54 Proceedings of Royal Society of Edinburgh. [sess. 
The following paper shows that this expectation has been 
•fulfilled. 
Dr Walker and I are at present engaged in applying this method 
to other dibasic carbon acids, saturated and unsaturated, and hope 
shortly to communicate further results. 
The Electrolysis of Potassium-Ethyl Malonate and of 
Potassium- Ethyl Succinate. By Prof. Crum Brown 
and Dr James Walker. 
(Read February 17, 1890.) 
{Abstract.) 
Synthesis of Succinic Acid. — Potassium-ethyl malonate is easily 
prepared according to the directions of Freund ( Berichte dev deut. 
chem. Gesellschaft , xvii. 780). 
The conditions most favourable for the electrolysis were found 
to be as follows : — A large platinum crucible formed the cathode, 
while a spiral of stout platinum wire was used as the anode. The 
source of electricity was a battery of accumulators, and the current 
w T as so regulated that while passing through the solution it had an 
electromotive force of 12 volts and a strength of not more than 5 
amperes. Under these circumstances the heat developed in the 
solution could be easily conducted away by a stream of cold water 
flowing round the platinum crucible. Heating is to be avoided, on 
account of possible saponification of the potassium ethyl salt by the 
action of the caustic potash formed at the cathode. With the above 
arrangement, however, the hydrogen developed at the cathode 
serves to stir up the liquid and bring the potash into contact ‘with 
the carbonic acid liberated at the anode, and thereby convert it into 
carbonate, which, far from being prejudicial to the action, seems on 
the whole advantageous. One point to be attended to is that the 
solution should not be too concentrated. When this is the case the 
liquid has a high resistance, and the electrolysis proceeds slowly ; 
the product, too, is not so satisfactory as when the solution is so far 
diluted that a brisk evolution of gas takes place at both poles with- 
out any excessive frothing being occasioned by the viscosity of the 
