89 



lifetime may have a certain specificity, as shown by the example 

 of ATP. Secondly: while sugars produce long life only in rela- 

 tively high concentration, glutathione and ATP produced it in a 

 hundred times lower concentrations; this indicates that glucose 



Table II 



LoNG-LiFE Phosphorescence in the Presence of Glucose, 



Glutathione, and ATP in Frozen Solutions of Acridine 



Orange, Rhodamin B, Riboflavine and Quinidine 



Glucose (2%) Glutathione (0.002 Af) ATP (0.002 Af) 



acts by some general physical influence, like the alteration of solu- 

 bility, while the other two substances act by means of some more 

 specific mechanism. 



The example of glucose and alcohol suggests that substances 

 can, roughly, be divided into two groups: those which fit well into 

 the water structure and, in a way, increase order, and, those which 

 do the opposite. It seems likely that it will be found that the sub- 

 stances which play a major role in cell life and are found in cells 

 in an appreciable concentration, belong to the first group. It seems 

 also likely that substances which create disorder are not admitted 

 into the cell by the membrane or may be even pushed out from 

 the ordered intracellular water, suggesting a new theory of perme-^ 

 abilit)'. Possibly, substances which prolong the lifetime of the' 

 excitation of another substance, mediating between this substance 

 and water, also will be found to render these substances more 

 permeable. 



1 



