There are two products of Guaiacum officinale, a large tree growing in the West indies, which are employed in medicine; namely, the wood, and a resinous substance obtained in various methods from the trunk. it is to the latter that the name of guaiac, as officinally used in this country, properly belongs.

1. Guaiacum Wood (Guaiaci Lignum), often called lignum vitae, is usually imported in billets, with the bark attached. it is hard, compact, and heavy, with the central or heart-wood of a brownish-green colour, and the outer portion or sap-wood, yellow. in the shops it is usually kept in the state of shavings or raspings, which have the two colours mixed. inodorous under ordinary circumstances, it acquires a distinct and somewhat fragrant smell when rubbed or heated. its taste is slight at first, but becomes feebly acrid when it is chewed. It yields its virtues partially to water, and completely to alcohol. These depend on an extractive matter and renin, the former of which is somewhat acrid, and is the only active part which water extracts from the wood.

2. Guaiac {Guaiaci Resina), or guaiacum resin, is obtained in three different methods. 1. it sometimes exudes in the form of a liquid juice from the tree, either spontaneously or through wounds in the bark, and concretes on exposure. 2. Another method of obtaining it is to bore a hole, by means of an auger, longitudinally into one end of a log or billet of the wood, and to put the other end into a fire. The resinous matter contained in it melts with the heat, and, running out through the auger hole, is received in vessels, in which it hardens. 3. The third, and, I presume, the most common method, is to boil the chips, sawdust, and pieces of bark, in water, holding common salt in solution, and to skim off the melted resin as it rises to the surface. Procured in this manner, it is in irregular masses, which are obviously full of impurities, such as small fragments of bark, etc., from which it may be freed by melting and straining.

Sensible and Chemical Properties. As guaiac is kept in the shops, it is usually in irregular lumps, of a greenish-brown or dark-olive colour on the outside, and, when broken, exhibiting a smooth, shining, con-choidal surface, which is at first reddish-brown, but assumes a green tint on exposure. The edges of the broken pieces are translucent. The powder is of a light-gray colour, changing to green with time, and is apt to cohere into a mass, which ultimately becomes compact and hard, in consequence, probably, of a partial fusion in hot weather. The odour is feeble, but agreeable, and increased by heat. The taste is at first scarcely perceptible, but after a time becomes sensibly acrid, and persists long. Guaiac softens in the mouth, melts at a low temperature, and is inflammable. it yields about nine per cent. of its weight to water, and is wholly dissolved, with the exception of impurities, by alcohol. it is also soluble in ether and alkaline solutions. The alcoholic solution is of a dark-brown colour, deposits resin on the addition of water, and imparts a blue colour to milk, gluten and vegetable products containing it, mucilage of gum arabic, etc. The change to green which guaiac undergoes on exposure, is thought to be owing to the absorption of oxygen. it consists of 9 parts of extractive matter, and 91 of resin, in 100 parts. The resin has peculiarities which distinguish it from other resinous substances, and has received the name of guaiacin. it has the acid property of uniting with alkalies to form soluble compounds, and, in view of this property, is sometimes called guaiacic acid. The mineral acids are incompatible with guaiac.

Effects of the Wood and Resin on the System. As the wood owes all its virtues to the guaiac contained in it, the effects of the two are identical, only that the wood is feebler. The ordinary remedial doses produce little observable effect. When the quantity taken is sufficiently large to make itself decidedly felt, there is a sense of warmth in the stomach, followed by slight anorexia, with dryness of the mouth, thirst, and often a moderate general excitement, indicated by some increase in the frequency of pulse and heat of skin. There is also a tendency to increased secretion, especially from the skin or kidneys; one or the other direction being taken, according to attendant circumstances. if the patient is kept warm in bed, and the powder of ipecacuanha and opium, or the antimonials, with warm drinks, are at the same time exhibited, profuse perspiration is often induced, probably more copious than it would be without the guaiac. if, on the contrary, the patient is walking about, and takes cold drinks, the medicine is more apt to act as a diuretic. in large doses it frequently operates on the bowels. it is thought also by some to stimulate the menstrual flux, and occasionally seems to act as a siala-gogue. Like other substances acting as irritants to the stomach and bowels, it sometimes occasions an eruption upon the skin. in great excess, it produces nausea, vomiting, purging, and febrile symptoms.

From its occasional effects in increasing perspiration, it has usually been ranked among the stimulating diaphoretics; but this effect is neither so considerable nor certain as to serve as a sufficient basis for classification.

Like sarsaparilla and some other acrid substances, guaiac appears to operate as an alterative, and, through this agency, to produce whatever curative effects are obtained from its use. it probably enters the circulation, and there excites the different emunctories, and at the same time the whole ultimate organic structure, including the capillaries; modifying its condition favourably in some cases of disease.

