RELATION OF TOXINES TO ANTITOXINES. 59 



1. The toxine. 



2. The toxone, which kills rabbits suddenly, and guinea-pigs 



after symptoms of illness. 



3. Toxonoids, causing illness in rabbits, but harmless to 



guinea-pigs. 



He also maintains that diphtheria toxine has so great affinity 

 for its antitoxine that the curve of neutralisation of the pure toxine 

 would form a straight line ; the deviations can only be explained 

 by the assumption that parts of it possess different degrees of 

 affinity. These fractions of varying affinity are present in the 

 original poison. 



The theoretical deductions of EiSENBERG 1 are very similar to 

 the conclusions drawn by ARRHENIUS and MADSEN from their 

 experimental results. He, too, is inclined to attribute the neu- 

 tralisation of the poison and antidote to the production of a state 

 of equilibrium, in which an excess of each of the two active 

 components is present, in addition to the firmly-combined neutral 

 compound. He claims, by means of this theory, to be able to 

 obviate the difficulties in the way of accepting the view that only 

 the compound and the excess of one component are present. His 

 argument, however, also rests upon conditions that occur with 

 other poisons than diphtheria, such as those of tetanus poison, 

 hsemolytic complements, and, above all, agglutinines. 



It is extremely probable that in the case of these substances 

 loose combinations may occur with dissociated states of equili- 

 brium. But in the case of diphtheria virus the conditions of 

 combination appear to be the only important factors, which 

 EISENBERG, too, admits to be possible, and that the quantity 

 of components liberated is very slight, as it should be in the 

 case of firmly '-combined compounds. Thus EHRLICH'S arguments 

 are also a sufficient answer to these generalisations, which in fact 

 do not apply to diphtheria virus. 



Thus we cannot predict beforehand what the conditions will 

 be in the case of other poisons. The question as to the influence 

 of the several derivatives on the quantitative relation between 

 toxine and antitoxine must be specially determined for each 

 separate poison. Probably a whole scale of affinities will be 

 found to exist, ranging from loosely combined, readily dissociated 

 compounds, such as appear to be formed by tetanolysine to 

 diphtheria virus. In this connection it may be mentioned that 

 conditions of equilibrium also appear to occur in the case of 

 ricine, in which when neutralisation is nearly complete free 



1 M. Eisenberg, " D. Bindungsverh. zwischen Toxin und Antitoxin," 

 Centralbl.f. Bakt., xxxiv., 259, 1903. 



