136 PROPERTIES OF ANTI-SERUM TO SERUM 



and precipitin) in relation to the absorption of complement, 

 and comes to the conclusion that these unite in variable 

 proportions. He also emphasizes the parallelism between 

 the amount of precipitate formed and the amount of com- 

 plement (alexine) absorbed. Friedberger 1 gives an account 

 of his observations on this subject, one of the most important 

 of which is that, while most of his anti-sera have shown 

 deviating powers similar to those recorded by others and 

 observed by ourselves, he has obtained an anti-human 

 serum which gives a deviation in the extraordinarily minute 

 amount of 0-000,000,001 c.c. Even 0-000,01 c.c. of human 

 sweat produced a recognizable fixation of complement with 

 this anti-serum. This is further referred to below. The 

 subject is critically reviewed by Liefmann 2 especially in 

 relation to precipitum-formation on the one hand and 

 amboceptor-action on the other. He considers that a satis- 

 factory explanation of the fixation of complement is not 

 yet possible. 



It thus appears that a number of questions, both of 

 practical and of theoretical importance, are opened up by 

 these investigations and we shall deal with some of them in 

 this section. 



Methods. The method which we used for preparing the 

 anti-serum is that usually followed in precipitin work, viz. 

 the intra-peritoneal injection of a particular serum in 

 varying doses at suitable intervals of time. The anti-serum 

 before being used is of course heated at 55 C. to destroy its 

 complement. We have used three anti-sera obtained from 

 the rabbit, which act on the serum of man, the ox, and the 

 guinea-pig, respectively, and one from the guinea-pig acting 

 on rabbit's serum. We may conveniently represent the first 

 of these anti-sera as anti-serum rabbit v. man, and so with 



1 Friedberger, Deutsche med. Wochenschr., 1906, p. 578. 

 8 Liefmann, Berlin, klin. Wochenschr., 1906, p. 448. 



