BENGAL STRIPES. Ginghams; a kind of cotton cloth woven with coloured stripes.
BENJAMIN or BENZOIN. (Benjoin, Fr.; Benzöe, Germ.) A species of resin used chiefly in perfumery. It is extracted by incision from the trunk and branches of the styrax benzoin, which grows in Java, Sumatra, Santa Fé, and in the kingdom of Siam. The plant belongs to the decandria monogynia of Linnæus, and the natural family of the ebenaceæ. It hardens readily in the air, and comes to us in brittle masses, whose fracture presents a mixture of red, brown, and white grains of various sizes, which, when white, and of a certain shape, have been called amygdaloid, from their resemblance to almonds. The sorted benzoin is, on the other hand, very impure.
The fracture of benzoin is conchoidal, and its lustre greasy: its specific gravity varies from 1·063 to 1·092. It has an agreeable smell, somewhat like vanilla, which is most manifest when it is ground. It enters into fusion at a gentle heat, and then exhales a white smoke, which may be condensed into the acicular crystals of benzoic acid, of which it contains 18 parts in the hundred. Stoltze recommends the following process for extracting the acid. The resin is to be dissolved in 3 parts of alcohol, the solution is to be introduced into a retort, and a solution of carbonate of soda dissolved in dilute alcohol is to be gradually added to it, till the free acid be neutralised; and then a bulk of water equal to double the weight of the benzoin is to be poured in. The alcohol being drawn off by distillation, the remaining liquor contains the acid, and the resin floating upon it may be skimmed off and washed, when its weight will be found to amount to about 80 per cent. of the raw material. The benzoin contains traces of a volatile oil, and a substance soluble in water, at least through the agency of carbonate of potash. Ether does not dissolve benzoin completely. The fat and volatile oils dissolve very little of it.
Unverdorben has found in benzoin, besides benzoic acid, and a little volatile oil, no less than three different kinds of resin, none of which has, however, been turned as yet to any use in the arts.
Benzoin is of great use in perfumery, as it enters into a number of preparations; among which may be mentioned fumigating pastilles, fumigating cloves (called also nails), poudre à la maréchale, &c. The alcoholic tincture, mixed with water, forms virginal milk. Benzoin enters also into the composition of certain varnishes employed for snuff-boxes and walkingsticks, in order to give these objects an agreeable smell when they become heated in the hand. It is likewise added to the spirituous solution of isinglass with which the best court plaster is made.
BERLIN BLUE. Prussian blue. See [Blue].
BERRIES OF AVIGNON, and Persian Berries. (Graines d’Avignon, Fr.; Gelbbeeren, Germ.) A yellowish dye-drug, the fruit of the rhamnus infectorius, a plant cultivated in Provence, Languedoc, and Dauphiné, for the sake of its berries, which are plucked before they are ripe, while they have a greenish hue. Another variety comes from Persia, whence its trivial name; it is larger than the French kind, and has superior properties. The principal substances contained in these berries are: 1. A colouring matter, which is united with a matter insoluble in ether, little soluble in concentrated alcohol, and very soluble in water: it appears to be volatile. 2. A matter remarkable for its bitterness, which is soluble in water and alcohol. 3. A third principle, in small quantity. A decoction of one part of the Avignon or Persian berry in ten of water affords a brown-yellow liquor bordering upon green, having the smell of a vegetable extract, and a slightly bitter taste.
With gelatine that decoction gives, after some time, a slight precipitate,—
| — | alkalies | a yellow hue, |
| — | acids | a slight muddiness, |
| — | lime-water | a greenish-yellow tint, |
| — | alum | a yellow colour, |
| — | red sulphate of iron | an olive-green colour, |
| — | sulphate of copper | an olive colour, |
| — | proto-muriate of tin | a greenish yellow with a slight precipitate. (See [Calico Printing].) |