Guaiacum Wood. Synonym. - Lignum vitae. The heart-wool of Guaiacum officinale Linne, and of Guaiacum sanctum Linne (nat. ord. Zygophylleae).


West Indies, North and South America.


Heavier than water, hard, brown or greenish-brown, resin ous, marked with irregular, concentrated circles, surrounded by a yellowish alburnum, splitting irregularly; when heated, emitting a balsamic odor; taste slightly acrid. Guaiacum Wood is generally used in the form of raspings or turnings, which should be greenish-brown, containing few particles of a whitish color, and should acquire a dark bluish-green color on the addition of Nitric Acid.


The principal constituent is the Resin (see below), 20 to 25 per cent.

Guaiacum Wood is used to make Decoctum Sarsaparillae Compositum.

Dose, 1/4 to 1 dr.; 1. to 4. gm.

Guaiaci Resina. Guaiac. Gum Guaiac

Synonym. - Gum Guaiac. The resin of the wood of Guaiacum officinale Linne (nat. ord. Zygophylleae).


By melting the resin of the heartwood by fire.


In irregular masses, or subglobular pieces, externally greenish-brown, internally of a glassy lustre, and, in recent Guaiac, usually reddish-brown, transparent in thin splinters, fusible, feebly aromatic, the odor becoming stronger in heating; taste somewhat acrid; powder grayish, turning green on exposure to air. Guaiacum Resin on dry distillation yields Cresol and Guaiaco/, also found in Creosote (see p. 334). Resembling Guaiacum Resin. - Myrrh, Scammony, Benzoin, Aloes, and Resin, but these have no greenish tinge.


The chief constituents are three resins - (1) Guaiaconic Acid, C19H20O5 (70 per cent.). (2) Guaiacic Acid, resembling Benzoic Acid. (3) Guaiaretic Acid, C20H26O4 (about 10 per cent.). These are insoluble in water, soluble in alkalies, but precipitated on neutralization.

Incompatibles. - Mineral acids and spirit of nitrous ether.

Guaiac Resin is contained in Pilulae Antimonii Composite.

Dose, 5 to 30 gr.; .30 to 2.00 gm.


x. Tinctura Guaiaci. - Tincture of Guaiac. Guaiac, 200. By maceration with Alcohol, and filtration to 1000. Dose, 1/2 to 1 fl. dr.; 2. to 4. c.c.

2. Tinctura Guaiaci Ammoniata.- Ammoniated Tincture of Guaiac. Guaiac, 200; by maceration with Aromatic Spirit of Ammonia, and filtration to 1000.

Dose, 1/2 to 1 fl. dr.; 2. to 4. c.c.

Action Of Guaiac


The tincture of guaiac is used for the detection of blood stains.


Guaiacum resin gives rise to an acrid feeling in the throat and a sensation of heat in the epigastrium. It increases the secretions and movements of the intestine and stomach. Large doses are gastro-intestinal irritants, causing vomiting and purging. It reflexly stimulates the heart.

Therapeutics Of Guaiac


Guaiacum resin is so disagreeable and its value so doubtful that it is rarely ordered. It is used empirically, sometimes successfully, for chronic sore throat, especially if the subject has had syphilis. Lozenges (13 gr. .20 gm. of the resin with a fruit basis) are preferred. The mixture B. P., Guaiacum resin, 6; sugar, 6; tragacanth, 1; cinnamon water, 240; dose, 1/2 to 1 fl. oz., 15. to 30. c.c. is said to be a more efficacious preparation than that of the tincture. Thirty grains 2. gm. of the powder itself may be placed on the back of the throat and swallowed. Guaiacum is a mild purgative, and it has been given as a pill in chronic constipation; this property accounts for its presence in compound cathartic pills. Lately it has been strongly recommended by Garrod as a means of warding off attacks of gout. For this purpose 12 gr., .75 gm. of the powdered resin may be taken in a cachet for an indefinite period, even several years. It is well to follow it by a draught of effervescent lithium citrate. It was formerly employed in chronic rheumatism.