(From the Arabic term benzoah,) called also assa dulcis, assa odorata, liquor syrenaicus, or, cyreniacus balzoinum, Gum benjamin. It is a concrete resinous juice, obtained from a middle sized tree, with leaves like the bay leaves, but not ribbed, and falling off in winter, bearing flattish nuts, the size of nutmegs, whose fleshy covering is externally rough and hairy. It is a native of the East Indies and of North America, particularly of Virginia and Carolina; but only brought from the East Indies: it grows in open ground with vigour in England. Mr. Dryander has fully ascertained this tree to be a styrax; hence it is called styrax benzoin Lin. Sp. Pi. Wildenow, vol. ii. 623, nat. order bicornes. It is the styrax foliis oblongatis acuminatis subtus tomentosis, racemis compositis longitudine foliorum Dryander. Philosophical Transactions, vol. 77, p. 308. The leaves and the bark smell like the gum; and to rectified spi rit of wine they give out a resin like the benjamin, but no resin naturally flows from it: the resin is obtained by incisions made in its trunk, about the origin of the first branches; as it runs out it is white, but soon becomes yellowish, reddish, or brownish. It is brought into Europe in brittle masses, composed partly of white, and partly of yellowish or light brown pieces. The white pieces are called benzoes amygdaloides, and are reckoned the best; they are hard, solid, shining, transparent, and possess a very fragrant smell: this gum resin hath but little taste, impressing the palate with a slight sweetishness; its smell is very fragrant if rubbed or heated, and it is less heating than most of the other balsams. Its specific gravity is 1.092; and though enumerated among the resins, it is in reality a balsam, uniting an oil with an acid: 100 parts contain 9 of acid, 5 1/2 of acidulated water, 60 of thick empyreumatic oil, 22 of brittle coal, and 5 1/2 of carbonated hydrogen and carbonic acid gas. If the oil is examined, 5 grains more of acid may be discovered. Brande Ap. Nicholson's Journal.

If pure it totally dissolves in rectified spirit of wine. By digestion it imparts to water much of its fragrance and pungency: the filtered liquor, gently exhaled, leaves a crystalline matter of a seemingly saline nature, amounting to an eighth part of the whole.

The flowers of benjamin, which is the gum sublimed, and purified, if yellow, by repeating the operation, partake of the fragrance of the resin: they dissolve in spirit of wine, and, with the assistance of heat, in water; from which they are prevented from separating, if as much sugar is added as will give the consistence of syrup to the water.

The essential oil of benjamin rises after the flowers, mixed with a little acid, and tainted with a slight empy-reuma. It is purified by re-distilling it from water: the tincture is made by digesting four ounces of benjamin with a pint of rectified spirit; the compound tincture, dignified by the names of commander's and traumatic balsam, drops of life and Persian balsam, by digesting three ounces of benjamin, two of strained storax, one of balsam of Tolu, and half an ounce of socotorine aloes in a quart of rectified spirit. The lac virginalis consists of the tincture of benjamin in water, which becomes milky, and the gum deposited is the magistery of benzoin, and is chiefly the resinous without the saline part of the gum. In the original receipt of the commander's balsam, called also jesuit's drops, balsam of Berne, and friar's balsam, the ingredients were much more numerous, and the composition seems to have been warmer and more fragrant.

Of gum benjamin, the principal use is in perfumes, and as a cosmetic. It resembles in virtues and fragrance the storax and balsam Tolu, and may be useful in asthmas and other disorders of the breast, promoting expectoration: the flowers are also a powerful errhine. The flowers may be given from ten to fifteen grains, and the tincture in doses from eighty to one hundred and twenty drops, but is chiefly used to clear the skin and give a scent to wash balls. The lac virginalis must be used when a roughness or blotches render the skin unsightly: it may be rubbed on gently every day with a soft rag.

The flowers of benjamin are manifestly a saline substance of the acid kind, of some acrimony, and stimulant power. They have been recommended as a pectoral; but Dr. Cullen has employed them in some asthmatic cases without effect: half a drachm appeared to be heating and hurtful. This is the benzoic acid of the chemists, which claims a share of our attention from its so often occurring in animal substances, though, as a medicine, it is almost, if not wholly, useless. About fourteen drachms of concrete acid may be obtained from a pound of benzoin, by Scheele's process, which is preferable to any other. Its specific gravity is 0.667. It is white; with difficulty reduced to powder; its taste sharp and pungent, subliming by heat, but not volatile in an ordinary temperature. Cold water dissolves 1/100 part of its weight, and boiling water 1/20. Benzoat of lime is found in the calculi of herbivorous animals, and in some human concretions. The benzoats have not, however, been employed as medicines. From Herms-staedt's experiments, Journal de Physique, vol. 34, it appears to contain some prussic acid. It has been reckoned among the correctors of opium; and, to prevent the latter checking expectoration, has been added to the old elixir paregoric, though without any particular advantage. It is also an ingredient in the balsamum traumaticum; and in fumigations has been employed as a corrector of foul air.