hydroxy-

This compound combines with hydrocyanic acid to form a nitrile which hydrolyses to dichlor-hydroxy iso-butyric acid.

The soluble red, blue, and violet pigments are glucosides of various hydroxy-derivatives of the anthocyan nucleus.

Another of these substances is ellagic acid C14H6O8, a double lactone of a hexa-hydroxy-diphenyldicarboxylic acid.

But along with these three general classes are found all kinds of connecting links: Acid salts, basic salts, hydroxy acids, etc.

The next group may be called hydroxy-azo dyes, and are quite of modern introduction.