642 



pro port ion to their weight. The coipiiseles had always been freed 

 from sernni by cenfrifuging and washing them with a saltsobition. 

 After that they were digested for at least half an hour with the 

 antiserum which was beforehand heated to 56°. As, except for a 

 single exception, homologous (rabbits) serums were always used for 

 this aim, the washing away of the antiserum was not necessary 

 in my experiments, and consequently this was not done. Attention 

 was always paid to all the amboceptor being also absorbed. 



In order to find out all about the rapidity of the production of the 

 amboceptors, the rabbits were bled fiom the earveins every two or 

 three days. (Always little, Va ccm. at the utmosil The serum which 

 was in this way obtained, was heated to 56° for iialf an hour. 

 Tliat is how no allowance was made for the appearance of thermo- 

 labile amboceptors.^) However, as appears from Thiele and Embleton's 

 wiiting, these are never verj- numerous, and they soon disappear. 



The rate of the amboceptor of the various rabbitserums of one 

 day was always defined wirli the same Guinea pigserum so that 

 the numbers are mutually to be compared. As unity of amboceptor 

 a serum was taken, 1 ccm. of Avhich together with Vio ccm. com- 

 plement (fresh guineapigserum) was able to solve 1 ccm. of a 5 7^, 

 suspension of the corpuscles in question, in half an hour at a tem- 

 perature of 37°. 



In the following list the ^.-rabbits have been injected with non- 

 sensitized, the .fi.-rabbits witli weakly sensitized, the C.-rabbits with 

 strongly sensitized red cells. The bloodquantity is unthinned blood; 

 so for 1 ccm. 20 unities amboceptor are equal to 1 dose. 



I. 



Subcutaneous injection of sheepblood IV2 ccm. per k.g. weight. 



A nonsensilized 



B sensilized with 6.6 dose | Strength of the sensitized serum: Vsooo- 



C , „ 100 „ ( With C all was also absorbent. 



A 



rabbit after 5 days after 7 days after 10 days after 12 days after 14 days 



121 Vio Vioo Vsoi ^'soo ^'5 nearly 



122 



123 



124 



125 Vsn nearly '/ann '/«no ^.inn "/500 



^) Thiele and Embleton, Z. f. Immunitatsforschung, XX, p. 1. 



