1892 - 93 .] Prof. C. Brown and Dr J. Walker on Synthesis. 247 
The quantity of ethereal product boiling at a comparatively low 
temperature was much smaller in the case of the monoalkyl malonic 
acids than with the dialkyl acids. From methylmalonic acid, acrylic 
ether, and from ethylmalonic acid a crotonic ether might be ex- 
pected. Small quantities of ethers probably containing acrylic 
ether and a crotonic ether respectively were obtained, but not 
identified with certainty. In the case of the crotonic ether it seemed 
to be accompanied by the corresponding saturated ether (butyric 
ether), a circumstance not theoretically unlikely. 
Products from Sehacic Acid. — By careful working it was found 
possible to raise the yield of ?^-dicarbodecahexanic ether from 20 to 
about 40 per cent, of the theoretical. The solid product of the 
reaction was spread on porous plates, when about two-thirds were 
absorbed. AVhat remained was nearly pure ?z-dicarbodecahexanic 
ether. The porous plates were broken up and extracted with ether 
in a fat-extracting apparatus. The ethereal extract was dried and 
distilled at atmospheric pressure. The chief fractions were, one be- 
tween 240° and 270°, and one between 280° and 310°. The residue 
was mainly ?^-dicarbodecahexanic ether. The fraction 240°-270° 
consisted essentially of sebacic ether. 
The oily acid from the fraction 240°-270° was purified as far as 
possible, but as the quantity was small the acid was not obtained 
in a perfectly pure state. Analysis indicated the formula CgH^gOg. 
0'1881 gramme gave 0'4755 gramme COg and 0T785 gramme HgO-. 
Calculated for CgHigOg. Found. 
C . . . 69-23 68-94 
H . . . 10-26 10-54 
The acid united slowly with bromine at ordinary temperature. 
It was obviously an unsaturated acid and a normal product of the 
electrolysis. The barium was determined in its barium salt ; 
0-2106 gramme of the salt dried at 130° gave 0-1085 gramme 
BaSO,. 
Calculated for Ba(C 9 Hi 502 ) 2 . Found. 
Ba . . . 30-6 30-3 
Limits of Applicability of the method of Electrolytic Synthesis of 
Dibasic Acids. — Experiments made with ethyl-potassium fumarate, 
ethyl-potassium maleate, ethyl-potassium citraconate showed that the 
