256 Proceedings of Royal Society of Edinburgh. [sess. 
temperature for 10 days the solution was still alkaline. The 
quantity of sodium added varied somewhat, but did not exceed one- 
fifth of an atom of sodium to one molecule of acetylendicarhoxylic 
ester. 
On pouring into water an oil separated, which was shaken out 
with ether, the ethereal solution dried over ignited sodium sulphate 
and the ether distilled off. On fractionating under reduced 
pressure the whole of the product came over within two or three 
degrees, and the boiling point was fully 25° higher than that of 
the acetylendicarhoxylic ester, namely, 145-146° at 17 mm. 
pressure. 
Analysis gave the following results : — 
0*180 lg substance yielded 0*1352gH 2 O and 0*36gCO 2 . 
Calculated for Diethoxysuccinic Ester. 
C . . . 54*52% 54*96% 
H . . . 8*34% 8*34% 
The same diethoxysuccinic ether was obtained by the action of 
sodium ethylate in alcoholic solution in the cold on dibromsuccinic 
ether, prepared from fumaric acid by the action of bromine and 
subsequent esterification. Rather more than the calculated quan- 
tity of sodium was added, and the solution was kept alkaline for 
a fortnight. The oil thus got boiled at 144-145° at 16 mm. 
pressure. 
On hydrolysis with alcoholic potash a white pearly potassium 
salt was formed, insoluble in alcohol, hut easily soluble in water. 
From the aqueous solution the insoluble lead and calcium salts 
were prepared by double decomposition. Analysis of these salts 
gave numbers agreeing fairly well with the theoretical numbers 
for salts of diethoxysuccinic acid. 
The diethoxysuccinic ether prepared in these ways is the unsym- 
metrical body, the acetal derivative of oxal-acetic ether. Michael 
and Bucher have already shown that this is the case (Ber. 1895, 
2511). 
If diethoxysuccinic ether is allowed to stand with concentrated 
hydrochloric acid for 24 hours and the solution then made alkaline 
with caustic potash and boiled — on neutralising with acetic acid 
and adding calcium chloride a precipitate of calcium oxalate is 
