THE COLLOID-CHEMISTRY OF SOAPS 7 



in which they are encountered in the ordinary processes of the 

 soap manufacturer, represent typical colloid-chemical systems. 



The relationship between the older physico-chemical views, 

 which proved that soaps under certain circumstances act as 

 " normal electrolytes," and the insistence of later observers that 

 thfv are colloids will become clearer as we proceed. Since the 

 "soaps" ordinarily li-Mi>s<d are mixed soaps, and since the 

 properties of such mixed systems are in themselves dependent 

 upon the nature of the soaps entering into these mixed systems, 

 il best to begin by an investigation of the physico-chemical 

 properties of the pure soaps themselves. 



1 1 is well, for this purpose, to list the fatty acids of the tech- 

 nical and theoretical chemists. This is done in the following 

 table which is taken from J. LEWKOwrrscH. 1 Those fatty acids 

 of the various categories which receive special study in the suc- 

 ceeding pages are printed in bold face. 



TABLE I 



I. ACIDS OP THE SERIES CH*,Oi. ACIDS OP THE ACETIC SERIES 



>J LBWKOWITBCB: Oiln, Fata and Waxes, 5th Ed, 1. Ill, London 

 (If!*) 



