PROPERTIES OF ANTISENSITIZERS. 301 



as a solution of albuminous substances, precisely as the serum 

 of animals vaccinated with milk sensitizes milk; in other words, 

 confers on certain of the constituents of milk a power to ab- 

 sorb alexin.* Gengou has demonstrated the interesting fact that 

 " anti-albuminous sensitizers/' similar to antimicrobial or anti- 

 hematic sensitizers, may be obtained, which have a similar power of 

 fixing alexin when united with the antigen. Gengou proved the 

 existence of such sensitizers, not only in the serum of animals im- 

 munized against milk, but also in the serum of animals treated 

 with an alien serum. Such an antiserum plays an obvious role 

 in Morgenroth's experiments. We are justified in supposing, then, 

 that the alexin absorption is brought about, not by a union of anti- 

 sensitizer with sensitizer, but simply by certain sensitized albumin- 

 oids of the rabbit > ox serum. 



Morgenroth's conclusion, therefore, is not acceptable in the 

 present state of our knowledge. As far as we are concerned, the 

 theory of complement deviation by amboceptor (sensitizer) is a 

 myth. We have already stated that an identity of receptors with 

 antibodies cannot be admitted. It is not only incompatible with 

 our own results, but receives no experimental confirmation from 

 the work of Pfeiffer and Friedberger, who are zealous upholders of 

 Ehrlich's theory. 



We may note in passing that Morgenroth has not noticed in his 

 experiments that his antisensitizer can cure already sensitized cor- 

 puscles. In this his result differs from our own; but we used a 

 different antiserum. The question, however, properly arises as to 

 whether the lavish use of normal salt solution (which, as we have 

 seen, tends to annul corpuscle protection to a great extent and 

 should therefore be, as much as possible, eliminated from hemolytic 

 experiments f) has not affected the accuracy of this author's obser- 

 vations. 



Let us now consider as briefly as possible Ehrlich and Morgen- 

 roth's ideas on antisensitizers as stated in their sixth memoir on 

 hemolysis. 



These authors employ an immune serum from rabbits immu- 

 nized against ox blood. They find that this serum gives hemolysis 

 with various alexins and particularly with those of the guinea-pig 

 * See Gengou, p. 241. f See also Gay, p. 333. 



