CHAPTER VIII 



DISPERSE SYSTEMS 



COLLOIDS THE RESERVOIRS OF ENERGY 



' The properties of colloidal solutions can be most efliciently inquired into 

 by application, as far us possible, of the same views and methods as those generally 

 applied to true solutions." S/>HENSEN. 



IN Chapter V. colloids were mentioned as a series of substances 

 which when dissolved in water have a lower osmotic pressure 

 than would be expected from their molecular weight. The reason 

 for this, deduced from the colligative properties of their solutions, 

 is that in water they form aggregates or colloidal particles of extra- 

 molecular size. 



The effect of this is enormously to increase the effective surface 

 oj the solvent. Therefore the phenomena of surface tension and 

 surface adsorption will be marked. 



The appended table makes clear the enormity of the increase 

 in effective surface that takes place when a sphere is divided into 

 a large number of small shot and these are, in turn, divided into 

 particles of colloidal size. 



TABLE IX. 



INCREASE IN SURFACE OF A SPHERE WHEN ITS RADIUS is 



DECIMALLY DIVIDED. 



B,B. 



05 



