1889 - 90 .] Prof. Crum Brown & Dr Walker on Electrolysis. 55 
liquid. After the current has passed for some time, a deposit begins 
to be formed in the solution. This is mainly potassium carbonate, 
with possibly some bicarbonate. When this has increased somewhat 
in quantity the current is broken, and the contents of the crucible 
transferred to a separating-funnel, where they are shaken up with 
ether. A further quantity of carbonate is thereby precipitated. 
The aqueous layer is then allowed to ritn out, nearly all the solid 
carbonate remaining behind, and the ethereal layer is poured off. 
The former is again submitted to electrolysis, and the extraction 
with ether repeated. The ethereal liquids are united, dried with 
calcium chloride, and the ether distilled off on a water-bath. 
In our first experiment, made with 15 grams of the double 
malonate, there remained in the distilling-flask over 3 grams of a 
nearly colourless liquid of ethereal odour. This liquid was sub- 
jected to fractionation; it passed over almost entirely at 213° 
(uncorr.) : the boiling-point of succinic ether is 216°. A portion 
of the distillate was analysed, with the following results : — 
•2619 gr. substance gave ’5287 gr. C0 2 
and T930 gr. H 2 0 
Found. Calculated for Succinic Ether. 
C 55-06% 55-17% 
H 8-19 8-05 
There was thus little doubt that the substance so obtained was 
succinic ether. In confirmation, however, a portion of the ether 
was saponified, and the white silver salt precipitated. This salt was 
then carefully ignited, and the residue of silver weighed. 
T878 gr. substance gave *1215 gr. silver. 
Found. Calculated. 
Ag. 64-7 65-0 
Synthesis of Adipic Acid . — Heintz ( Poggendorff’s Annalen , 108, 
82 [1859]) obtained potassium-ethyl succinate by treating succinic 
anhydride with absolute alcohol, neutralising with potassium car- 
bonate, and precipitating the double salt from its alcoholic solution 
with ether. 
The conditions to be observed in the electrolysis are quite the 
same as in the case of potassium ethyl malonate, and the mode of 
