In our previous communications to the Society (see Trans. xxxvi. 211) we described the behaviour of the ethyl potassium salts of normal dibasic acids on electrolysis. These we found always to yield the diethyl esters of normal acids of the same series. We have now extended our investigation to acids with side chains, and in this paper give an account of the electrolysis of ethylpotassium methylmalonate and ethylpotassium ethylmalonate.