Meldruml observed that malonic acid and acetone react in the cold in acetic anhydridesulfuric acid medium, eliminating the elements of water to form a crystalline product, C6Hs04. Since this proved to be a monobasic acid which could be titrated in aqueous solution, Meldnun concluded that one of the carboxyl groups of the malonic acid molecule remained intact and proposed that the structure of the new compound was P,@- ...