NATURE OF TOXINES. 157 



diseases he investigated. A similar digestive action has 

 been traced in the case of the tubercle bacillus by Kiihne. 



Further evidence that bacterial toxines are either albu- 

 moses or bodies having a still smaller molecule is furnished 

 by C. J. Martin. This worker, by filling the pores of a 

 Chamberland bougie with gelatine, has obtained what is 

 practically a strongly supported colloid membrane through 

 which dialysis can be made to take place under the great 

 pressure say of compressed oxygen. He finds that in such 

 an apparatus toxines, at least the two kinds tried, will pass 

 through just as an albumose will. 



Brieger and Boer, working with bouillon cultures of 

 diphtheria and tetanus, have, by precipitation with certain 

 metallic salts, especially zinc chloride, separated bodies 

 which show characteristic toxic properties, but which have 

 the reactions neither of peptone, albumose, nor albuminate, 

 and the nature of which is unknown. It has also been 

 found that the bacteria of tubercle, tetanus, diphtheria, and 

 cholera can produce toxines when growing in proteid-free 

 fluids. In the case of diphtheria when the toxine is produced 

 in such a fluid a proteid reaction appears. Of course this 

 need not necessarily be caused by the toxine. Further 

 investigation is here required, for Uschinsky, applying 

 Brieger and Boer's method to a toxine so produced, states 

 that the toxine body is not precipitated by zinc salts, 

 but remains free in the medium. If the toxines are really 

 non-proteid they may, on the one hand, be the final product 

 of a digestive action, or they may be the manifestation of a 

 separate vital activity on the part of the bacteria. On the 

 latter theory the toxicity of the toxalbumins of Brieger and 

 Fraenkel, and of the toxic albumoses of Martin may be due 

 to the precipitation of the true toxines along with these 

 other bodies. From the chemical standpoint this is quite 

 possible. Up to the present no bacterial toxine has been 

 isolated in a pure condition, and therefore we are ignorant 

 of the chemical nature of such bodies. It is possible that 

 present chemical methods are inadequate for the solution of 

 the problem. The toxines we know best are the extracellular. 



