THE CHEMISTRY OF BACTERIA. 83 



albumose may in turn be split up into pepton. It is evident, 

 then, that a bacterial liquid may contain in solution, albu- 

 min, globulin, albumoses, or even pepton. These protein 

 substances will be precipitated from such culture fluids by 

 the addition of several volumes of absolute alcohol. If 

 harmless, non-poisonous bacteria were cultivated in the 

 liquid the precipitated proteins will produce no effect when 

 injected into an animal. On the other hand, in the case of 

 injurious, disease-producing bacteria the precipitate will be 

 highly poisonous. In this way a tox-albumin was obtained 

 from cultures of the diphtheria bacillus; a tox-albumose 

 from those of the anthrax bacillus, and a toxo-pepton from 

 those of the cholera vibrio. 



The fact that the precipitated protein is poisonous does 

 not prove that the protein itself is actually poisonous. 

 There is every reason to believe that the protein substances 

 present in a bacterial liquid are non-poisonous. When, 

 however, they are thrown out of solution they mechanically 

 drag down the real bacterial poison and, as a result, the 

 precipitate is toxic. If a precipitate of calcium phosphate 

 or of aluminum hydrate is produced in such a liquid it will 

 be likewise poisonous for the reason given. 



Although the " toxalbumins," etc., are not the real 

 bacterial poisons as was at one time supposed, it neverthe- 

 less remains true that certain albuminous substances, 

 elaborated by higher plants and animals, may be intensely 

 poisonous. There is reason to believe that the venom of 

 serpents owes its marked poisonous action to certain pro- 

 teins, such as pepton and globulin. Again, the jequirity 

 seed contains an albumose body, known as abrin, which is 

 very toxic. When injected intravenously, abrin is fatal in a 

 dose of 0.00001 g. per kg. body weight. In other words, 1 g. 

 of abrin is capable of killing 200,000 guinea-pigs, each weigh- 

 ing one pound. The calculated fatal dose for a man weighing 

 130 pounds would be ris grain. A somewhat less poisonous 

 albumose, ricin, has been obtained from the castor bean. 



