129. Brazil wood, as an article used in dyeing, is the heart, or central part, of a large tree which grows in Bra zil. Bcrthollet states, that it derives its name from that part of South America ; but Dr Bancroft has decidedly proved, that the country took its name from the wood, not the wood from the country. Brazil wood is men tioned in some old charters, particularly one dated in 1198, and another it 130G, under the name of Braxilis, which, as tycll as Brasilis, is understood to be derived from bragio, a burnizg coal, to denote its fiery red, or flame colour. It ;s ai.,o called Fernambucca, wood of St Martha. of Japan, and of Sapan. Linnaeus describes the tree which furnishes Brazil wood under the name Cesalpina crista ; that which gives the Japan or Sapan wood, by the name Ciesalpina sappan; and that of An tilles, which is the least esteemed, he calls Ciesalpina vesicaria. That which comes from Fernambucca is the most valuable.
130. Brazil wood is very hard, and takes a good po lish. It is pale when first cut, but reddens by exposure to the air. It sinks in water, and its goodness is known by its weight. Boiling water extracts the whole of its colouring matter, and becomes of a fine red if the boil ing be continued sufficiently long. A black residuum remains, which still yields much colouring matter to al kalies. A more perfect solution is obtained by alcohol, and also by ammonia ; at least the colour is deeper. The practice of sprinkling the powder of Brazil wood, during the operation of grinding it, with stale urine, probably raises the colour, by means of the volatile al kali which it contains.
131. Fresh decoction of Brazil wood yields, by the addition of sulphuric acid, a small quantity of a red pre cipitate, inclining to fawn colour ; the liquor remains yellow and transparent. Nitric acid renders the liquor yellow at first ; but if more be added, the liquor ac quires a deep orange colour, and becomes transparent, after having deposited a precipitate nearly resembling the former in colour, but more copious. Muriatic acid produces the same effects as the sulphuric. Oxalic acid produces a precipitate of an orange red, nearly as copious as the nitric acid does. The liquor remains transparent, and of the same colour as in the former trials. Distilled vinegar gives a very little precipitate of the same colour: the liquor remaining transparent, and a little more inclining to orange. Tartar furnishes still less precipitate, and leaves the liquor turbid. Fixed alkali restores the decoction to a crimson, or deep violet inclining to brown. Ammoniac gives a brighter purple, or violet, and a little precipitate of a fine purple. Alum occasions a red precipitate inclining to crimson : the li quor also affords a copious precipitate on saturating the acid of the alum with an alkali. In this way an inferior
sort of carmine is prepared, and also a liquid lake for miniature painting. Alum and tartar produce a little brownish red precipitate. Sulphate of iron causes the tincture to assume a black colour, inclining to violet. Sulphate of copper produces a very copious precipitate of a still darker colour. A solution of acetate of lead causes an abundant precipitate of a pretty fine deep red. A solution of nit•o-muriate of tin gives a very copious precipitate of a fine rose colour : the liquor remaining transparent, and perfectly colourless.
132. It has been remarked, that the decoction of Bra zil wood is less proper for dyeing when fresh, than when it has been kept for some time after being prepared; and it is even said, that it answers the purpose best after it has undergone a certain degree of fermentation. Hel lot recommends the hardest water that can be procured for making the decoction : such water deepens the co lour, by means of the earthy salts which it contains. Having boiled the wood reduced into chips for three hours, the liquor is poured into a cask; fresh water is added to the Brazil, it is boiled three hours longer, and the liquor is added to the former. When the wood is used in a dye-bath, or flat, it is proper to inclose it, and indeed all colouring woods, in a thin linen bag.
133. The colouring matter of the Cxsalpinia sappan is so nearly allied in its properties and effects to that of Brazil wood, that any particular account of it is unne cessary. The principal difference between these woods, is in regard to the quantity of colouring matter which they afford. That of the best sappan wood, according to the experiments of Dr Bancroft, does not amount to one-half of that which may be obtained from an equal weight of Brazil wood, while, at the same time, it is less bright.
134. Peachwood is almost as heavy and deeply colour ed as the true Brazil wood, but it does not afford one third the quantity of colouring matter, which is both less beautiful and less durable. Some of the varieties of this wood are still more inferior in quality, and sell proportionably cheap. The best is produced near the Rio de la Hacha, eastward of St Martha, and gives near ly half as much colouring matter as Brazil wood. The Dutch have given it the name of Stock-vish-hout (stock fish-wood). Camwood, the wood of a tree imported from Africa by the Portuguese, affords a red colouring matter similar to that of peachwood, and may be treated in the same manner as a dye. Jamaica braziletto, and Bahama braziletto, probably belong to the same species, though they are usually classed as different. They af ford the least valuable of the dyeing woods, and are only employed for producing inferior and fugitive co lours.