FURTHER DEVELOPMENT OF KNOWLEDGE 183 



experiments cited by Marks 59 it appears' that the most ineffective 

 complement is obtained when "mid-piece" and "end-piece" are added 

 to the sensitized cells in proportions of 1 to 1. If the proportion of 

 "mid-piece" is increased two or threefold over that of "end-piece," 

 hemolysis is inhibited. This, however, is true only when the two 

 fractions are simultaneously added to the sensitized cells. When the 

 sensitized cells are exposed to the excessive quantity of the "mid- 

 piece" separately, and "end-piece" added later, the effect is one of 

 stronger hemolysis than when smaller amounts are used. It is thus 

 seen that the relations between the complement fractions in hemolysis 

 are very involved. All that we can be sure of is that there are at least 

 two separable parts, that one of these acts directly upon the sensitized 

 cells, forming a so-called persensitized complex and rendering them 

 amenable to the subsequent action of the unprecipitated albumin 

 fraction. 



The many difficulties encountered in the interpretation of the 

 confusing phenomena observed in connection with this problem have, 

 very naturally, led to a corresponding multiplicity of opinion. Most 

 observers at present incline to the opinion that the globulin and 

 albumin portions of fresh serum, separated by Ferrata's or any other 

 of several common methods, represent actually two complement frac- 

 tions. This is not, however, accepted by all workers. Bronfenbren- 

 ner and Noguchi 60 believe that the entire active complement is con- 

 tained in the albumin fraction or so-called "end-piece." They hold 

 that "complement-splitting" by dialysis or other methods is an inacti- 

 vation of end-piece by change of reaction. In their experiments they 

 were able to restore the functional activity of end-piece by the adjust- 

 ment of reaction, either with acid or alkali, respectively, or by the 

 addition of amphoteric substances. The mid-piece activates, they be- 

 lieve, by reason of its amphoteric nature and consequently adjusts 

 any excessive acidity or alkalinity of the medium. They were able 

 to substitute for mid-piece indifferent amphoteric substances such as 

 alanin. Liefmann 61 has been unable to confirm the experiments of 

 Bronfenbrenner and Noguchi, and believes that their results were 

 caused by incomplete splitting of the complement. Incidental to a 

 study of normal opsonins the writer has also repeated the experi- 

 ments of ;Bronfenbrenner without being able to confirm them. 62 



The method of Ferrata for the separation of the two parts of the 

 complement is successful only if dialysis is very thorough and suffi- 

 ciently prolonged to lead to complete precipitation of the globulins. 

 iNeufeld and Haendel 63 have had difficulty in thus separating the 



89 Marks. Zeitschr. f. Imm., Vols. 8 and 11, 1911. 



60 Bronfenbrenner and Noguchi. Jour, of Exp. Med., Vol. 15, 1912. 



61 Liefmann. Weichhardt's Jahresbericht, Vol. 8, 1912. 



62 Zinsser and Gary. Journ. of Exp. Med., Vol. 19, 1914. 



63 Neufeld and Haendel. Arb. a. d. kais. Gesund., 1908. 



