136 On the Specificity of Precipitins 



might be worth while to study the reaction given by the bloods of 

 related species, mentioning that he intended to see if there were 

 any similarity of reaction between the bloods of horse and donkey, 

 man and monkey. In his paper of 25, iv. 1901, he first demonstrated 

 reactions amongst a variety of species of egg-albumins which were 

 brought about by an antiserum for the egg-albumin of one species (see 

 further under Anti-egg Sera, Section VI), a fact already indicated earlier 

 by Myers (14, VII. 1900), who found that the antiserum for fowl egg-white 

 acted upon both fowl, and to a lesser degree upon duck egg-white, and 

 that antisera for ox acted on sheep globulin solutions and vice versd. 

 I was able (11, v. 1901) to confirm this with corresponding antisera for 

 ox and sheep blood, showing that slighter reactions were produced 

 by anti-ox serum on sheep blood dilutions and vice versd. On the 

 other hand Wassermann and Schutze (18, n. 1901) stated that the 

 action of anti-human serum was "strong specifisch," except with the 

 blood of a monkey, a fact independently established by Stern (see tests 

 with anti-human serum, Section VI). Uhlenhuth (25, VI. 1901) found 

 anti-sheep serum to precipitate sheep, goat and ox blood, anti-horse to pre- 

 cipitate horse and donkey blood, anti-human to precipitate human and 

 monkey blood. In my paper of 1, vn. 1901, in view of the results then 

 obtained, I stated that the " precipitins are specific, although they may 

 produce a slight reaction with the sera of allied animals." In view 

 of the very limited number of bloods examined by most authors, it seemed 

 to me altogether premature, as some had done, to make any broad 

 generalizations. For this reason, I began early in 1901 to collect 

 as many bloods as I could from all classes of animals. It was 

 as important to do this from the medico-legal as from the zoological 

 standpoint, and in presenting the results given in this book I am safe 

 in saying that they constitute the first scientific demonstration, on 

 general lines, of the specificity or relative specificity of precipitins. 



Although I have been unable to consult the original paper by 

 Schirokich (21, vn. 1901), it would appear that he also noted the action 

 of antisera on certain non-homologous bloods. He put a time limit upon 

 the reaction for the reason that he observed an opalescence, as he terms 

 it, after 4 5 hours, when he added anti-human serum to dilutions 

 of ox, goat, hog, horse, camel, cat, guinea-pig and rabbit sera, a 

 precipitum being formed after 24 hours. I do not know with what 

 dilutions he worked, but should think that they were concentrated, for 

 it does not seem impossible to me that some of the deposits may have 

 been due to matter suspended in the antiserum itself, which in the 



