Haematoxylon campechianum. Logwood.
Nat. Ord. — Fabaceae. Sex. Syst. — Decandria Monogynia.
Description. — This is a tree of from twenty to twenty-five feet in hight, and occasionally reaching forty or fifty feet. The trunk or stem is generally crooked and deformed, seldom exceeding a foot and a half in diameter and covered with a rough, ash-colored bark. The brunches are somewhat flexuose, terete, covered with whitish spots ; in mountains and moist situations they are unarmed, but in localities where the tree is stunted in growth, they are furnished with sharp spines below the leaves. The leaves are alternate, abruptly pinnate, and are composed of three or four pairs of subsessile, obovate or obcordate, obliquely-nerved leaflets. The flowers are yellow, slightly fragrant, on pedicels half an inch in length, and collected in axillary and subterminal racemes. The calyx is deeply five-parted, brownish-purple, with thin, membranous, deciduous, unequal lobes, and a short, green, campanulate tube. The petals are nearly equal, obovate, wedge-shaped at base, scarcely longer than the sepals, and of a lemon-yellowish color. The stamens are ten, alternately short, inserted on the inside of the margin of the persistent tube of the calyx ; filaments hairy at base ; anthers ovate, and without glands. The ovary is lanceolate, compressed, three-seeded, bearing a capillary style which projects beyond the stamens and petals ; stigma capitate, expanded. The pod or legume is flat, compressed, lanceolate, acuminate at both ends, one-celled, two-seeded, not opening at the sutures, but bursting in the middle longitudinally. The seeds are transversely oblong.
History. — This tree is a native of Campeachy and other parts of tropical America, and has become naturalized in many of the West India islands. The wood consists of a yellowish alburnum, and a dingy cherry-red inner wood, which last is the part used in medicine and the arts ; it forms a valuable article of commerce, and is extensively used in dyeing. It is imported in heavy, hard, close-grained billets, which are cut into chips, or rasped into a coarse powder for general use. It becomes darker-colored by exposure, has a sweetish, somewhat astringent, and peculiar taste, and a slight, rather pleasant odor. Water or alcohol extracts its coloring matter, forming deep-purple solutions. Its aqueous solution yields a fine blue precipitate with lime-water, alum, acetate of lead, a deep violet blue with the salts of sesquioxide of iron, and curdy flakes with solution of gelatin; sulphuric, nitric, muriatic and acetic acids, and sulphate of copper also produce precipitates. Water is the menstruum usually employed to extract its virtues. A pound of the wood yields about two ounces of extract. It has been analyzed several times, and is found to contain volatile oil, an oleaginous or resinous matter, a brown substance the solution of which is precipitated by gelatin, another brown substance soluble in alcohol, but not in ether or water, an azotized substance resembling gluten, free acetic acid, various salts, and a peculiar principle called Hematin or Hematoxylin, which is sometimes found crystallized in the crevices of the wood. It may be obtained by digesting the dry commercial watery extract with alcohol, evaporating the tincture till a thick, syrupy fluid is obtained, then adding a little water, and submitting the liquid again to a gentle evaporation. Crystals form in a few days upon standing, and more are deposited as the fluid evaporates spontaneously. These may be purified by washing with alcohol and drying. When first obtained they are of a yellow-rose color, shining, bitterish, acrid, and slightly astringent, readily soluble in boiling water, forming an orange-red solution which becomes yellow on cooling, and soluble also in alcohol or ether. If ether be used in the process instead of alcohol, and the purifying be accomplished by washing the crystals with water, they are obtained of a pale-straw color, becoming reddish-yellow by exposure to air containing the least trace of ammonia, or even in close vessels, to bright sunlight. They are sweet like liquorice, without either bitterness or astringency ; and though not a coloring substance of themselves, yet they afford beautiful red, blue, and purple colors when acted upon by an alkaline base and the oxygen of the air. Their constitution is C20 H17 O15.
Properties and Uses. — Logwood is tonic and astringent, without any irritating properties. It may be used with much advantage in diarrhea, dysentery, and the relaxed condition of the bowels succeeding cholera infantum. A favorite preparation with many practitioners in cholera infantum, after a proper employment of the Syrup of Rhubarb and Potassa, is the following: Dissolve two drachms of extract of logwood in four fluidounces of boiling water, to this solution add two fluidrachms of ammoniated tincture of opium, three fluidrachms of tincture of catechu, one fluidrachm of compound spirits of lavender, and four fluidounces of simple syrup, or syrup of ginger. The dose is a teaspoonful every three or four hours. In constitutions broken down by disease, dissipation, or the excessive use of mercury, the decoction of logwood, used freely in connection with the other treatment, will be found highly beneficial. Dose of the decoction from two to four fluidounces ; of the extract, five to thirty grains. The use of logwood imparts a blood-red color to the stools and the urine. It should never be combined with chalk or lime-water, as they are incompatibles.
A good red ink may be made as follows : Take of Pernambuco wood, a Brazilian wood said to be derived from Caesalpina Echinata, four ounces, dilute acetic acid, distilled water, of each sixteen ounces; boil together, until twenty-four ounces remain. Then add an ounce of alum, evaporate the liquid to sixteen ounces, dissolve an ounce of gum arabic in it, strain, and to the cold liquid add a drachm of protochloride of tin. This ink is preferable to the cochineal ink, being free from its bluish tint, and more permanent.
Off. Prep. — Decoctum Haematoxyli ; Extractum Haematoxyli; Vinum Haematoxyli Compositum.