CARL L. A. SCHMIDT AND G. F. NORMAN 



683 



Since the action of the protective substance appears to be that of a 

 reducing agent, it seemingly follows that eosin hemolysis is a phenome- 

 non involving oxidation. Hemolysis may be wholly prevented by 

 placing the eosin-red cell mixture in a highly evacuated glass tube or 

 by saturating the cells with illuminating gas or hydrogen. These 

 observations are in agreement wdth the statement of Sellards, that an 

 atmosphere of hydrogen is as effective as total darkness in preventing 



TABLE I, 



The Effect of the Addition of Certain Substances on the Hemolysis of Red Cells 



by Eosin. 



Substance added. 



Sodium chloride (control) . 



Valine 



Serine 



Proline 



Cinnamic acid 



Creatinine 



Tryptophane 



Skatole 



Sodium sulfite 



Sodium thiosulf ate 



Ferrous lactate 



Potassium f errocyanide . . . 



Histidine 1 . 

 Histidine 2 . 



Concentration. 



m/10 

 m/10 

 m/10 

 m/10 

 m/30 

 m/30 

 Saturated solution. 

 M /30, M /90 

 m/30 

 m/30 

 m/30 



m/20 



m/20 



Result. 



Complete hemolysis. 



No hemolysis. 



Some 

 hemolysis over night. 

 No hemolysis. 



* Sufficient NaCl was added to each of these solutions to make them isotonic. 



the toxic action of eosin in sunlight. It must be admitted that in 

 certain instances the reducing agent may react with the fluorescent 

 substance and in this way partially inhibit its toxic action. Thus, 

 when sodium sulfite is added to a solution of eosin and the mix- 

 ture is exposed to sunlight, the latter substance is rapidly reduced to 

 fluorescein. 



The action of sunlight in accelerating oxidative reactions is a well 

 known phenomenon. Bilirubin when exposed to sunlight is oxidized 

 to biliverdin (8), many of the vegetable oils are oxidized by light, and 

 the bleaching of the triphenylmethane dyes (9) is a phenomenon in 



