TOXINS. 35 



microorganisms, including those of cholera, diphtheria, tetanus and 

 typhoid fever, in the following menstruum : 



From these cultures he obtained toxins which were not less virulent 

 than those formed in ordinary beef-tea, and thus demonstrated that 

 their production is due to synthetical processes. 



Ehrlich,* as the result of a long series of experiments made upon 

 animals with toxins and antitoxins, has formulated the following 

 conclusions concerning the constitution of the diphtheria toxin : 



1. The diphtheria bacillus produces two kinds of substances : (a) 

 toxins, (6) toxons, both of which combine with anti-bodies. In fresh 

 bouillon cultures toxins and toxons exist in the same proportions. 



2. The toxins (and also the toxons) are not simple bodies, but 

 easily split up into other substances which differ from one another 

 in the avidity with which they combine with antitoxins. Among 

 these derivatives there are found prototoxins, deuterotoxins and 

 tritotoxins, which are here mentioned in the order of the readiness 

 with which they combine with antitoxins, the tritotoxins combining 

 least readily, but all of these combine with antitoxins more readily 

 than do the toxons. 



3. The complication does not stop with this division, but it is 

 probable that every toxin consists of equal parts of two modifica- 

 tions, which behave with antitoxins in the same manner, but which 

 differ in their resistance to destructive influences ; probably this 

 difference is comparable to that existing between dextro-rotatory and 

 levo-rotatory forms of the same compound. 



4. Of these two modifications, one, which may be designated as 

 the a-modification, readily passes into a toxoid. Indeed, this trans- 

 formation begins and frequently reaches completion in the culture 

 medium in the incubator. The complete conversion of the a-modi- 

 fication into a toxoid leaves the substance with only half of its 

 original toxicity, and it may therefore be called a hemitoxin. 



5. The second modification, which is designated as the /3-modifica- 

 tion, varies in stability in the different kinds of poisons, the proto- 

 toxins, the deuterotoxins and the tritotoxins. The /?-tritotoxin is 

 relatively unstable and often undergoes decomposition in the incu- 



• DeiUsche med. Wochenschrifl, September 22, 1898. 



