102 



COLLECTED STUDIES IN IMMUNITY. 



which the anti-immune body is replaced by the same amount (0.5 cc.) 

 of inactive normal goat serum. The degree of solution is shown in 

 Table V. 



TABLE V. 



From these figures we see that a single solvent dose becomes 

 available for combination with the red blood-cells only after eight 

 times the solvent dose has been added, and that a triple dose is com- 

 pletely neutralized, i.e., prevented from combining with the blood- 

 cell. The control test shows that 0.5 cc. of a normal inactive goat 

 serum does not prevent the combination of a single solvent dose of 

 mmune body (0.00125 cc.). The sediment in this case is competely 

 dissolved on the addition of complement. 1 By this experiment the 

 inhibiting substance is definitely characterized as an anti-immune 

 body. The following example will show the exact quantitative 

 relation of this anti-immune body. 



Each 0.4 cc. inactivated serum (anti-immune body) of the goat 

 treated with immune body are mixed with the given amount of 

 inactive serum (immune body) of a rabbit treated with ox blood. 

 The specimens are made up to the same volume by the addition of 

 salt solution, kept at room temperature for half an hour, and then 

 mixed with 1 cc. of a 5% suspension of ox blood, and with 0.15 cc. 

 normal guinea-pig serum (complement). A control test is made in 

 which normal inactive goat serum is used instead of the anti-immune 

 body. (See Table VI.) 



1 We should like to remark that in the course of numerous experiments 

 Tve have now and then found normal goat sera containing slight amounts 

 of an anti-immune body acting on the immune body of rabbits treated with 

 ox blood. This is to be brought into connection with the law (see also Neisser- 

 1. c.) that the artificially produced antibodies frequently represent only an 

 increase of normal functions. 



