Anti-Horse Serum 193 



several observers since, have prepared this antiserum. In a series of 

 24 bloods tested by nie and reported in my preliminary note of 11, v. 1 901, 

 only horse serum was found to react to its antiserum. Numbers of 

 tests were reported on in my subsequent papers, wherein it Avas 

 stated that the only other blood to react was that of the donkey. 

 Uhlenhuth (25, vii. 1901) reported having tested 24 bloods with anti- 

 horse serum (see list p. 172) and he found no other bloods outside those 

 of the horse and donkey to react. Schiitze (6, xi. 1902, p. 805) found 

 this antiserum to precipitate spermatozoa solutions of the horse, but not 

 those of man, and ox. Uhlenhuth (7, xi. 1901) suggests the use of this 

 antiserum for the detection of horse-meat in sausages (see under practical 

 applications), and, using the test on meats, Notel (13, III. 1902) found 

 horse and donkey meat indistinguishable. Kister and Wolff (18, xi. 1902, 

 pp. 414 — 416) published seven tables of tests made by them with anti- 

 horse serum upon 5 bloods. They do not state whether they were all 

 conducted with one, or with several antisera, so it is to be presumed 

 that they used one, which they say " surprised " them by the general 

 reactions which it gave. I have no doubt, in view of my own results, 

 that Uhlenhuth is right in stating that these authors probably had 

 to deal with what is well described as a " milky antiserum " (see p. 72), 

 for their results are somewhat anomalous. Possibly their antisera were 

 preserved with chloroform (see p. 76). They tested the blood of the 

 horse, pig, ox, sheep, and man. On adding antiserum in the proportion 

 1 : 5 blood-dilution (1 : 10 to 1 : 320) all the bloods clouded, the greatest 

 clouding occurred with horse blood, where a large deposit soon formed. 

 Deposits did not occur in the other bloods (except man, tests of 1 : 10 

 and 1 : 40). When the amount of antiserum added was less than 1 : 10, 

 1 : 30, 1 : 50, the reactions amongst non-homologous bloods took place 

 more and more slowly, all the bloods outside that of the horse practically 

 ceasing to react with tests of 1 : 100. Beginning with their tests of 

 1 : 5, and following the series of increasing amount of dilution to which 

 antiserum was added to 1 : 100, we find that the blood of the pig first 

 ceased to react, then that of man and ox. Strong sheep blood dilutions 

 still gave clouds with antiserum added in the proportion of 1 : 100, the 

 clouding only appearing after two hours ; though the homologous horse 

 serum reacted in five minutes. Next to horse, most positive reactions 

 were obtained with man. These results are entirely in disaccord with 

 mine and others. 



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