12 TOXINES AND ANTITOXINES. 



of impurities, either of inorganic nature (ash) or of organic nature 

 (albuminous substances). A pure toxine is, up to the present, as 

 little known as a pure enzyme, and it is scarcely to be expected 

 that it will be successfully prepared in the immediate future. 

 Even in the case of preparations, which were still not pure 

 although containing relatively very few impurities, BRIEGEE and 

 BOER obtained such minute quantities that further purification 

 was out of the question. Moreover, attempts to prepare toxines 

 on proteid-free culture media (UscniNSKY, loc. cit.) have given 

 very unpromising results. 



As regards the chemical nature of toxines there is, therefore, 

 practically nothing known. Just as in the case of enzymes, to 

 which they stand in such close relationship, they were at first 

 regarded as albuminous substances and termed toxalbumins. The 

 more thoroughly, however, the preparations were purified, the 

 stronger became the idea that the albuminous substances, 

 although very difficult of removal, were only impurities, and 

 that the pure toxines themselves were in all probability not 

 proteids in the ordinary sense. And BRIEGER himself, to whom 

 we owe the conception of toxalbumins, succeeded in preparing 

 toxine preparations which no longer gave the ordinary reactions 

 of proteids (cf. Tetanus Poison) any more than did toxines 

 produced in albumin-free culture media. 



In the case of other toxines, too, successful attempts have 

 been made to reduce, very considerably at least, the albuminous 

 impurities. 



JACOBY 1 succeeded by means of digestion with trypsin in 

 obtaining preparations of ricine that were practically free from 

 albuminous substances. The active principle itself is not at- 

 tacked by this enzyme, whereas the albuminous substances 

 present are decomposed by it. Since then these decomposition 

 products, like trypsin itself, cannot be precipitated by ammonium 

 sulphate, even in a 50 per cent, solution, whereas ricine is readily , 

 precipitated at that degree of concentration, it is possible by this 

 means to obtain from the mixed products of the digestion pre- 

 parations of ricine that no longer give the proteid reactions. 



That is the only negative knowledge that we have of the 

 constitution of toxines. With this exception we have to content 

 ourselves with stating that they are bodies of high molecular 

 weight, probably allied to the proteids with which they corre- 

 spond in certain properties, and still more closely related to the 

 ferments, whose constitution is equally a matter of hypothesis, 



1 Jacoby, "Die chemische Natur des Ricins," Arch. exp. Path., xlvi., 

 98, 1901 ; Hofm. JSeitr., i., 51, 1901. 



