122 



Scientific Proceedings (66). 



liminary report, it was found that vaso-tone efficiency was 50 

 per cent, greater at 68° than at 86°. It is believed that this test 

 will measure with reasonable accuracy the efficiency of the 

 splanchnic vaso-tone and that this is an important indication of 

 the efficiency of a body and related closely to vitality. It is 

 realized that the test does not measure other important factors 

 of physical and mental efficiency, and will not, for instance, reveal 

 the structural condition of the heart. It does, however, open a 

 new field for the measurement of the results of work calculated to 

 improve physical condition. 



74 (1006) 



On the preservation in vitro of living erythrocytes. 



By Peyton Rous, M.D. and J. R. Turner, M.D. 



[From the Laboratories of the Rockefeller Institute for Medical 



Research.] 



The length of life of the functioning red blood cell is not 

 known, but there is indirect evidence that it is several weeks at 

 least. A priori one might suppose that if these elements were 

 kept in the cold outside the body their period of survival would be 

 much longer. But as a matter of fact in citrated plasma or 

 defibrinated blood the erythrocytes of many species begin to 

 break down within a week or ten days; and washed erythrocytes 

 in normal salt solution or Ringer's fluid do not last even so long. 



In previous papers we have shown that the early hemolysis 

 of washed erythrocytes is attributable in large part to injury 

 during washing; and that this injury can be prevented by the 

 presence of a very little gelatin in the wash fluid (i/8th of 1 per 

 cent.). But even when protected during washing the erythrocytes 

 do not remain intact in vitro nearly so long as they are supposed 

 to in the circulation. We have addressed ourselves to the problem 

 of their preservation. 



For reasons which need not here be entered into, our first 

 experiments were made with solutions of inorganic salts to which 

 non-protein colloids were added. But it was found that though 

 gelatin will protect red cells against injury during washing it has 



