357 



persitj of the emulsion to decrease.') A consequence of this is that 

 in the initial stage of (he second phase a considerable separation of 

 glycerine takes place. 



In the saponification in emulsion the relation between the relative 

 concentrations of free fatty acid and free glycerine is now deter- 

 mined bj the adsorption of the lower glycerides at the surface of 

 contact between fat and water. In this case the three estergronps of 

 the triglyceride may be taken as equivalent with very close approxi- 

 mation. The equation T =: '^/^ (g -\- g'ls -\- g^z), which is founded on 

 this supposition, and which holds for the TvviTCHELL-process, holds 

 also at the end of the second phase of the sulphuric acid saponification, 

 when the water contains but little sulphuric acid (from 1 to 27o)- If 

 the acid content in the water is greater, then 7^^ \/j, {g -{- g^'^ -\- g^l^). 



SUMMARY. 



The relation between the relative concentrations of free glycerine 

 and free fatty acid was derived for the ideal case that tri-glyceride 

 saponification takes place in solution, the ester groups are equiva- 

 lent, and no complications present themselves. 



It holds that the relative concentration of the free glycerine is at 

 any moment equal to the third power of the relative concentration 

 of the free fatty acid in case of stage wise saponification. 



The same thing holds for the ideal case of esterification. 



In the saponification of trilaurine with strong sulphuric acid only 

 a very slight deviation was found, caused by the not perfect equi- 

 valence of the three ester groups. This is a direct and quantitative- 

 proof of the stage wise course of the reaction. 



In the esterification of equivalent quantities of laurinic acid and 

 glycerine dissolved in strong sulphuric acid deviations were found, 

 which are probably caused by the action of the two-basic sulphuric acid. 



Gouda, May 1917. Laboratory of the Royal Stearine 



Candle Works "Gouda". 



1) In treating fats, containing unsaturated acids, with strong sulphuric acid at 

 high temperature, compounds are formed that keep up the dispersity of the emul- 

 sion during a longer time. 



