PRECIPITINS 141 



posed, at the Congress for Internal Medicine, 1900, 

 to use these sera as a means of differentiating 

 albumins, i.e., to distinguish the different albumins 

 from one another, and particularly to distinguish 

 those derived from man from those of other 

 animals. This proposal thus to use the Tchisto- 

 witsch-Bordet precipitins had important practical 

 and theoretical results. Uhlenhuth, Wassermann, 

 Schiitze, Stern, Dieudonne, and others showed 

 that a serum could be produced from rabbits 

 by injecting them with human serum, by means 

 of which it is possible to tell positively whether 

 a given old, dried blood stain is human blood or 

 not. 



Uhlenhuth 1 tested nineteen kinds of blood and 

 only obtained a reaction with human blood upon 

 adding antihuman serum to the series of dilutions. 

 He, moreover, found that human blood which had 

 been dried four weeks on a board could be readily 

 distinguished by means of antihuman serum from 

 the blood of the horse and ox. On the following 

 day Wassermann 2 demonstrated experiments simi- 

 lar to Uhlenhuth's at the meeting of the Physiologi- 

 cal Society, Berlin. Outside of human blood only 

 that of a monkey gave the reaction with anti- 

 human serum. 



1 Uhlenhuth, Deutsche med. Wochenschrift, 1901. xxvii. 



2 Wassermann, A., and Schutze, Berliner klin. Wochenschr., 1901. 

 No. xxviii. 



