220 PROFESSOR A. CRUM BROWN AND DR JAMES WALKER ON THE 



Suberic Acid from Castor-Oil. 

 Moo = 351 • 



V 



M 



100m 



K 



64 



14-79 



4-21 



00290 



128 



20-93 



5-96 



00296 



256 



29-08 



8-28 



00292 



512 



4060 



11-57 



00295 



1024 



55-78 



15-89 



•00293 



k = 00293 



The agreement between this number and that given by the synthetic acid serves to com- 

 plete the proof that the two substances are identical. 



The yield on electrolysis is about 28 per cent, of that demanded by theory. 



Synthesis of Sebacic Acid. 



The ethyl-potassium salt of adipic acid was made from synthetically prepared diethyl 

 adipate under the same conditions as were adopted in preparing the corresponding salt of 

 glutaric acid. 



The product of electrolysis is a colourless oil, which, when heated for some time to 



120°, loses small quantities of volatile bye-products, but retains a not unpleasant fatty 



smell while hot. When cold it is almost odourless. The oil distils undecomposed at 



305° ; the boiling-point of diethyl sebate is 307°. An elementary analysis gave the 



formula C 14 H 26 4 , — that of sebacic ether. 



■1452 gr. substance gave -3470 gr. C0 2 and -1329 gr. H 2 . 



Found. Calculated for C 14 H 2fi 4 . 



C . . . 65'18 per cent. 65-12 per cent. 



H . . . 1016 „ 1008 



A portion of the ether was saponified with potash, and the acid precipitated from 



solution of the potassium salt. It crystallised from water and alcohol in soft lustrous 



plates and melted at 128° ; the melting-point of sebacic acid is given as 127°. A potassium 



estimation resulted as follows : — 



•3662 gr. potassium salt gave '1808 gr. K 2 C0 3 . 



Found. Calculated for K 2 C 10 H 16 O 4 . 



K . . . 27-88 per cent. 2806 per cent. 



The dissociation constant of the acid was also determined. 



Synthetic Sebacic Acid, COOH-(CH 2 ) 8 -COOH . 



Moo =350. 



v fj, 100??^ k 



256 2801 800 -00272 



512 3932. 11-23 -00277 



1024 5428 1554 00278 



k = 00276 



