SECTION IX. 



ON THE PRACTICAL APPLICATION OF THE PRECIPITIN 

 REACTIONS IN LEGAL MEDICINE, ETC. 



1. Antisera in the Examination and Identification of Bloods 

 and Blood-Stains. 



THE reactions given by specific haemolysins and agglutinins possess 

 scarcely any value medico-legally for the reason that to make such tests 

 a large number of intact blood corpuscles must be in suspension. The 

 use of the haemolysins medico-legally was first suggested by Deutsch 

 (see p. 41) who claimed that they might even be used upon dried 

 corpuscles. There are certainly grave sources of error in the method, as 

 compared to what we find when using precipitins. 



The specific character of precipitins was already indicated by Kraus 

 for bacterio-precipitins and by Bordet, Fich, and Morgenroth, in their 

 work on Lactosera. It was recognized by Ehrlich, who refers in his 

 Croonian Lecture, to still unpublished experiments of Morgenroth upon 

 lactoprecipitins. Although at the time very few data had been collected 

 regarding the precipitins, the assumption seemed justified that they 

 would prove to possess similar specific characters to the haemolysins 

 and agglutinins. Ehrlich's paper was read before the Royal Society, at 

 a meeting which I attended on the 23rd of March, 1900. 



Subsequently, Wassermann (18 21 April, 1900)' brought the 

 question of specificity into greater prominence, speaking of the reaction 

 as " eine strong specifische Methode " which permits us " iiber die 

 Stellung verschiedener Eiweisskorper Aufschluss zu geben : namlich 

 durch die Bildung der streng specifischen Agglutinine in Thierkorper 

 die wir seit Jahresfrist kennen, und die mir noch nicht gcnug gewiirdigt 

 scheint." He refers to the work of Bordet on lactosera. Bordet, and 



1 I am indebted to Professor Wassermann for a manuscript copy of the paper cited, 

 the original being inaccessible to me. G. H. F. N. 



