54 BACTERIAL POISONS OF INFECTIOUS DISEASES. 



mospheres. The resulting fluid was filtered through porcelain and 

 injected into animals without effect. 



7. The experiment of Brieger and Frankel, in which they pre- 

 pared their anthrax toxalbumin, was repeated with a negative result. 



From these experiments Conradi reaches the following conclusion : 

 " By no method known at present can it be shown that the anthrax 

 bacillus forms either an extra-cellular or an intra-cellular poison in 

 the animal body ; indeed, these experiments increase the probability 

 that the anthrax bacillus does not form any poisonous substance. 

 Therefore the solution of the manner in which anthrax infection re- 

 sults remains unknown. Whether improved chemical methods will 

 lead to the detection of a poison or not cannot be predicted, but for 

 the present the anthrax bacillus must be regarded as a purely infec- 

 tions microorganism." If this be true, the mechanical interference 

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

 concerned.^ 



Asiatic Cholera. — ^Bitter has shown that the comma bacillus pro- 

 duces in meat pepton cultures a peptonizing ferment, which remains 

 active after the organism has been destroyed. Like similar chemical 

 ferments, it converts an indefinite amount of coagulated albumin into 

 pepton. It is more active in alkaline than in acid solutions, thus 

 resembling pancreatin more than pepsin. The resemblance to pan- 

 creatin is further shown by increased activity in the presence of cer- 

 tain chemicals, such as sodium carbonate and salicylate. Bitter also 

 demonstrated that this microorganism produces a diastatic ferment, 

 inasmuch as he found that it develops an acid in nutrient solutions 

 containing starch paste ; however, all attempts to isolate this ferment 

 were unsuccessful. A temperature of 60° destroys or markedly de- 

 creases the activity of ptyalin, and this is also true of the diastatic 

 ferment produced by the comma bacillus. 



Fermi isolated the peptonixdng ferment of the cholera germ in the 

 following manner : 65 per cent, alcohol added to gelatin which has 

 been liquefied by the bacillus, precipitates the proteid, but not the 

 ferment ; after twenty-four hours the precipitate is removed by fil- 

 tration, and the ferment precipitated from the filtrate by the addition 

 of absolute alcohol. After being collected on a filter and dried, this 

 ferment may be dissolved in an aqueous solution of thymol and its 

 peptonizing properties demonstrated on gelatin tubes, 



Rietsch believes that the destructive changes observed in the in- 

 testines in cholera are due to the action of the peptonizing ferment. 



Cantani injected sterilized cultures of the comma bacillus into the 

 peritoneal cavities of small dogs and observed after from one-quarter 

 to one-half hour the following symptoms : great weakness, tremor of 

 the muscles, drooping of the head, prostration, convulsive contractions 



' See page 20. 