Therapeutic Application

The virtues of the wood are said to have been known to the aborigines, from whom the Spaniards derived the medicine. it was taken to Europe so early as 1508, and acquired great reputation in the treatment of syphilis, which gave origin to the name of wood of life {lignum vitae), by which it has ever since been distinguished. But its powers were greatly exaggerated; and at present it is considered as a mere accessary to other measures, and of very doubtful efficiency even in this capacity. it is almost never used, except in association with sarsaparilla, in the compound decoction and compound syrup of that root. The Edinburgh College still gave directions, in the last edition of their Pharmacopoeia, for a Decoction (Decoctum Guaiaci, Ed.), prepared by boiling guaiac wood, raisins, sassafras root, and liquorice root in water. it was the old decoction of the woods formerly in much repute as an adjuvant to an alterative course of mercurials or antimonials, in syphilis, chronic rheumatism, cutaneous affections, etc., but now very seldom used.

The resin is more active, and has considerable reputation in the treatment of rheumatism and some other diseases.

In acute rheumatism, it appears to be sometimes useful at that period of the disease when the time for depletion is passed, and moderate stimulation is not inadmissible. Under these circumstances, it may be given combined with opium and ipecacuanha, nitre, calomel, or the antimonials, one or more, in the dose of ten or fifteen grains every two hours. it is, however, probably better adapted to the subacute or neuralgic cases, and especially the chronic, in which it is much employed, either in the form of powder, or of tincture, which is generally preferred.

In the early stage of the hay asthma, during the existence of coryza, Dr. D. Lewis, of London, finds it useful, given every night at bedtime, in the dose of twenty grains, in a cup of warm tea.

It is also used occasionally in cases of chronic and irregular or nervous gout, especially when a stimulant is required.

In amenorrhoea and dysmenorrhoea, it was a favourite remedy with the late Professor Dewees, of Philadelphia; and, as the latter of these affections is probably often nothing more than disguised rheumatism, its usefulness is readily intelligible. I have myself employed it in some cases with apparent success; that is, the patients recovered under its use. in one instance, the woman, who was married and had previously been sterile, became pregnant.

Secondary syphilis, chronic cutaneous diseases, different forms of scrofula, and indefinite cachectic states of system without special name, have been treated with guaiacum; but always in combination with other remedies. Thus, it is one of the ingredients in the Compound Pills of Antimony (Pilulae Antimonii Compositae, U. S.; Compound Calomel pills, Pilula Calomelanos Composita, U. S. 1850, Br.), or Plummets pills, as they are commonly called, in which it is associated with calomel and precipitated sulphuret of antimony, and which are occasionally prescribed in the complaints above mentioned. (See page 306.)

Dr. James Jackson, of Boston, thinks that guaiac may sometimes be advantageously used as a laxative, in the dose of a drachm, in habitual constipation (Letters to a Young Physician, p. 291); and Dr. Brinton, of London, has found it highly useful in tonsillitis, given in the dose of from twenty to sixty grains, every four hours, with or without other medicines. (Lancet, Am. ed., July, 1857, p. 90 ) Dr. J. W. Walker, of Spilsby, England, while confirming the statement as to the efficacy of guaiac in all kinds of sore-throat, in which he regards it as a specific, recommends it as superior to all other remedies in diphtheria, in which, however, he gives it conjointly with chlorate of potassa and cinchona. The following is his formula;-mix together four scruples of chlorate of potassa, half a fluidounce of compound tincture of cinchona, from four to six fluidrachms of compound tincture of guaiac; a sufficiency of honey, and eight fluidounces of water. Of this mixture he gives from a fluidrachm to a fluidounce, according to the age, at intervals of from one to four hours. (Am. Journ. of Med. Sci., April, 1862, p. 522; from Med. T. and Gaz., Dec. 14, 1861.)


Guaiac is given in substance, or tincture. The dose of the resin is from ten to thirty grains, which may be exhibited in pill, or in powder suspended in milk, or in water rendered viscid by sugar and gum arabic. With water alone it will not mix. it may be made into the form of Mixture (Mistura Guaiaci, Br.), by rubbing together a drachm and a half of the powder, two drachms of sugar, and a drachm of powdered gum arabic, and adding, during the trituration, ten fluidounces of a mixture of equal parts of pure water and the U. S. cinnamon water. The dose of this mixture would be one or two fluidounces.

There are two tinctures, the simple and ammoniated.

The Simple Tincture (Tinctura Guaiaci, U. S.) is merely a solution of guaiac in alcohol, and is given in the dose of a fluidrachm three times a day, increased if necessary.

The Ammoniated Tincture (Tinctura Guaiaci Ammoniata, U. S., Br.) is prepared with aromatic spirit of ammonia, instead of alcohol, and differs from the preceding in being more stimulant, and at the same time somewhat antacid. The dose is the same.

Both tinctures are decomposed by water; and the resin thrown down refuses to mix with that fluid, so that it is advisable to administer the tincture in sweetened water, thin mucilage, or milk.