108 The Nature of Precipitin Reactions 



constituents of the antisera were next tested, and it was found that a 

 solution of the fibrinogen fraction, and still more of the globulin fraction, 

 precipitated the same constituents as the preceding, but no precipitin 

 was contained in the albumin fraction. The precipitin was therefore 

 precipitated with globulin, but it is not certain whether it was^ simply 

 carried down, or whether it is a globulin itself. Umber also concludes 

 that the precipitins do not afford a means of differentiating the albumins 

 of the same animal. 



Oppenheimer and Michaelis (18, vii. 1902) treated rabbits with ox 

 serum-albumin and found their antiserum to precipitate serum-albumin, 

 having less effect upon pseudoglobulin, none on euglobulin, nor on 

 horse serum-globulin. Globulin-treated rabbits formed precipitin for 

 globulin alone. Landsteiner and Calvo (18, vii. 1902, p. 782) treated 

 rabbits with different components of horse serum, the fractions containing 

 a, fibrinoglobulin and euglobulin, h, pseudoglobulin, c, albumin. The 

 antisera for fraction a precipitated dilutions of all three fractions, the 

 intensity of reaction being in the order a, b, c, being weak in the last. 

 The antisera for fraction b acted similarly, but more on dilutions of b 

 than of a. The antisera for fraction c had no effect in a first experiment, 

 but did have in a second, precipitating both solutions of c and of 

 globulins where the fraction had been reprecipitated. The behaviour 

 of globulins to precipitins was inconstant. The authors conclude that 

 the precipitable substances in serum represent several bodies with 

 different reactions as regards precipitation. The precipitable sub- 

 stances do not act in accordance with known albuminous bodies in 

 serum, in other words, there is no reason to identify the precipitable 

 substance with globulin. Ide (27, vii. 1902, p. 266) injected ox 

 haemoglobin into rabbits, and in confirmation of his pupil Leblanc 

 found the antiserum to precipitate ox haemoglobin solutions, the anti- 

 serum also haemolyzing ox corpuscles. Ascoli (26, Vlli. 1902) treated 

 rabbits with fibrino-, eu-, and pseudoglobulin, serum-albumin, and 

 normal serum. Following a recommendation of Arthus he used S^/o 

 sodium fluoride solution with which to prevent bacterial development 

 in his serum dilutions, which had to be kept at 37° C. during his 

 experiments. He reaches the conclusion that there are qualitative 

 differences in eu- and pseudoglobulin, and serum-albumin solutions 

 made evident by the biological test, and that consequently an anti- 

 serum produced through injection of normal serum contains different 

 precipitins, each of which seizes upon different components in normal 

 serum when it acts thereon. 



