Anti-Horse and Donkey Sera 195 



790 Tests with Anti-Horse Serum. 



Four antisera were used in the tests noted on p. 194, the antisera having 

 been obtained from as many rabbits treated with the serum of horses 

 slaughtered at Cambridge. Three of the antisera were powerful, one of 

 moderate strength, giving, when standardized, a precipitum of "008 c.c. 



The reactions with anti-horse serum, and with the antisera for 

 the donkey and zebra, are practically in accord. The large reactions 

 are in all three cases confined to equine bloods. In the case of the 

 last two antisera, a time limit was put upon the reactions recorded, 

 those only being included which took place within 40 minutes. For 

 this reason the effects of these antisera seem more limited, although 

 the difference is trivial. 



Although the reactions with the bloods of Equidae are put down as 

 equal, there is a very distinct difference both with regard to the time 

 in which they take place, and the amount of precipitum formed. 

 Anti-horse serum acts more rapidly on horse blood than upon the 

 others, anti-donkey more rapidly upon that of the donkey, anti-zebra 

 more rapidly upon that of the zebra. In the quantitative tests to be 

 reported in Section VII. these differences are stated in figures, and 

 are dwelt upon more in detail. 



(10) Tests with Anti-Donkey Serum. 



This antiserum was first obtained by Uhlenhuth (25, vn. 1901) who 

 tested 24 bloods therewith (see list p. 172) and found it only to react 

 with 2 bloods, those of the donkey and horse, less with the latter. 



94 Tests with Anti-Donkey Serum. 



The following tests were made on one day, and with one antiserum 

 obtained from a rabbit which had been treated with the serum of Equus 

 asinus. Only the reactions occurring within 40 minutes are recorded. 

 The antiserum was fairly powerful, giving a precipitum of about O'Ol c.c. 

 when standardized. 



The tests on the bloods of Ungulata and Cetacea are included in 

 the extended tables at the end, but not the others, as they were made 

 in such limited numbers. Only one test on Ungulata is not included in 

 the tables at the end, the test having been made on a fluid ox-serum 

 (1, 1. 1902) not included amongst the numbered samples The following 



13-3 



