G. Williams 193 



of this process to the residues from the first esterification, whereas in 

 this hydrolysis nearly double that amount was obtained. 



Fractional distillation of tlie esters. 



The ethereal solution was poured ofi from the sodium sulphate 

 and the ether boiled ofi under reduced pressure. (It would have 

 been better to have driven oS the ether at ordinary pressm'e, because 

 condensation would have taken place and the distillate could have been 

 worked up for any esters which might have distilled over.) The esters 

 were then fractionally distilled in an apparatus similar to that described 

 by Fischer^. 



Three fractions only were obtained, further fractionation being 

 unnecessary. The lowest pressure was obtained by absorbing the 

 remaining gases in an evacuated tube containing freshly prepared 

 cocoa-nut fibre charcoal surrounded by liquid air. 



Table of fractions obtained. 



The liquid air condenser contained 24-1 grms. of liquid, mostly chloro- 

 form and ether. Fraction 1 also contained chloroform and ether. 

 The undistilled residue weighed 32 grms. 



Preparation of a second yield of esters. 



The baryta used for liberating the esters was now treated so as to 

 produce a second lot of esters. The undistilled residue and the substance 

 insoluble in ether (soluble in chloroform) were also treated for the same 

 purpose. 



(i) Treatment of the baryta and barium chloride mixture. 



The dry mixture was placed in a beaker and a litre of water added. 

 It was then warmed and treated with sulphuric acid (1 to 3) until no 

 further precipitate was obtained. The liquid was now strongly acid 

 owing to the hydrochloric acid liberated from the barium chloride. 

 The barium sulphate was filtered off and thoroughly washed in the 

 usual manner. The weight of the barium sulphate was 562 grms. and 

 it contained 2-24 grms. of nitrogen. 



1 Fischer and Harries, B&r. xxxv, 2158, 1902. 



