pressure of 500 

 atmospheres. The fluid thus obtained, which on micro- 

 scopic examination showed the presence of bacteria, was 

 passed through a Chamberland filter, and then injected 

 subcutaneously, intraperitoneally, and intravenously into 

 mice, rats, guinea-pigs, and rabbits, and always without effect. 



7. The experiment of Brieger and Frankel in which they 

 prepared their anthrax toxalbumin was repeated with 

 negative results. 



From these experiments Conradi reaches the following 

 conclusions: "By no method known at present can it be 

 shown that the anthrax bacillus forms either an extra- 

 cellular or an intracellular poison within the bodies of either 

 susceptible or insusceptible animals. Indeed, these experi- 

 ments increase the probability that the anthrax bacillus 

 does not form any poisonous substance, therefore the solu- 

 tion of the manner in which anthrax infection results remains 

 unknown. Whether improved chemical methods will 

 lead to its detection or not cannot be determined, but for 

 the present the anthrax bacillus at least must be regarded 

 as a purely infectious microorganism." If this conclusion 

 reached by Conradi be true, the mechanical interference 

 theory is the best that can at present be offered so far as 

 anthrax is concerned. 



