ON ENZYMES AND LIVING CELLS 101 



alkalies, and the same dependence upon hydroxyl and hydrogen 

 ions, is observable in the case of living cells as has been described 

 above in the case of the enzymes. 



The rate of growth and cell division, and the regularity of. 

 the latter process, are dependent in large measure 'upon the 

 reaction of the medium which bathes and permeates the cell. 

 Solutions of various neutral salts in addition have a marked in- 

 fluence upon cell growth and upon the maintenance of a physio- 

 logical condition of normal metabolism in the cell, but it is the 

 alkalies and acids, and these proportionately to their concentration 

 in hydroxyl and hydrogen ions, which exercise the profoundest 

 influence. 



A normal balance in the ratio of hydroxyl and hydrogen ions 

 must be maintained, or the whole of the metabolism and life of 

 the cell becomes abnormal and morbid. 



The position of pioneer in this subject must be ascribed, as 

 mentioned above, to Sidney Ringer, who first showed the enormous 

 importance of even minute doses of certain inorganic salts in 

 maintaining a normal condition, and proper performance of 

 physiological functions in living cells. 



Ringer, working before the advent .and about the time of the 

 introduction of the modern ionic theory of solutions, did not 

 express his results in the language of that theory, and spoke of 

 " the action of calcium or of lime of potassium or of potash salts," 

 instead of, as in modern terminology, of ;; the effects of molecular 

 concentration of the calcium or potassium ion," and of the effects 

 of acids and alkalies instead of those of hydrogen and hydroxyl 

 ions. But there is no doubt that Ringer thoroughly appreciated 

 that the effects he obtained were due to the one ion of the com- 

 bination he used although he did not speak of it by that name, 

 and that he recognised without naming them as such the antago- 

 nistic action of different ions. 



It is necessary to point out the importance of this early and 

 classical work of Ringer's, because it appears to be in danger of 

 becoming forgotten by modern workers, who often do not refer 

 to him in their account of previous work, and appear to use 

 " Ringer's solution," or modifications of it, with little knowledge 

 of its history, or of the fact that Ringer by its use had shown 

 the all-importance of ions for the maintenance of physiological 

 activity, and had demonstrated the action of sodium, potassium, 



