VITAL PHENOMENA OF BACTERIA. 73 
through parchment against running water, and after 
concentration the substances are again precipitated by 
absolute alcohol. Recently it has been found that zine 
chloride separates these bodies quantitatively, and that 
the toxins may be obtained from this precipitate by 
means of sodium phosphaté (Brieger and Boer). 
All along, however, some doubt has been expressed 
as to whether these so-called toxalbumins were really 
only obtainable by precipitation from albumin or 
whether they had anything to do with albumin at 
all. With regard to tetanus poison, Brieger and 
Cohn have now succeeded in obtaining what they 
consider an almost pure toxin from the crude poison by 
means of acetate of lead and ammonia. This substance 
gives a slight violet color with copper sulphate and 
soda solution, but otherwise no albumin reaction; it 
contains neither phosphorus nor sulphur, and is appar- 
ently not an albuminous substance. The statement 
previously made by Uschinsky that he had obtained 
albuminoid tetanus and diphtheria poisons in culture 
media devoid of albumin could not, heretofore, be con- 
firmed, owing to the difficulty experienced by most 
investigators in getting a sufficient growth of these 
organisms on such media. Brieger and Cohn have 
‘found that cholera spirilla produce a non-albuminous 
poison in Uschinsky’s culture media (free from albu- 
min); and now diphtheria toxin has been recognized to - 
be non-albuminous (Brieger and Boer). It is becoming 
more and more customary to call proteid bacterial poisons 
simply tozins, irrespective of their composition, and to 
ignore the existence of the above-described crystallizable 
toxins of simple constitution. 
With regard to the other properties of these toxins, 
