Found. 



Calculated for C 10 H 18 O 4 . 



5 9 '26 per cent. 



59 - 41 per cent. 



911 „ 



891 „ 



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



The ethyl-potassium salts prepared by this method are all amorphous, and, apart from 

 the presence of potassium carbonate, highly deliquescent substances, soluble to some 

 extent in alcohol, and insoluble in ether. 



Ethyl-potassium succinate yields on electrolysis a light straw-coloured liquid, which, 

 after warming for a short time at 100°, loses its at first somewhat unpleasant smell, but 

 retains a feeble odour resembling that of melons. The liquid boils with slight decomposi- 

 tion at 240° ; according to Arppe, the boiling-point of adipic ether is 245°. An analysis 

 resulted as follows : — 



•1735 gr. substance gave '3770 gr. C0 2 and 1423 gr. H 2 0. 



C 

 H 



The formula is that of diethyl adipate. A portion of the ether was saponified by alcoholic 

 potash, and from the solution of the potassium salt we prepared the silver salt and the 

 acid by precipitation. The acid melted at 147°, the melting-point of adipic acid being 

 148°. An ignition of the silver salt gave the following numbers : — 



•2388 gr. substance yielded - 1428 gr. Ag . 



Found. Calculated for Ag 2 C a H 8 4 . 



Ag . . . 5 9 "8 per cent. 60 - per cent. 



The yield of diethyl succinate is 35 per cent, of the theoretical quantity. 



An experiment conducted precisely as above, only that dimethyl succinate was used as 

 starting-point instead of the diethyl ether, gave as chief product of electrolysis an aromatic 

 oil, which on purification and analysis proved to be dimethyl adipate. 



■1160 gr. substance gave -2360 gr. C0 2 and "0863 gr. H 2 . 



Found. Calculated for C 8 H 14 4 . 



C . . . 5 5 "48 per cent. 55*17 per cent. 



H . . . 827 „ 8-05 



The dimethyl ether begins to decompose at 210°. The yield is somewhat smaller than 

 in the case of the ethyl compound. 



A determination of the dissociation constant of the acid was made with the following 

 result : — 



Synthetic Adipic Acid, COOH(CH 2 ) 4 COOH 

 Moo =352. 



s 



V 



M 



100m 



K 



32 



11-85 



3-37 



00366 



64 



1660 



4-72 



00364 



128 



2334 



663 



•00368 



256 



32-27 



9-17 



00362 



512 



4501 



12-79 



•00366 



1024 



61-65 



1751 



00363 





K = 



•00365 





