ELECTROLYTIC SYNTHESIS OF DIBASIC ACIDS. 373 



salt crystallised with one molecule of water for each atom of calcium. The acid prepared 

 from the barium salt was a clear colourless liquid with a penetrating odour. It solidified 

 in a freezing mixture, and fused again about 0°, but gave no sharp fusing-point. 

 Prolonged heating to 190° did not convert it into solid crotonic acid. Its specific 

 gravity at 13°'5, compared with water at 4°, was 1*010. Combustion of the ethyl ether 

 (boiling at 132°- 134°) gave numbers lying between those calculated for ethyl crotonate 

 and those for ethyl butyrate, viz., 62'54 per cent, carbon and 971 per cent, hydrogen. 

 The ether was probably a mixture of these two substances. 



We shall have occasion again to refer to the production of the compound ether of 

 the saturated monobasic acid. The ether and also the acid prepared from it slowly 

 decolorised bromine in carbon disulphide solution at ordinary temperature. 



PRODUCTS FROM SeBACIC AciD. 



By careful working it is possible to raise the yield of diethyl dicarbodecahexanate 

 prepared by electrolysis, which was stated in our former paper as 20 per cent., to about 

 40 per cent, of the theoretical amount. The solid product of the electrolysis was spread 

 on porous earthenware plates, which absorbed about two-thirds of it. The remaining 

 mass was nearly pure dicarbodecahexanic ether. The plates were then broken down and 

 extracted with ether in a fat-extracting apparatus. The ethereal extract was dried and 

 distilled at atmospheric pressure. The chief fractions were — one between 240° and 270° 

 (boiling-point about 250°), and one between 280° and 310° (boiling-point about 300°), 

 the two together forming about one-third of the liquid ethereal product. 



These fractions were separately saponified with caustic potash. The portion boiling 

 above 310° was distilled under diminished pressure, and was found to consist essentially 

 of dicarbodecahexanic ether, which solidified in the condenser. 



The acid from the fraction 240°-270° was a yellowish oil, which partly solidified on 

 standing for a considerable time. The semi-solid mass was separated by means of porous 

 plates into a white solid acid, and a yellowish viscid acid. The solid acid, after two 

 recrystallisations from water, in which it was sparingly soluble, gave a fusing-point of 

 127°. It was therefore apparently sebacic acid. The same acid was precipitated in white 

 flocks sparingly soluble in cold water, on acidifying the solution of the potassium salt 

 obtained by saponifying the fraction boiling between 280° and 310°. It gave the fusing- 

 point 127°-128°, and gave the following numbers on combustion : — 



01748 gramme substance gave 03809 gramme C0 2 and 0\L440 gramme H 2 0. 

 Calculated for C l0 H 18 O 4 . Found. 



C 59-41 5943 



H 891 916 



The acid was therefore sebacic acid. 



Acid Q,H 16 2 . — The oily acid from the fraction of the ether boiling between 240 



