Ether and Energy in Evolution of Matter 17 



While some of the simpler metallic colloids, like platinum, 

 gold, and silver, may be comparatively stable, and may remain 

 in solution for months, others, like lead and iron, soon change 

 into new compounds from contact with the atmosphere. This 

 tendency to undergo change and decomposition is, of course, 

 associated with interchanges of energy, and is true of the great 

 majority of colloids, as contrasted with the usually slower 

 alteration of crystalloids. Hence Spencer, quoting Graham, 

 (7; 16) says: *'The colloid is, in fact, a dynamical state of 

 matter, the crystalloidal being the statical condition. The 

 colloid possesses energia. It may be looked upon as the primary 

 source of the force appearing in the phenomena of vitality." 



With such considerations before us, it behooves us to look 

 further into colloid phenomena. As to size, investigators agree 

 that colloid molecules are greatly larger than the crystalloid; 

 they are incapable of passing, or only slowly pass, through 

 parchment and similar membranes; this incapacity seems to 

 be wholly due to the large size of the molecules, which are 

 stopped in front of the minute interstices of the membrane. 

 Their osmotic pressure is very low; and, beside being relatively 

 unstable, they often start catalytic changes in liquids with 

 which they come in contact. 



One triumph achieved by the ultramicroscope has been 

 the resolution of various colloid substances into discrete mole- 

 cules floating in the solvent liquid. As the water or other 

 solvent is evaporated, these molecules gradually approach 

 each other until, in the firm gelatinous or even hard stage of 

 silicic acid, they may only be separated by water jackets from 

 each other. Measured by the ultramicroscope, the colloid 

 particles of platinum are about 45 /x/x in diameter according 

 to Walker {19: 221). 



As compared, therefore, wiXh true crystalloid solutions, 

 which are perfectly clear, homogeneous, and devoid of visible 

 particles, all colloids show a finely granular or coarse molecular 

 state. But even colloids present themselves under two phases, 

 that have been called the suspensoid and the emulsoid. The 

 former show definite suspended and finely divided floating 



