WATER 129 



that adsorption becomes a factor of the great- 

 est weight; for, other things being equal, 

 the total force of surface tension in a system 

 is proportional to the area of surface. Under 

 these circumstances dissolved substances are 

 no longer distributed with any approach to 

 equality or regularity in the system, but they 

 collect at the surface in very great quantities, 

 and in the most irregular manner. 



Now of all known physical structures there 

 is none which rivals protoplasm in its fine 

 complexity, and adsorption is therefore un- 

 questionably a prominent agent in deciding 

 its physico-chemical constitution. Moreover, 

 adsorption influences and complicates almost 

 every process of chemical physiology, for no 

 product of life is without its colloids, i.e. sub- 

 stances which are finely divided and there- 

 fore endowed with great surface areas. In 

 truth colloids are probably quite essential to 

 fine complexity, and so to every conceivable 

 form of life. 1 



The evidence for this universal importance 



1 "Eines aber rnochte ich behaupten, welches auch iminer 

 die stoffliche Zusammensetzung jener Lebewesen (living 

 organisms in another world) sein mag : es miissen Kolloide 

 sein. . . . Welcher andere Zustand, ausser dem Kolloiden, 

 konnte derart veranderliche, derart plastische Formen bilden 

 und ware doch im stande, diese Formen, wenn nbtig, unver- 

 anderlich zu wahren." — Bechhold, I.e., p. 194. 



