( 856 ) 



Moreover, the lii^li temperature al wliich the action of the acid 

 takes place is imsiiitaliie foi- tiie piirjxjse of a complete saponification, 

 because, as will he seen, it is just the increase in tem[)erat ure which 

 causes the shiftifig of the equilibrium in equation (2) towards the 

 left. On repeating Bünte's method T obtained the following figures : 

 With 93.5» „ acid the butter fat was resolved to 81.0° „ of free fatty acid 



,, yo.o /g ,, ,, ,, ,j ,, jj j^ oy. / /g ,, ,, ,, ,, 

 ,, iuu.u /„ ,, ,, ,, ,, ., ,, ,, y2.2 J ,, ,, ,, ,, 



From these figures, the influence of the concentration of the sul- 

 phuric acid is very obvious ; also the im[)erfection of the method so 

 that it cannot be a matter of surprise that it has been entirely- aban- 

 doned. 



In order to get a better insight into the action of concentrated 

 sulphuric acid on fats I chose as starting material pure trilaurin 

 prepared from Tiingkallak fat obtained from the fruits of Cjlicodaphne 

 Litsaea, a tree growing in West Java. The fat consists of trilaurin 

 and triolein so that it is easy to prepare trilaurin from the same by 

 recrystallisatioJi from ether. 



The sulphuric acid employed was 100.0 "/„ as determined by titra- 

 tion. Experiment a took place at a temperature of 18^, experiment 

 b and c at 1 — 2''. Time of action 30 minutes. 



a 1 mol. of trilaurin to 6.5 mol. of i/j, 6'0, gave 86. 67„ free fatty acid 

 ^ 1 w „ „ „ 26.0 „ „ H, ;SÜ, „ 95.5V„ „ „ „ 

 c 1 „ „ „ ,. 52.0 „ „ //, SO, „ 100.0« ; „ „ „ 

 the reaction : 



trilaurin -f- sulphuric acid = glyceroltrisulphuric acid -)- lauric acid 

 seems, therefore, only practically complete with a very large excess 

 of sulphuric acid and at a low temperature, for if experiment c is 

 repeated and then again heated at 60 for IV', hour, a shifting towards 

 the left takes place and trilaurin is regenerated. The course of the 

 investigation is briefly as follows : 



The 100.0"/„ sulphuric acid is weighed in a tlask which is then 

 corked and placed in ice water. The weighed trilaurin is now added 

 in small quantities. As by the action of the acid on trilaurin heat 

 is generated no fresh portion of trilaurin must be added until the 

 previous lot has dissolved '). When all the trilaurin has dissolved 

 and the time of action has exj)ired the contents of the flask are 



^) From this evolution of heat witli saturated compounds it follows that no 

 undue importance should be attached to Maumené's experiment (Compt. rend. 1882. 

 35 pg572) where lliis evolution of heat is made use of to detect unsaturated compounds. 



