216 CHEMISTRX OF THE IMMVSITY REACTIOXS 



fused as do the salts. Since there is no escape of hemoglobin in such 

 a salt solution, it is evident either that the stroma is not permeable 

 to hemoglobin, or else the hemoglobin is in some way attached to or 

 combined with the stroma. Again, if the corpuscles are placed in a 

 solution of salt more concentrated than their own fluids, water es- 

 capes and the corpuscles shrink; as no hemoglobin escapes with the 

 Avater, it is evident that the stroma is not permeable to hemoglobin 

 when intact. Because of the resemblance of the process of hemolysis 

 to the rupture of plant cells with escape of their contents when they 

 are placed in distilled water, it might be assumed that hemolysis is 

 largely a physical matter, but if a red corpuscle in an isotonic solu- 

 tion is cut into pieces, the hemoglobin does not escape, indicating 

 that its structure is quite dissimilar to that of the simple vegetable 

 cell, and that there is some union of stroma and of hemoglobin, 

 whether a physical or a chemical union. ^^ ]\I. H. Fischer ^° interprets 

 hemolysis as a separation of lipoid-protein stroma and adsorbed hemo- 

 globin, which process can be duplicated experimentally with a com- 

 bination consisting of a corresponding solid hydrophilic colloid, 

 fibrin, and a hydrophobic colloid dye, carmine; this artificial combi- 

 nation behaves exactly like a corpuscle to simple hemolytic agents.^'"' 



Repeated alternate freezing and thawing is another physical means 

 of bringing on hemolysis. Heating to 62°-64° C. causes hemolysis 

 of mammalian corpuscles; in cold-blooded animals this seems to occur 

 at a slightly lower temperature. 



Some chemical agents are capable of liberating hemoglobin, even 

 when the corpuscles are in isotonic solutions. The ordinary salts 

 of serum, of course, do not have this property, but annnonium salts 

 are strongly hemolytic. The chemical agents that dissolve red cor- 

 puscles seem to be those that have the power of penetrating the 

 stroma. Ammonium salts and urea penetrate the coii^useles freelj' 

 and cause hemolysis. Sugar and NaCl seem not to penetrate the 

 corpuscles, and therefore do not produce hemolysis. Of the perme- 

 ating substances, there seem to be two types : one, like urea, does not 

 produce hemolysis when in a solution of NaCl isotonic with the serum ; 

 the other, like ammonium chloride, is not prevented from producing 

 hemolysis by the presence of NaCl.-° 



18 Stewart (Jour, of Physiol., 1890 (24), 211) found that in hemolysis by 

 pliysioal means or under the influence of servuns, tliere is no marked increase 

 in the electrical cfmductivity, but luMnclysis liy sapoJiin and by water causes an 

 increase of conductivity, presumahl.v liccaiisc of llie escajjc of electrolytes; cor- 

 roborated by A. ^^'oelfei, Biocliem. ,Jour., 1908 (3), 140; see also IMoorc and Roaf, 

 ibid., p. 55. 



loKolloid Zeit., 1909 (5), 14G. 



ifa Conccrnin<r the influence of TT-ion concentration on liciiiolvsis sec Walbum, 

 Biocheni. Zeit., 1914 (6.3), 221. 



-0 Ilainbur<,'er, in his book. "Osmot isclier l^ruck iiiid loiiciiiclnf."" reviews ex- 

 haustively tlie physical chemistry of hemolysis. The followiiiLT is his summary 

 of the ])cinicability of red cor[niscles by various sulistaiiccs : 



