HÆMATOXYLUM, LOGWOOD, or CAMPEACHY WOOD; a genus of the monogynia order, belonging to the decandria class of plants.
Species. Of this genus there is only one species, viz. the campechianum, which grows naturally in the bay of Campeachy at Honduras, and other parts of the Spanish West-Indies*, where it rises from 16 to 24 feet high. The stems are generally crooked, and very deformed; and seldom thicker than a man's thigh. The branches which come out on each side are crooked, irregular, and armed with strong thorns, garnished with winged leaves, composed of three pair of obscure lobes indented at the top. The flowers come in a racemus from the wings of the leaves standing erect, and are of a pale yellowish colour, with a purple empalement. They are succeeded by flat oblong pods, each containing two or three kidney-seeds. * See Cam-
peachy.
Culture. The seeds, which are frequently brought from America, will readily grow if sown upon a good hot-bed in this country, and will thrive very well if kept constantly in a good degree of heat in the back-stove.
Uses. The logwood is used in great quantities for dyeing purple, but especially black colours. All the colours, however, which can be prepared from it, are of a fading nature, and cannot by any art be made equally durable with those prepared from some other materials. Of all the colours prepared from logwood, the black is the most durable. Dr Lewis recommends it as an ingredient in making ink. "In dyeing cloth, (says he,) vitriol and galls, in whatever proportions they are used, produce only browns of different shades: I have often been surprised that with these capital materials of the black dye I never could obtain any true blackness in white cloth, and attributed the failure to some unheeded mismanagement in the process, till I found it to be a known fact among the dyers. Logwood is the material which adds blackness to the vitriol and gall-brown; and this black dye, though not of the most durable kind, is the most common. On blue cloth a good black may be dyed by vitriol and galls alone; but even here, an addition of Logwood contributes not a little to improve the colour."—Mr Delaval, however, in his Essay on Colours, informs us, that with an infusion of galls and iron-silings, he not only made an exceeding black and durable ink, but also dyed linen cloth of a very deep black. See COLOUR-MAKING, n° 12, 13, 14.; DYEING, n° 17.; and INK. Logwood is also found to have a considerable astringent virtue as a medicine, and an extract of it is sometimes given with great success in diarrhoeas.