Synthesis of Tetramethylsuccinic Acid.–Ethyl-potassium dimethylmalonate cannot be prepared from dimethylmalonic ether by following precisely the method which succeeded in all previous cases. When the ether is mixed, either at once or slowly, with the calculated quantity of caustic potash in alcoholic solution, half of the ether is completely saponified, while the other half is unacted on, only an insignificant fraction being half-saponified and converted into the ethyl-potassium salt. A good yield of the latter was, however, obtained by a modification of the process, the special points of which were great dilution with alcohol and low temperature