382 Medico-Legal 



Ehrlich spoke of precipitins as " coagulins," Wassermann termed them 

 " agglutinins 1 ." Wassermann referred to experiments of his own upon 

 lactosera. With lactoserum for cows' milk he only obtained a pre- 

 cipitation with cows' milk, not with human or goat milk. " Es handelt 

 sich immer urn specifische Korper, je nach der Milchart, welche dem 

 Thier vorher injiciert wurde....Die Eiweisskorper in verschiedenen 

 Thiergattungen sind demnach streng different und verschieden." He 

 added that experiments made with fowl egg-white also gave " in der 

 That specifische Coaguline gegenuber dem Hiihnereiweiss." It is there- 

 fore fully evident that Wassermann recognized the practical bearings of 

 the discoveries of Tchistovitch and Bordet, and credit is due to him for 

 having suggested the use of precipitins in the differentiation of al- 

 bumins of different animals. 



It will be noticed that Wassermann refers to the precipitins, as 

 affording a means of distinguishing the albumins of different animals, 

 irrespective of their being contained in blood or the like, and it is 

 therefore not correct, as he states in a personal letter to me (15. I. '03), 

 strictly speaking, to refer to the precipitin or biological method in blood 

 diagnosis. To be certain that a reacting substance is blood, it is still 

 necessary, in forensic practice, to utilize the ordinary tests for blood, 

 such as that for haematin etc. According to Wassermann the reaction 

 demonstrates the presence of albumins belonging to certain animals, 

 without especially telling us which albuminous substance we are 

 dealing with. 



The medico-legal use of precipitins was almost simultaneously 

 discovered by Uhlenhuth, Wasserinann and Schiitze (see p. 162). 

 Uhlenhuth (7. ll. 1901) considered that the method might have forensic 

 value in the identification of blood stains. He tested 19 kinds of 

 blood and only obtained a reaction with human blood upon adding 

 anti-human serum to the series of dilutions. He moreover found that 

 human blood which had been dried 4 weeks on a board, could be readily 

 distinguished by means of anti-human serum from the blood of the horse 

 and ox. Wassermann and Schiitze (18. II. '01), a few days later, 

 reported having examined 23 bloods, none of which reacted to anti-human 

 serum except human blood and that of a baboon, the reaction in the 



1 I prefer to refer to these antibodies as precipitins for the reason that the term 

 conveys a definite meaning with regard to the appearances observed in their reactions. 

 The term agglutinin has been used with a definite meaning hitherto, and it can 

 only lead to confusion to include precipitins under agglutinins even assuming that 

 the antibodies are identical, which is unproved. The same objection holds for the term 

 coagulins (see p. 17). 



