“ It behaves as a reducing agent. Chromic acid and potassium permanganate oxidize it to formic and carbonic acids, whilst hydrogen peroxide in the presence of ferrous salts gives dihydroxymaleic acid (H. J. H. Fenton, Jour. Chem. Soc, 1894, p. 899; 1895, pp. 48, 774; 1896, p. 546) . Hydriodic acid and phosphorus reduce it to malic acid and finally to succinic acid. Calcium chloride gives a white precipitate of calcium tartrate in neutral solutions, the precipitate being soluble in cold solutions of caustic potash but re-precipitated on boiling. ”

“ Dextro-tartaric acid occurs in the free state or as the potassium or calcium salt in grape juice and in various unripe fruits. During the alcoholic fermentation of grape juice it is deposited in the form of an impure acid potassium tartrate which is known as arg&l, and when purified as cream of tartar. For the preparation of the acid the crude argol is boiled with hydrochloric acid and afterwards precipitated as calcium tartrate by boiling with milk of lime, the calcium salt being afterwards decomposed by sulphuric acid. ”