ANAPHYLAXIS 387 



Pick and Yamanouchi, 7 whose extensive investigation cannot be 

 fully reviewed here, were unable to obtain such a separation; in 

 fact, they conclude that the same substances which sensitize are also 

 toxic, and, working^with a large variety of methods, find that both 

 the sensitizing ^a~nd toxogenic properties of proteins show no differ- 

 ences either in chemical condition or in resistance to chemical agents 

 or heat. 



The work of Pick and Yamanouchi, however, was done with 

 rabbits and, therefore, as bearing on the theory of Gay and Southard, 

 the work of Doerr and Russ 8 is more directly to the point. These 

 workers using guinea pigs, and both horse and beef sera, obtained 

 results which are practically diametrically opposed to those of Gay 

 and Adler. They found that the euglobulins, obtained by % satura- 

 tion with ammonium sulphate, are the most strongly sensitizing and, 

 at the same time, the most toxic of the fractions of the sera. As 

 saturation with the salt is increased, the proteins which come down 

 decrease progressively and in parallelism, both as regards the power 

 to sensitize and the faculty of exerting toxic action on second injec- 

 tion. The albumin, which finally comes out on total saturation, is 

 devoid both of sensitizing and of toxic properties. Similar results 

 were obtained by Doerr and Russ with the precipitation of serum 

 proteins with CO 2 . 



The weight of evidence, therefore, seems to point against a chem- 

 ical separation of the two functions in the antigen. 



Besredka's contentions in favor of such a separation were based 

 chiefly upon a difference in resistance to heat. 



His experiments showed that the sensitizing properties of serum 

 are not lost even if it is heated to 120 C., while the toxogenic 

 powers are destroyed by much lower temperatures. The results of 

 Besredka as to the differences in thermostability between the two 

 properties have found confirmation by Kraus and Yolk 9 and others, 

 and there can be little doubt that the sensitizing function is extremely 

 heat-resistant, since this has also been shown by Wells, 10 Rosenau 

 and Anderson, and many others. However, researches by Doerr and 

 Russ, 1 * and notably by Wells, have shown that, though not destroyed 

 by high temperatures, even moderate heating markedly diminishes 

 the sensitizing function, and that larger doses have to be given as 

 the temperature is increased; and since the smallest quantities of 

 antigen necessary for inducing shock at the second injection must be 

 anywhere from 100 to 1,000 times as large as the smallest sensi- 

 tizing doses, it is quite likely that a combination of such conditions 



7 Pick and Yamanouclii. Zeitschr. f. Immunitatsforschung, 1, 1909. 



8 Doerr and Russ. Zeitschr. f. Immunitatsforschung, Vol. 2, 1909. 



9 Kraus and Volk. Zeitschr. f. Immunitatsforschung, Vol. 3, 1909. 



10 Wells. Jour. Inf. Dis., Vol. 5, 1908. 



11 Doerr and Russ. Loc. cit. 



