the fruit of Citrus Limonum (see Botany, Index), is a native of Asia, and was brought to Europe by the Crusaders. Like most of its tribe, the lemon produces under cultivation a great number of varieties. Several are known in commerce. The principal are,—the Wax Lemon (Citrus Limonum ceriseum of Risso); this is the smooth-peeled one, most generally found in the markets; its rind is thick. The Bignette Lemon (Citrus Limonum Bignetta of Risso) is a thinner-peeled fruit than the wax lemon, less oval in shape, and more blunt at the point; the colour of the rind is less clear, and is usually tinged with green. It is cultivated more largely than any other variety, as it yields a larger quantity of juice, and is a most abundant bearer. The Clustered Lemon (Citrus Limonum racemosum of Risso) is the least oval of the imported lemons, but the nipple-like point is fully developed. The rind is thick, and has a bright yellow colour. The pulp is less agreeable than the varieties previously mentioned. One or two other varieties, as the Imperial and Gaeta lemons, are occasionally brought to this country, but not in any considerable quantities.

The lemon is extensively cultivated in Sicily, Italy, Spain, Portugal, and the S. of France. By far the greater number imported come from Messina and Palermo. The average imports into Great Britain are about 4000 boxes, or 5000 bushels.

Besides the fruit, the rind of the fruit comes either pickled in salt or already candied. From Sicily, Naples, and Lisbon we receive nearly 70,000 lbs. of the essential oil of lemon, yielded so abundantly by the flavedo of the peel. In order to obtain it, the flavedo is grated off, and being put into a horse-hair bag, a yellow turbid oil is forced out by pressure; this, after standing some time, deposits a thick sediment, and is then decanted and afterwards filtered.

Lime juice is another of the products of the lemon, and is of great value as a preventive and cure for scurvy. It is received either fresh, as expressed from the fruit, in which state it is a turbid light yellow coloured liquid; or in a state of concentration from boiling. This concentrated lime juice is a thick coffee-brown coloured liquid, and is chiefly consumed in the manufacture of the crystallized citric acid, which exists in greater abundance in the lemon than in any other fruit.

Citric acid is separated from the juice with great ease, owing to the readiness with which it enters into combination with chalk, forming citrate of lime. To this sulphuric acid is added, and forms the insoluble sulphate of lime, from which the citric acid is easily obtained by washing, and subsequent crystallization. Citric acid used in the manufacture of various pharmaceutical preparations, in combination with iron, quinine, potash, &c.

LEMSON, Salt of, a term improperly applied to bin-oxalate of potass, or salt of sorrel. It is prepared, in Switzerland and the neighbouring countries, from wood-sorrel; about 60 or 70 lbs. of the mature plant yielding about 5 oz. of the crystallized salt. Some persons, deceived by the vulgar name, have used this substance to acidulate punch; but it is a dangerous practice, for the binoxalate of potass is an active poison. It is best known in this country as a means of removing ink-spots from linen. When an ink-spot is washed with an alkaline soap, it forms a yellow iron-mould, as it is called, in consequence of the oxide of iron, which is the basis of the ink, attaching itself to the cloth, while the tannic acid of the ink is removed by the alkali of the soap. The oxalic acid of the binoxalate of potass unites readily with most of the metallic oxides; and in the case of an iron mould, forms a colourless oxalate of iron, which being soluble, is readily removed from the linen.