Benzoin is the concrete juice of Styrax Benzoin, a stately tree, growing in Java, Sumatra, Borneo, Siam, and other parts of the East Indies. It is obtained by wounding the bark, and collecting the juice as it exudes. This soon hardens on exposure.

There are two prominent varieties of benzoin; one either in separate whitish tears, or masses consisting of aggregated tears with a reddish-brown connecting medium; the other in masses of a brown colour, with few or no tears.

The odour of benzoin is fragrant; its taste very slight, but somewhat acrid after chewing. It is fusible and inflammable, and when melted emits pungent fumes. It consists chiefly of resin and benzoic acid, and, when heated in close vessels, gives out benzoic acid with a fragrant volatile oil. It yields a small proportion of benzoic acid to water, and is wholly soluble in alcohol.

Medical Effects and Uses

Benzoin is moderately stimulant and expectorant; but is almost never used by itself internally. It may be employed advantageously, by way of fumigation, in chronic inflammation of the larynx with ulceration, and in chronic bronchitis; portions of it being thrown upon burning coals so as to impregnate with its vapours the air of the chamber, in which the patient may be placed The object aimed at should be to keep the air constantly fumigated, but only to such a degree as may be quite comfortable to the patient, without exciting cough. The balsam may also be used by adding it to boiling water, and inhaling the vapour by means of an inhaler. (See vol. i. p. 75.) There are two preparations of benzoin which are more or less used in medicine.

Compound Tincture of Benzoin (Tinctura Benzoini Composita, U. S., Br.) is prepared by dissolving benzoin, storax, balsam of Tolu, and aloes in officinal alcohol. The resinous matter of this tincture is separated on the addition of water. It is sometimes used as a stimulant expectorant, and slight laxative, in old pectoral diseases, in doses varying from thirty minims to two fluidrachms. Mr. R. W. Ellis, of Bristol, England, has found it very useful in chronic dysentery, in the dose of fifteen or twenty minims three times a day. (Braithwaite's Retrospect, No. xxiv. p. 101.) Its chief employment, however, is as a stimulant apvol. ii. - 44 plication to old and indolent, or flabby ulcers. it has proved serviceable in chapped nipples.