HYDRACRYLIC ACID (ethylene lactic acid), CH 2 OH-CH 2 - CO 2 H, an organic oxyacid prepared by acting with silver oxide and water on |3-iodopropionic acid, or from ethylene by the addition of hypochlorous acid, the addition product being then treated with potassium cyanide and hydrolysed by an acid. It may also be prepared by oxidizing the trimethylene glycol obtained by the action of hydrobromic acid on allylbromide. It is a syrupy liquid, which on distillation is resolved into water and the unsaturated acrylic acid, CH 2 : CH-CO 2 H. Chromic and nitric acids oxidize it to oxalic acid and carbon dioxide. Hydracrylic aldehyde, CH 2 OH-CH 2 -CHO, was obtained in 1904 by J. U. Nef (Ann. 335, p. 219) as a colourless oil by heating acrolein with water. Dilute alkalis convert it into crotonaldehyde, CH 3 -CH : CH-CHO.