50 LIFE: ITS NATURE AND ORIGIN 



itself to me that the nascent state is allied to or even identical with 

 the colloid state of matters. Just as chemical substances may be either 

 gaseous, fluid, or solid, as some are commonly seen in all states, some 

 only in one, while many which we are accustomed to see in only one 

 may by special experiments be brought into the other forms, so it 

 seems to me probable that all matters, when deposited from solution, 

 or otherwise assuming a solid form, a liquid or gaseous form, have, or 

 tend to have, a colloid and a crystalloid stage, both of which may be 

 well marked, as in silica, or one of which may be more marked than 

 the other, as in uric acid or only one of which may at present be 

 recognized, as in chloride or zinc on one side, in albumen on the 

 other. . . . 



"(2) Hydration. Professor Guthrie . . . throws out a suggestion that 

 the partial dehydration of sulfate of copper has to do with the forms 

 found in the evaporated gelatine solution . . . But . . . sulfate of 

 barium contains no water, yet undergoes the spheroidal change in the 

 most complete way. The same may be said of carbonate of barium, of 

 carbonate and sulfate of strontium, and of cholesterin, all of which 

 readily form spheres. . . . Dehydration, partial or complete, can cover, 

 therefore, only part of the facts. 



"(3) Crystalline Form. I have sought in vain for any indications of 

 any difference in the tendency to sphericity, or in the modifications 

 of spheroidal form assumed by different substances, which might be 

 attributed to their belonging to one or other group of crystalline 

 forms. 



"(4) Relative Solubility. The best spheres are certainly obtained 

 when substances of little or no solubility are deposited by double 

 decomposition; and when a very moderate degree of insolubility is 

 reached, as in triple phosphate, spheroidal forms are only with great 

 difficulty obtained by that process. But by evaporation (Guthrie), and 

 by deposition from hot, concentrated solutions (nitrate of urea, ferro- 

 cyanide of potassium) very soluble matters may be made spheroidal. . . . 



"(5) Influence of the Colloid. . . . The assumption of the spheroidal 

 state, and the throwing off of the crystalline state, are both consistent 

 with the idea of a state of movement possessing the molecules, engross- 

 ing them so fully as to render them insusceptible to attractions by 

 which, being at rest, they would be held and controlled. . . . 



"Graham has spoken of colloid as the dynamic form of matter. The 

 constituents of their large molecules are in a perpetual movement or 

 strain tending to ultimate rest in crystallinity, either by isomeric 

 change or by decomposition. The viscosity characteristic of them in 

 their most perfect state, instead of appearing to me as a peculiarity 

 related to their animal and vegetable origin, is partly due to the size 

 and immobility of their chemical molecule, partly also to their intes- 



