112 SOAPS AND PROTEINS 



are of the opinion that such a change does occur and that it is 

 partly responsible for the phenomena observed in these colloid 

 systems. 



BOTAZZI and VICTOROW hold that the addition of alkali to 

 their dialyzed, " acid soap " leads to the formation of neutral 

 soap " which splits hydrolytically. The molecules polymerize 

 with the formation a true colloid solution containing micellae and 

 ' colloid ions,' which then lead to an increase in viscosity because 

 the water of the system is held more firmly through hydration 

 or imbibition.' 1 



MrBAix and TAYLOR, V while originally insistent that their 

 studies " undoubtedly prove, in opposition to the view of KRAFFT, 

 that the normal soaps in concentrated solution are not colloids," 

 conclude later, 2 and more correctly we think, when working with 

 sodium palmitate (at 90) in the presence of sodium hydroxid, 

 that they have in hand systems " in reversible equilibrium con- 

 sisting of electrolyte, hydrosol and coagulum." The increase in 

 colloidality observed in their studies they attribute, in the main, 

 to the formation of " acid palmitate." 



GOLDSCHMIDT and WEISSMANN hold that a satisfactory expla- 

 nation of the changes in the viscosity of their soap under the influ- 

 ence of alkalies and salts is still a matter of the future. They 

 emphasize as factors of possible worth changes in the hydrolytic 

 cleavage of the soap and the formation of acid soap, though how 

 such factors act they do not say. 



CLOWES' hypothesis reads as follows: 



"A dispersion of Na oleate in water represents a dispersion of particles 

 of oleic acid by means of NaOH. Further additions of NaOH lead to a 

 more perfect dispersion of the soap particles, owing to the fact that the 

 OH ion is more readily adsorbed than the Na ion. NaCl exerts a similar 

 effect to NaOH, the Cl ions exerting a dispersing effect analogous to that 

 of the OH ions, but since they are far less readily adsorbed than the 

 OH ions their effect is considerably smaller. . . . The soap particles 

 possess a negative charge attributable presumably to adsorbed anions. 

 This charge prevents their coalescence until the concentration of the 

 Na ions reaches such a point that they also come into play and by adsorp- 

 tion on the particles tend to counteract or diminish the negative charge 

 conveyed by the previously adsorbed OH or Cl ions. When a certain 



1 J. W. McBAiN and MILLICENT TAYLOR: Ber. d. deut. chem. Gesell., 43, 

 321 (1910). 



2 J. W. McBAiN and MILLICENT TAYLOR: Zeitschr. f. physik. Chem., 76 

 179 (1911). 



