( 857 ) 



poured on to pounded ice in order to pre\ent as much as possible 

 a rise in temperature and consequent saponilication. Sufficient alcohol 

 is now added so as to obtain a öO''/^ alcohol mixtui-e and this is 

 then shaken with a mixture of ether and petroleum ether. After 

 washino- with water tlie ether is evaporated. In experiment c a sub- 

 stance was left with ester number and acid number 280.5, which 

 points to pure hxuric acid. This proves that all the trilaurin was 

 decomposed. 



On repeating' experiment c with subsequent heating at 60° for 

 1\/, hour and removing the sulphuric acid in rhe manner described 

 a substance was obtained with acid number 246.8 and saponification 

 number 280.9; ester number 34.1. As trilaurin [assesses an ester 

 number 263.8, 12.9 7o of trilaurin has been regenerated. 



As regards the lauric acid which in the previous equation occurs 

 together with glyceroltrisulphuric acid it must be remarked that this 

 unites with H^SO^ to molecular compounds which are more or less 

 soluble in benzene. Now if trilaurin is dissolved in 100 "/„ acid 

 (experiment c) and if this is shaken with dry benzene both lauric 

 acid and sulphuric acid may be detected in that solvent. Compounds 

 of a similar character have been described by Hoogewerff and van 

 Dorp ^). In these additive compounds the oxygen is sometimes taken 

 as quadrivalent such as : 



H 



= — — SO,H 

 RCOOH -I- H,SO, = R — C — — H 



Others, H. Meijer '), believe in the existence of a kind of mixed 

 acid anhydrides : 



= 

 R . COOH + H,S0, = R — C — — SO,H + H,0. 



The latter is improbable as then we should want in all tliese 

 compounds exactly J mol. of water of crystallisation for 1 mol. of 

 the two acids. We already noticed in the saponification of butter fnt 

 that the concentration of the acid plays an important part; this is 

 also the case with trilaurin. If now at a temperature of 1 — 2'" we 

 allow 52 raols. of 94.67„, sidphuric acid to act on 1 mol. of tri- 

 laurin for 30 minutes a substance was obtained, aftei- i-emoval of 

 the sulphuric acid, consisting of 807» of lauric acid and 207o of 

 undecomposed glyceride. This glyceride was separated from the 



ij Recueil XVIII 1899 bl. 211. 



-) Monatshefte fqr Chemie 24 p. 840. 



