98 ANAPHYLAXIS AND ANTI-ANAPHYLAXIS 



we know — that is to say, it is formed b}'^ the com- 

 bination of toxogenin with antigen; we thus have 

 the chemical reaction : 



Toxogenin+antigen=apotoxin . ' ' 



So much for the genesis of this chemical poison 

 apotoxin. As to its properties, Charles Richet 

 remarks that it is almost impossible at present to 

 pursue the studj' of apotoxins further ; that the 

 various apotoxins are probably substances extremely 

 similar, if not identical; that they are rapidly 

 destroyed and cannot accumulate in the blood. 



In his identification of apotoxins with the ana- 

 phylotoxins of Friedberger — to the subject of which 

 we shall return presently — Richet has enabled us 

 to penetrate still farther mto the foundation of his 

 conception of anaphylaxis. 



It was at the beginning of 19 lo that the idea of 

 anaphylotoxin was first promulgated in microbiology.^ 

 It is a curious fact that the theory of Friedberger 

 had ihe good fortune, rather rare in matters of science, 

 to rally at once the forces of the great majority of 

 bacteriologists. 



According to Friedberger, the anaphylactic anti- 

 body is none other than the antibody precipitin. 

 At the time of the second injection this antibody 

 combines with the antigen and gives rise to a pre- 

 cipitate. It is not, however, the precipitate itself 

 which directly gives rise to anaphylactic sj^mptoms, 

 but a new substance which is formed at the expense 

 of the precipitate and the complement of the circu- 

 lating blood. This is the substance to which Fried- 

 berger has given the name of anaphylotoxin. 



What was particularly fascinating in this theory was 

 the fact that one was not led to waste time over abstrac- 

 tions. All the postulates were liable to immediate 

 1 Zeitschr. f. Immunitdtsf., I. Orig., iv., p. 636, 1910. 



