THE COLLOID-CHEMISTRY OP SOAPS 



(1) 30 oc. 



(2) 1 oc, 



(3) 2.5 cc. 



(4) 5 oc. 



(5) 10 



(6) 15 



(7) 20 



(8) 25 



(9) 30 

 (10) 30 



TABLE X.\\ 



SODIUM CAPRYLATE SODIUM STBARATE MIXTURES 



oc. HiO (control) 



sodium caprylate +70 



+ 29 cc. 

 + 27.5cc. 



+ 25 cc. 



+ 20 cc. 



+ 15 cc. 



+ 10 oc. 



+ 5 oc. 



cc. 

 cc. 



cc 



cc 4 m 



cc. 4 m " " +70 cc. m 10 sodium stearate 



oc. HiO + 70 cc. m/10 sodium utearate 



+70 cc. m/ 10 sodium 



+70 cc. 



+ 70 cc. 



+ 70cc. 



+70 oc. 



+ 70 oc. 



+ 70 cc. 



IX 



ON REVERSIBILITY IN SOAPS 



1 



We noted early in our experiments that the physical con- 

 stants of the alkaline earth and heavy metal soaps, as ordinarily 

 prepared by precipitation of a sodium or potassium soap with 

 the salt of a heavier metal, were different from those of these 

 same soaps when prepared directly from a proper fatty acid and 

 a metallic hydroxid or oxid. We attributed the differences to 

 admixture of the heavy metal soap with the original soap. As 

 a matter of fact, we always deal in soaps thus prepared with a 

 mixture, in equilibrium, of the two soaps. In order to study the 

 matter further we performed the following experiments on the 

 reversion of soaps of the alkaline earths and the heavy metals 



the soaps of the alkali metals under the influence of alkali 

 hydroxids. 



The results in the case of a series of oleates may be thus illus- 



<-d. Molar equivalents of the hydrated oleates pictured in 

 Fig. 2 and described in Tal>l< 1 1 1 wore placed in separate vials. ' 

 The actual amounts were as follows: 



Magnesium oleat* 

 Calcium cleat, 

 Leadoleatc 



M.-r. ur\ olMftl 



Barium oleate 



These soaps were covered with 10 cc. normal KOH (the amount 

 necessary to convert, if possible, all the heavy soap into potassium 

 soap). The appearance of the soaps immediately after addition 



5.1 

 38 

 4.2 



I J i:r:uu- 



3. 



