The volatile oil is described on p. 1416.
Soy.—This useful condiment, said to form the basis of almost all the popular sauces made in Europe, is prepared by the Chinese and Japanese from the fruit of Glycin,e Soja [Soja hispida], which holds an important place among oil-yielding plants, and has been described under the article on Vegetable Fatty Oils (p. 1378). The condiment is prepared by boiling the beans with an equal quantity of roughly-ground barley or wheat, and leaving it covered for 24 hours to ferment ; salt is then added in quantity equal to the other ingredients, water is poured over, and the whole is stirred at least once daily for two months, when the liquid is poured and squeezed off, filtered, and pre served in wooden vessels, becoming brighter and clearer by long keeping. Its approximate value in the London market is 2s. 3d.-3s. a gal. fur Chinese, and 2s. 4d.-2s. 5d. for Japanese. It is not specified in the trade returns, but doubtless forms the chief item in the uuenumerated spices imported from China.
Vanilla Vs., Vanille ; GER., Vanille).—This name is applied to the pods of one or more species of Vanilla, the bulk of the commercial article being probably derived from V. planifolta [sativa, Myrobroma fragrans], a native of Mexico, now largely cultivated in many tropical countries, as will be preeeutly described. Other species eaid to afford the spice are :— V. sylocstris, Mexioo, perhaps identical with V. planifolia ; V. Pompona, in Mexico; V. guianensis, ia British and Dutch Guiana ; V. palmarum, in Bahia ; V. aromatica, in Brazil and Peru.
The culture and preparation of vanilla are subject to some variation in different localities. Iu Mexico, plantations are eetablished in virgin forests or open fields. In the former, all shrubs, climbers, and trees causing an excess of shade are cut down, leaving only young trees.to serve as supports fer the climbing etems of the vanilla plant. Preference is given to those containing a milky sap, as the plant attaches itself to the bark by means of aerial roots, produeed from the nodes, and constituting ite true organs of nutrition, for the subterranean roots are quite inaignifleant, and often suffer gradual decay. Close to eaeh supporting tree, two vanilla euttiugs are planted side by side in the following manner ; the entting is embedded in a trench in. deep and 15-20 in. lung, as far as 3 joints or eyes, the 3 leaves having been first stripped off, and then covered with dead leaves, humus, coaree sand, brush-wood, &c., the bed being slightly raised above the surrounding
level, to prevent stagnation of water around the plant. Thu remainder of the cutting, 3-4 ft. long, is tied up to the tree. The trees should be 12-15 ft. apart, to allow room for the rapid growth of the plants. After 1 month, the cuttings will have takeu root, and need to be carefully freed from weeds and underwood ; in the 3rd year, they bear fruit. When planting a field or open level ground, the land is firet ploughed up and sown with maize. Meantime a number of young Jae tescent trees of the fig tribe spring up all over the field, and, in 12-18 mouths, are eapable of sup porting the vanilla-plants, which are then set out as already described. The fiuest product is obtained in tbie way.
In Reunion (Bourbon), where artificial fecundation is practised, the plants are not allowed to grow out ef reach. When starting a plantation in a forest, the cuttings are aet at the feet of the trees, whose trunks are connected transversely by a rude trellis ; the trees are never lopped, as vanilla requires humidity, and protection frum the direct rays of the eun. In making a plantatiou in an open field, the first care is to g-row supports for the plants. Mangoes and fig-trees are employed for this purpose, though preference is given to Curcas purgansVatropha Camas], the physic nut, whieh strikes readily from cuttings, is of rapid growth, and furnishes abundance of milky juice as sustenance for the vanilla-plant ; but Holmes has indicated the posaible danger of the acrid matter contained in the juice of this tree (see Nuts, p. 1359 ; Oila, p. 1410) being absorbed by the vanilla-plant. When the youog supporting treea have attained aufficient growth to shade the vanilla, cuttings of the lattur are planted as follows :—A trench 8 in. deep is chm between the trees and along the lines in which they grow ; the cuttings are set ia it, and covered with a little humus, dead leaves, and straw. The rainy season is selected for the operation. When the young shoots begin to grow, it is only necessary to guide them along the trellisea, and allow the aerial roots to rejoin the trench between the aupporting trees ; in 2 years, the plantation is in full bearing.