This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Lignum Aloes, Xylaloes, & Agallochum, Pharm, Paris. Lignum Calambac. Agallo-chum, Calambac, or Aloes wood: a wood brought from China, and the inner parts of Tartary, in small pieces, compact and ponderous, of a yellowish or rusty brown colour, with black or purplish veins, sometimes purple with ash-coloured veins, and sometimes all over blackish. Of its origin, we have no very satis-factory account: most of the writers, to whom we are indebted for information about the productions of those countries, report, that it is the internal part of certain trees; that a large tree affords only a very small quantity of this valuable part; and that there are several different sorts of it, of which the best is never brought to us, being fold in China itself for twice or thrice its weight of silver.
The best sort of agallochum wood brought into Europe, has a bitterifh refinous taste, and a light aromatic smell. Set on fire, it seems to melt like wax, and emits, during the burning, an agreeable fragrance, which continues till the wood is wholly consumed. It is this sragrance in burning which makes the wood precious in the eastern countries for fumigations, and which affords the furest criterion of its genuineness and goodness. As this wood is apparently very resinous, rectified spirit takes UP more from it than watery menstrua: according to Cartheuser's experiments, an ounce yields with spirit three drams of extract, and with water only two. The watery decoction and extract are moderately bitter and subacrid. The spirituous make less impression on the organs of taste, being less dissoluble in the mouth, or less miscible with the saliva: the pure resin, obtained by precipitation with water from the somewhat infpiffated spirituous tincture, as directed by the faculty of Paris, is still weaker in taste. Hoffman observes, that in distillation with water, it yields an essential oil, of a whitish colour, of a thick consistence, of great fragrance, but in small quantity, not exceeding half an ounce from one hundred and sixty ounces of the wood: this oil, in which the more valuable parts of the agallochum are concentrated, he recommends, dissolved in spirit of wine, as one of the best cordials and corroborants, in weaknesses of the stomach and depressions of strength (a).
In our shops, we rarely meet with any agallochum that answers the above characters. In its place have been substituted woods of an in-feriour kind, probably the aspalatbus, lignum aquilae, and calambour of authors; which are said to be woods of the nature of agallochum, but, when in their greatest perfection, far weaker.