NEUTRALISATION OF H^EMOLYSINS 1 7 1 



higher concentrations of blood) it is somewhat greater 

 than that of the stronger bases, at least after a prolonged 

 time of reaction (cf. p. in). This seems to indicate that 

 some compound is formed, so that the equivalent quan- 

 tities act to the same degree, but that the ammonia com- 

 pound is to some degree hydrolysed, which causes the 

 deviations. 



Acids also destroy the red blood-corpuscles, but this 

 phenomenon has an appearance somewhat different from 

 the haemolysis by means of bases. Following the action 

 of the alkalies and also of the lysins of bacterial origin, 

 the fluid surrounding the blood-corpuscles takes up their 

 intensive purple colouring matter and assumes the charac- 

 teristic red colour of blood. The acids, on the other hand, 

 alter the colouring matter, so that the fluid becomes dark 

 brown, and after shaking the foam persists often for forty- 

 eight hours or more. This indicates a coagulating influ- 

 ence. With lower degrees of haemolysis by acids the fluid 

 has, however, also a reddish tint. At the same time a 

 strong agglutination of the blood-corpuscles is perceptible. 

 At higher concentrations large clumps are formed, remind- 

 ing one somewhat of the flocculent precipitates of alumin- 

 ium salts mixed with an alkali. The degree of haemolysis 

 by a strong acid is about as pronounced as that of three 

 to four times the equivalent quantity of a strong base. 

 Equivalent quantities of different acids (hydrochloric, sul- 

 phuric, oxalic, tartaric, citric, and acetic) act nearly to the 

 same degree, the weaker acids (for instance, acetic acid) 

 act a little slower than the stronger ; and extremely weak 

 acids, as boracic acid, exert no appreciable haemolytic 

 action (the same is probably valid for extremely weak 



