10 BIOTIC STRUCTURE AND BIOTIC ENERGY 



The necessity of electrolytes for the possession of osmotic energy 

 by colloids has been shown by the writer, and by Roaf and Adamson 

 and others, and it appears as if the trend of modern work upon the 

 chemistry of colloids was moving towards the view that the attached 

 crystalloid governs the activity of the colloid, and that the two 

 together constituting the cry stallo- colloid make a working pair 

 possessing phasic alterations in association and dissociation, with 

 accompanying varying activities and affinities which lie deep at the 

 base of the peculiar energy discharges of living matter. 



The phasic properties and peculiar energy content of colloids are 

 drawn attention to by that pioneer and master-worker on colloids, 

 Thomas Graham, in his classical papers published in 1864 in the 

 Transactions and Proceedings of the Royal Society, which may be 

 said to have laid the foundation of the study of colloids. 



Even at that early date Graham had realised the importance 

 to the physiologist of the study of the properties of colloids which, 

 as he says, form the active part of all living cells. He draws special 

 attention to the important deductions to be drawn from his re- 

 placement of water in the colloidal form of silicic acid by organic 

 bodies, and states, in 1864, that fat might be carried in the tissues 

 in invisible, apparently soluble form in union with the colloidal 

 proteins. Just now this constitutes one of the lines of modern 

 research, and Graham's chance shot is being verified in a wonderful 

 and remarkable manner. 



Graham also draws attention to the striking similarity of the 

 action of slight amounts of alkali in dissolving gelatinised or pec- 

 tised colloids, such as colloidal silicic acid, and that of ferments 

 upon coagulated proteins, and actually calls this process of solution 

 " peptisation " on account of this resemblance. The colloid 

 after solution still remains in colloidal condition, as shown by the 

 fact that the necessary amount of alkali to give a clear peptised 

 solution is only a small fraction of that which would be required 

 to yield a mono-molecular solution of crystalloidal silicate. Here 

 the colloid evidently passes into solution because of some kind of 

 molecular union with the crystalloid. And each solution aggregate 

 in the peptised solution probably consists of one active crystal- 

 loidal molecule surrounded by and attached by molecular union 

 to several colloidal molecules. 



The fact that colloidal molecules in solution possess a peculiar 

 energy of their own was also appreciated by Graham, who remarks : 



