792 BACTERIOLOGY. 
mallein is another. According to Buchner and Rémer, 
all bacterial proteins are very similar in their action, 
and Mathes maintains that deutero-albumose, which is 
obtained by the action of pepsin on albumin and has 
no connection with bacteria, has an effect on tubercular 
guinea-pigs somewhat similar to tuberculin. 
Toxins—Active Proteids. ToxaLBumins. Fraenkel 
and Brieger, confirming the statements of previous in- 
vestigators (Christmas, Roux and Yersin, and Hankin), 
have shown that amorphous poisons having an intense 
and often specific toxic action—that is an effect similar 
to that produced by infection with the living organism 
—may be precipitated from bouillon cultures by agents 
precipitating albumin. They therefore called these 
poisons ‘‘toxalbumins,’’ and regarded them as being 
analogous to the toxalbumins of vegetable origin, like 
ricin from the castor-oil bean (Ricinis communis), 
and abrin from the jequirity bean (Abras precatorius). 
The majority of investigators, however, consider these 
poisons to be “ labile”’ albuminous substances, which 
are derived from the bacterial cells. Some have assumed 
that they were similar to snake poisons or to the 
enzymes. Like these substances, they are very sensi- 
tive to the action of heat, chemical agents, light, ete. 
Toxalbumins are obtained as crude substances by the 
precipitation of the products of fully developed cultures 
in bouillon under a vacuum, with absolute alcohol or 
ammonium sulphate, after the culture fluid has been 
freed from living germs by its passage through a por- 
celain filter. When ammonium sulphate is used the 
precipitate is freed from this reagent by dialysis 
‘1 So-called ‘‘labile’’ substances are such as are prone to undergo chemical 
changes or alterations of atomic structure; unstable. 
