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Scientific Proceedings (129) 



decreased by a further increase in solution concentration. Thus, 

 it would appear that hemolysis by these agents is concerned with 

 surface concentration rather than with solution concentration. 

 If we assume that the time of hemolysis is inversely proportional 

 to the surface adsorption the time of hemolysis can be ex- 

 pressed by the equation 



t — amx-i/n when 



t z= time of hemolysis, 



x = concentration of hemolytic substance, 



m = constant dependent upon the extent of adsorbing surface. 

 a and n are impirical constants. 



This equation, which is the reciprocal of the adsorption for- 

 mula, is graphically similar to the plotted values from experi- 

 mental data which further indicates that hemolysis by surface 

 tension reducing substances is a matter of surface concentration 

 or an adsorption phenomenon. 



141 (2101) 



The fragility of erythrocytes treated with soap and saponin. 



By R. G. GREEN and R. D. EVANS. 



[From the Department of Bacteriology, University of Minnesota, 

 Minneapolis, Minnesota.] 



It was shown by preliminary experiments with hemolytic 

 agents which were active in reducing surface tension that in 

 very low concentration the time of hemolysis was greatly pro- 

 longed. The work here reported has been done to determine 

 if a surface concentration of these substances on red blood cells 

 could be demonstrated when the surface concentration was in- 

 sufficient to cause hemolysis. 



Having determined what concentration of castor oil soap and 

 saponin in 0.9 per cent. NaCl would not hemolyze erythrocytes in 

 a number of hours, red blood cells were placed in solutions of 

 the determined concentration and allowed to stand for varying 

 lengths of time. These cells were then removed and resuspend- 

 ed in 0.9 per cent. NaCl and time-fragility tests performed. We 

 have found that the adsorption of castor oil soap on the sur- 



