The benzoin received into British commerce is primarily distinguiahed as " Siam" and " Sumatra," each sort exhibiting variety of purity and appearance. The best of the former coneists of an agglutinated mass of flattened, opaque, milk-like tears of white resin ; oftener it reveals white, almond-like fragments embedded in an amber-brown translucent matrix, and the white tears are occasionally very minute, or almost altogether wanting. These latter have a stratified structure, including tranelucent layers. The mass is brittle, with a vanilla-like odour, but little flavour, aud is readily softened by heat [fusing-point, 75° (167° F.)]. The Sumatra article has a generally greyer tint than the Siam, but when good, exhibits raany opaque teara in a translucent greyish-brown body, the tears diminiahing as the quality declines. The odour is lest; powerful and pleasant than that of the preceding. The tears melt at 85° (185° F.) ; the greyish brown mass, at 95° (203° F.). Both kinds contain an admixture of fragments of wood, bark, and other foreign matters. Tbere also appears in the London market at intervala a variety of benzoin, locally distinguished as " Penang or storax-smelling benjamin," having a highly fragrant odour, quite distinct from the ordinary kinds. The source of thia ie a matter of obscurity.
The chief mart for benzoin is Singapore. The imports here in 1871 were 6185 cwt. from Sumatra, and 405 cwt. from Siam ; the exports in 1877 were only 1871 pieuls (2227 cwt.). Penang, in 1871, received 4959 cwt. from Sumatra for re-export. Padang (Surnatra) exported 4302 picids (5122 cwt.) in 1870, and 4064 pietas (4838 cwt.) in 1871. Bombay imported 4902 cwt. from the Straits Settlements in 1872-3 ; the exports in the same year were :-1903 cwt. to the United Kbagdom, 198 to the Persian Gulf, 134 to African coast, 37 to Aden, 26 to the Red Sea, and minor quantities to Turkey, Mekran, France, &c.
The principal application of the resin is in perfumery and as an incense for ohurch use (see Perfumes). Lesser quantities of it are used in various compositiona to prevent rancidity in fats ; it is alao the source of benzoic acid, employed in perfurnery and medicine, and is an ingredient of black aticking-plaister, and the base of Friara'-balaam. The approximate London market valuea of benzoin are as follows :- Siam, 2ncl and 1st, 10-70/. a cwt. ; Sumatra, 2nd and 1st, 5-15/.; 3rd, 2i.-11. 15s.
Other products which may be mentioned here are the aromatic resins afforded by Terminalia Benzoin in India, and by T. mauritiana in Mauritina. The former is esteemed as a coametic, and the latter as incense, but neither appears in commerce beyond the immediate neighbourhood of the locality producing it. Probably some misapprehension underlies the statement that benzoin; obtained from Styrux Benzoin, has recently been sent in some quantity from the Brazilian province of Bahia.
Cadjii or Cashew (FR., Gomme d'acajou; GER., Anaoardium-gummi).—This gum is obtained
by wounding the trunk and branches of Anacardium occidentale, the tree affording cashew-nuts (see Nuts, p. 1352), and two kinds of oil (see Oils, p. 1379). The gum is collected in Martinique, Guadaloupe, Brazil, India, and Burma. In India, the incisions are naade while the aap is rising. The gum usually occurs in elongated stalactitic pieces, or cylindrical tears, varying in colour from dirty-white to dirty-brown, the S. American being mostly topaz-yellow to brownish-red. It is sub-astringent, and highly unpalatable to insects. It consists principally of arabine and dextrine, both soluble in water, with a minor insoluble portion, probably baasorine. It forms a strong, yellowish mucilage with water. In S. Arnerica, it ia largely used by book-binders; it is occasionally imported from that continent into this country, and poasesses the same commercial value as the common and inferior sorts of Arabic and Sent gal gums (see pp. 1630-1).
Camphor, pp. 571-8.
Canada Turpentine—Canadian, p. 1686.
Chagual or gum is afforded by one or more S. American species of Puya [Pourretia]; P. coal-data of Chili, and P. lanuginosa of Peru, have been more particularly indicated as its sources. The exudation is said to be caused by punctures from a caterpillar (Castnia elegans), the gum hardening on the stem, and occurring in commerce in cylindrical pieces, whoa() inner aurfaee generally exhibita fragments of parenchyma, aud whose aize implies a diameter of in. in the sterna on which the gum has concreted. The fracture of the gum is conchoidal ; its colour, topaz-yellow ; its hardness, about the same as gum arable ; ita tenacity, aomewhat leaa than tragacanth ; ita density, when air-dry, 1.866. It is exceedingly rich in bassorine, only about 16 per cent. of it being soluble in water.
Cherry (Fs., Gomme clu pays ; GEL Kirschgummi).- "Cherry-guin" is a term applied very Indefinitely to the gummy exudations of cherry, plum, apricot, almond, and other trees, Included in the genera Priem, Cerasus, and Amyqd das. The secretion of the gum takes place in the wood of these trees, as well as in the bark. The masses of this gum aro usually sub-globular or reniform, and often of considerable aize. The fracture is eenchoidal and atrongly lustrous; the colnur rane.es from pale-yellow to brown, the plum-gum being generally light while the cherry-gum is darker; the gum is brittle, but less easily pulverized than the Acacia-gums ; its flavour varies from sweet to astringent, but is always insipid. The aelubility in water is not complete in any variety. The peach and almond kinds are least soluble, containing but little arabine ; cherry contains about 52 per cent. arabine, and 35 cerasine. These gums are not commercial articles in England, nor in Germany of late years, but oontitiue to have some importance in French industry, those mostly employed being from cherry and plum trees.