I2 4 



Immunity 



non was of wide occurrence and had a broad significance, for 

 they discovered that when the serum of 

 one animal was injected into another ani- 

 mal some reaction took place by which the 

 two serums being subsequently brought 

 together precipitation took place. The 

 same was found true of milk. Myers,* 

 Jacoby,f Nolf,| and others showed that 

 the faculty of provoking specific precipi- 

 tins was common to many albuminous 

 bodies albumen, globulin, albumose, 

 peptone, ricin, etc. Kraus in his original 

 communication dwelt upon the specific 

 nature of the precipitation, and was 

 corroborated by Fish, Wassermann, || 

 Morgenroth, and others, and it was shown 

 that the reaction was sufficiently accurate 

 to make possible the differentiation of 

 human and goat's milk. The most im- 

 portant practical application, however, 

 came through Uhlenhuth** and Wasser- 

 man,tf who made use of it for the dif- 

 ferentiation of bloods for forensic pur- 

 poses. 



Uhlenhuth gave rabbits intraperitoneal 

 injections of loc.c. of defibrinated blood 

 at intervals of from six to eight days and 

 found the blood-serum strongly precipit- 

 ant after the fifth. He used such serum 

 for testing the reaction with the bloods of oxen, horses, don- 

 keys, pigs, sheep, dogs, cats, deer, hares, guinea-pigs, rats, 

 mice, rabbits, chickens, geese, turkeys, pigeons, and men. 



The method of making the test is important, as careless- 

 ness of detail will interfere with the accuracy of the result. 

 The blood to be tested is diluted about i : 100, or until 

 it has a feeble red color, with tap water, and then freed from 



*"Centralbl. f. Bakt.," etc., 1900, Bd. xxxm, and "The Lancet," 

 1900, n, p. 98. 



f'Archiv fur exper. Path. u. Pharmak.," 1900. 

 J "Ann. de 1'Inst. Pasteur," 1900, p. 297. 

 "Courier of Medicine," St. Louis, Feb., 1900. 

 ||"Verhandl. d. Kong. f. innere Med.," 1900, S. 501, Wiesbaden. 

 **" Deutsche med. Woch.," 1900 and 1901. 



tf'Samml. klin. Vortr. v. Volkman," Leipzig, Verlag von Breitkopf 

 and Hartel, 1902. 



Fig. 16. Poly- 

 ceptor (Ehrlich 

 and Marshall) such 

 as can be conceived 

 to occur in hemo- 

 lysis and bacterio- 

 lysis where various 

 complements are 

 engaged. a, Re- 

 ceptor of bacterial 

 cell ; b, cytophil 

 group of the ainbo- 

 ceptor; c, dominat- 

 ing complement ; d, 

 subordinate com- 

 plement ; a, /?, 

 com plementophil 

 groups of the am- 

 boceptor, a for the 

 dominating, /? for 

 the subo r d i n a t e 

 complements. 



