Phenol phthalein

Phenol Phe"nol, n. [Gr. ? to show + -ol: cf. F. ph['e]nol.] (Chem.) 1. A white or pinkish crystalline substance, {C6H5OH}, produced by the destructive distillation of many organic bodies, as wood, coal, etc., and obtained from the heavy oil from coal tar. [1913 Webster]

Note: It has a peculiar odor, somewhat resembling creosote, which is a complex mixture of phenol derivatives. It is of the type of alcohols, and is called also {phenyl alcohol}, but has acid properties, and hence is popularly called {carbolic acid}, and was formerly called {phenic acid}. It is a powerful caustic poison, and in dilute solution has been used as an antiseptic. [1913 Webster]

2. Any one of the series of hydroxyl derivatives of which phenol proper is the type. [1913 Webster]

{Glacial phenol} (Chem.), pure crystallized phenol or carbolic acid.

{Phenol acid} (Chem.), any one of a series of compounds which are at once derivatives of both phenol and some member of the fatty acid series; thus, salicylic acid is a phenol acid.

{Phenol alcohol} (Chem.), any one of series of derivatives of phenol and carbinol which have the properties of both combined; thus, saligenin is a phenol alcohol.

{Phenol aldehyde} (Chem.), any one of a series of compounds having both phenol and aldehyde properties.

{Phenol phthalein}. See under {Phthalein}. [1913 Webster]