XXII. A CONTRIBUTION TO THE STUDY OF MOLECULAR 

 ADHESION WITH A CONSIDERATION OF ITS FUNC- 

 TION IN VARIOUS BIOLOGICAL PHENOMENA * 



BY DR. GENGOU. 



L 



For some years biologists and bacteriologists have studied both 

 the inorganic and the organic colloidal substances. As we know 

 the majority of the writers consider the sols (hydrosols, etc.), that 

 is to say, the "solutions" of colloidal substances in fluid, as being 

 not true solutions, but ultramicroscopic or microscopic suspensions 

 of colloidal particles in the fluid. In addition to colloidal solutions 

 we have fine suspensions, such as mastic, aqueous gum arabic, etc., 

 which consist of fine particles in a fluid, with the difference that 

 these particles are visible. 



We have learned a great deal about colloidal solutions from 

 studying these fine suspensions, inasmuch as both substances have 

 certain properties in common. We believe also that certain studies 

 of the chemical precipitates which sediment easily are bound to 

 facilitate our knowledge of the various manifestations of colloidal 

 substances. Inasmuch as colloids are probably very fine suspen- 

 sions, it is likely that all transitions between them and the sedi- 

 menting chemical precipitates with large particles, exist. We 

 must admit that all these substances in suspension have certain 

 common properties. It is often easier to work with chemical 

 precipitates than with colloidal solutions, and such a method is there- 

 fore advantageous in studying those properties which are common 

 to both substances. 



Among these common properties the one which we shall consider 

 almost entirely is the power of adsorption. We have long known 

 that certain solid substances in the form of a fine powder absorb 



* This article is a re"sume\ which was kindly furnished by Dr. Gengou, of an 

 article on the subject which appeared in the Archives Internat. de Physiologic, 



Vol. 7, Fasc. 1 and 2, 1908. 



414 



