Human Red Cell Instability and Senescence 227 



(1954), as are the death rates of the cells. The diffusion was 

 calculated from the formula given by Einstein (1926), 



D 



RT 



67a]r 



where D = the diffusion rate, T the absolute temperature, R the 

 gas constant, tq the viscosity of the medium, and r the radius 



HAEMOLYSIS 



20 



-20 -40 -60 

 TEMPERATURE CO 



80 



Fig. 8. The relative rates of diffusion, glycolysis, spon- 

 taneous haemolysis and death of red cells at temper- 

 atures between +40° and —78-5°. The values indi- 

 cated for temperatures above 0° are for aqueous media, 

 below 0° sufficient glycerol was always present to main- 

 tain the cells in liquid suspension. 



of the diffusing molecule. For a given molecular species this 



T 



relationship indicates that D is proportional to — . The 



relative rates of diffusion shown in the diagram are for the 

 values appropriate to the glycerol concentrations and tem- 

 peratures used. The viscosities of glycerol solutions at 



