Uses—Salep possesses no medicinal powers; but from its property of forming a jelly with a large proportion of water, it has come to be regarded as highly nutritious,—a popular notion in which we do not concur. A decoction flavoured with sugar and spice, or wine, is an agreeable drink for invalids, but is not much used in England.[2443]
VANILLA.
Vanilla;[2444] F. and G. Vanille.
Botanical Origin—Vanilla planifolia Andrews—Indigenous to the hot regions (tierra caliente) of Eastern Mexico, diffused by cultivation through other tropical countries. The plant, which is rather fleshy and has large greenish inodorous flowers,[2445] grows in moist, shady forests, climbing the trees by means of its aërial roots.
History—The Spaniards found vanilla in use in Mexico as a condiment to chocolate, and by them it was brought to Europe; but it must have long remained very scarce, for Clusius, who received a specimen in 1602 from Morgan, apothecary to Queen Elizabeth, described it as Lobus oblongus aromaticus, without being in the least aware of its native country or uses.[2446] In the Thesaurus of Hernandez there is a figure and account of the plant under the name of Araco aromatico.[2447]
In the time of Pomet (1694) vanilla was imported by way of Spain, and was much used in France for flavouring chocolate and scenting tobacco. It had a place in the materia medica of the London Pharmacopœia of 1721, and was well known to the druggists of the first half of the 18th century, after which it seems to have gradually disappeared from the shops. Of late times it has been imported in great abundance, and is now plentifully used, not only by the chocolate manufacturer, but also by the cook and confectioner.
Cultivation—The culture of vanilla is very simple. Shoots about three feet long having been fastened to trees, and scarcely touching the ground, soon strike roots on to the bark, and form plants which commence to produce fruit in three years, and remain productive for thirty to forty.
The fertilization of the flower is naturally brought about by insect agency. This was practised as early as 1830 by Neumann in the Jardin des Plantes at Paris, and in 1837 by Morren,[2448] the director of the Botanical Garden of Liège, since which the production of the pods has been successfully carried on in all tropical countries[2449] without the aid of insects. Even in European forcing houses the plant produces fruits of full size, which for aroma bear comparison with those of Mexico.
In vanilla plantations the pods are not allowed to arrive at complete maturity, but are gathered when their green colour begins to change. According to the statements of De Vriese,[2450] they are dried by a rather circuitous process, namely by exposing them to heat alternately uncovered, and wrapped in woollen cloths, whereby they are artificially ripened, and acquire their ultimate aroma and dark hue. They are then tied together into small bundles.
In Réunion the drying of the pods is performed since 1857 by dipping them previously in boiling water.