530 COLLECTED STUDIES IN IMMUNITY. 



If one conducts experiments that have nothing to do with the 

 problem under discussion, further, if the method of these experi- 

 ments is grossly at fault, and it, finally, the results thus obtained 

 are given an utterly false interpretation, it is not surprising that 

 the most fantastic results are obtained. 



Finally Gruber describes one more experiment which he illus- 

 trates by means of a curve. According to him this too demonstrates 

 that my theory is untenable. The experiment shows that the haemol- 

 ysis of ox blood, by means of a certain quantity of specific hsemolytic 

 serum within half an hour, is dependent on the dilution. I need 

 hardly remind my readers that 1 have always laid stress on the chemi- 

 cal nature of the toxin and antitoxin combination. I can assure 

 them that the factor of the degree of concentration has ever been 

 sufficiently regarded. If Gruber will refer to my first study on this 

 subject, " Die Werthbemessung des Diphtheneheilserums," he will 

 find the statement: " that the union of poison and antibody pro- 

 ceeds much more rapidly in concentrated than in dilute solutions/' 

 and further also " that heat hastens the union and cold retards 

 the same." 



The behavior which Gruber describes is all the less surprising 

 since he is dealing with a complex process depending on the action 

 ot the amboceptor-complement combination. How readily this 

 combination is dissociated has repeatedly been pointed out by us p 

 Perhaps Gruber thinks that this experiment is new to me; every 

 one versed in the subject, however, knows that we are here deal- 

 ing with the most commonplace phenomena, with which every beginner 

 is well acquainted. I should like to point out, however, that this 

 phenomenon, namely, that dilution with water inhibits the action 

 of haemolysins, is not at all constant. On the contrary it is limited 

 to those cases in which the affinity between amboceptor and cell, 

 or between amboceptor and complement is relatively slight. If 

 one employs poisons in which the affinity between receptor and 

 cell is great it will be found that within the limits mentioned the 

 addition of water is practically without effect. Thus, in working 

 with cobra venom, I found that a given quantity of this poison 

 exerted exactly the same effect whether the volume of water used 

 was 1 or 15. 



It would lead us too far to enter into all the distortions and mis- 

 conceptions contained in Gruber's polemic. To do this would require 

 almost a complete reprint of all my articles, as well as of many others 



