ANTITOXINS 2 5 



take place. The results were complicated andEhrlich 

 found it convenient to express them graphically in 

 the form of the so-called "toxin spectra. " Without 



10 20 30 40 



Toxon 



70 80 90 100 



150 



200 



FlG. 2. 



going much deeper into the subject the point maybe 

 illustrated by the appended diagrams or " spectra." 



Fig. 2 shows the simplest conceivable diphtheria 

 poison. In this case the following values would 

 be obtained. 



# cc poison (100 fatal doses) + f antitoxin 

 units = o, i.e. absolutely neutral. 



# cc poison + iffft = Free toxon. 



# cc poison + *{} = Free toxon. 



That is to say, if the proportion of antitoxin added 

 was Mti of the amount required for complete 

 neutralization, it would be found that the poison 

 thus uncombined was much less, and differently 

 toxic than a corresponding amount of the original 

 toxin. It was found that these fractions possessed 

 a rather constant though low degree of toxicity 

 with characteristic action. This consisted in the 

 production of some local oedema, followed by a 

 long incubation period, and finally the develop- 

 ment of cachexia and paralysis. Ehrlich believes 



