Guaiacol is one of the chief constituents of beechwood creosote.

Properties : Guaiacol is a colorless or nearly colorless crystalline solid, melting at 28.5 C. (83.3 F.) or a refractive liquid, having an agreeable aromatic odor. It is soluble in water (1:53), and miscible with alcohol in all proportions.

Action and Uses: Guaiacol is antiseptic and germicidal, but to a less degree than creosote. When rubbed on the skin it is absorbed. When given in this way it is an active antipyretic, but its action is not easily controlled. It is an intestinal antiseptic and also an expectorant. It is not excreted by the lungs, however.

Dosage: Guaiacol may be given in emulsion or in the form of capsules. The initial dose should be 0.1 c.c. or about 1½ minims, gradually increased to 0.6 c.c. or 10 minims, if well borne. It is sometimes applied to the pharynx as a 50 per cent, solution in glycerin. The local use of guaiacol as an antipyretic is not to be recommended on account of the symptoms of collapse which sometimes follow these applications.