86 INTIMATE ASSOCIATIONS OF INORGANIC IONS, ETC HARRIS. 



relative concentrations of H and K needed to produce similar 

 effects on frog's skeletal muscle are in the ratio of 1 to 5, i. e. 

 inversely as their ionic velocities." 



And again he writes: 



"So far from it being possible to ascribe the physiological 

 action of various ions to some one factor such as solution tension, 

 valency or ionic velocity, it must be recognized that one and 

 the same ion may exert its influence on different tissues by 

 virtue of different characters or groups of characters. Further, 

 two ions, which from the point of view of one tissue exhibit 

 constellations of properties which are much alike, may present 

 wholly dissimilar aspects towards another tissue." 



Mr. Mines adopts the view that tissues are to be regarded 

 as "emulsoid (hydrophile) colloids." 



These and similar researches a^e of the utmost value in 

 bringing us towards the biologist's great desideratum greater 

 definiteness of conception regarding the living matter itself. 



Our present point of view is that not alone in terms of pure 

 organic chemistry are conceptions of the constitution of proto- 

 plasm to be framed. We are finding we must include in these the 

 non-organic, the non-vital substances whose presence does not 

 indeed constitute life, but in whose absence life cannot be con- 

 stituted. As we have had in the past full demonstation of the 

 importance of the structurally "infinitely little," so at the 

 present time we are having, each day, fresh demonstration of 

 the importance of the chemically infinitely little. 



Dalhousie University, Halifax, Nova Scotia. 

 April 6th, 1912. 



