The resin of Guaiacum officinale or G. sanctum.

Preparation. - Obtained from the stem by natural exudation, by incisions, or by heat.

Characters. - In masses of a greenish-brown or reddish-brown colour; fractured surface resinous, translucent at the edges, where the greenish colour is usually well-marked, and serves to distinguish this from other resins. A solution in rectified spirit strikes a clear blue colour when applied to the inner surface of a paring of raw potato (p. 68), or on the addition of tincture of perchloride of iron. Powder greyish, turning green on exposure to air.

Composition. - It contains several resinous acids, guaiaconic, guaiaretic, and guaiacic acids; these are soluble in alkalis and are precipitated on neutralisation.

Dose. - 10 to 30 gr.

Preparations

B.P.

Dose.

Mistura Guaiaci.........................................................................

1-l 1/2 fl. oz.

Tinctura Guaiaci Ammoniata.................................................

1/2-1 fl. dr.

Pilula Hydrargyri Subchloridi Composita (v. p. 522)

5-10 gr.

U.S.P.

Tinctura Guaiaci..........................................................................

1-3 fl. dr. (4-12 c.c.)

,, ,, Ammoniata.......................................................

1-2 fl. dr. (4-8 c.c.)

Pilulae Antimonii Compositae (v. p. 523)..................................

1-2 pills.