naphthol (naf'thol)

A substance, C10H7.- OH, known in two isomeric forms: (1) a-n., crystallizing in shining needles having a smell like that of phenol, slightly soluble in hot water; (2) P-n., or is on', forming colorle rhombic tables, or a white crystalline powder, having a faint odor of phenol and a burning acrid taste, soluble in alcohol and in ether, and in 1,000 parts of cold water. After ingestion of n. it is excreted in the urine in combination with glycuronic acid. It is used as a test for sugar in Molisch's sugar test. B-n. is employed internally as an anti fermentative and externally in various cutaneous diseases, n'antipyrin. See naphtho pyrin. [Lat., naphtolum, naphtholum.1