The soil in which liquorice is cultivated should be deep, light, and sandy; and the roots, which strike deeply into the ground, should be planted in rows, at the distance of a foot and half or two feet from each other. Three years elapse, after the roots are planted, before the liquorice is in perfection.
202. SAINT-FOIN (Hedysarum onobrychis) is a British perennial plant with winged leaves, somewhat pyramidal bunches of butterfly-shaped flowers, marked with red, white, and purple; and oblong, hairy pods, each containing a single seed.
This plant is cultivated in several of the farming districts of England, as food for horses and cattle; and it succeeds best on dry and chalky lands, in high and exposed situations. The seed should be sown in February or March, and, during the first year, the plants should remain untouched. In the ensuing summer a crop of hay may be obtained from them; and after this the saint-foin may regularly be mown twice every year, for ten or fifteen years. When intended for hay, saint-foin should not be cut before it is in full bloom, about the beginning of July, as otherwise the quality of the hay would be much injured. Some farmers assert that saint-foin, when cows are fed with it, both increases the quantity and improves the quality of their milk; but, in the opinion of others, the quality is rather injured than improved by it. No pasture is considered more excellent for sheep than this. Saint-foin is also sometimes sown with clover, and sometimes with barley.
203. COMMON RED or BROAD CLOVER (Trifolium pratense) is a well-known field plant, much cultivated in this country.
Clover is chiefly grown in firm and good soils, either as green food for horses and cattle, or to be cut for hay. On grass farms it is sometimes sown in conjunction with spring corn, and sometimes with ray-grass ([51]); and its utility in the fattening of cattle is well known. This species of clover grows wild, in meadows and pastures of most parts of Europe; and, in some countries, during a scarcity of provisions, the flowers have been made into a kind of bread. In Sweden the heads are used as a green dye.
204. LUCERN (Medicago sativa) is a perennial plant with small purple butterfly-shaped flowers, twisted pods, the stem erect and smooth, and the leaves in threes.
Although a wild plant in nearly every country of the temperate parts of Europe, this useful vegetable has only of late years been introduced into cultivation. It flourishes most luxuriantly in deep, rich, and friable loams, and cannot be too strongly recommended as food for cattle. The value of lucern may be considerably increased by sowing it with oats; and, though an expensive crop, it yields great profit.
205. INDIGO is a blue dye prepared from a plant (Indigofera tinctoria) with a shrubby stem, oblong, smooth, and winged leaves, bunches of flowers shorter than the leaves, and cylindrical pods slightly curved, which grows in America and the West Indies.
The culture of indigo is an object of considerable importance in the West Indian islands, and in some parts of America. The grounds appropriated to it are sown about the middle of March, in rows fifteen inches asunder. The plants come into flower about three months afterwards, and are in a state to be cut about the month of August. They are cut with a kind of reaping hook, a few inches above the root. The plants are then laid in strata, in a vat or cistern constructed of strong mason-work, and so much water is poured in as will cover them. In this state they are left to ferment, and the fluid or pulp, which is first green, afterwards becomes of deep blue colour. It is now drawn off into another vat, where it is strongly and incessantly beaten and agitated, until the colouring matter is united into a body. The water is then let off by cocks in the sides of the vat; and the indigo, after undergoing some further preparations, is cast, in boxes or moulds, into small pieces, each about an inch square, and packed up for sale. The vapour which issues from the fermented liquor is extremely injurious to the negroes who attend the process; and as peculiar attention is requisite both to this and the granulating of the pulp, many indigo-planters have failed in the manufacture of this article.
Indigo is employed by dyers, calico-printers, and paper-stainers, to an extent so great that nearly 500,000 pounds' weight of it are annually imported into this kingdom. The stone-blue used by laundresses, and the colours called Saxon-blue, and green, are made from indigo. Painters use it as a water-colour. This article is frequently adulterated with earth, ashes, and pounded slate. The genuine drug ought to be of rich, dark blue colour, approaching to black; and, when broken, should display the lustre of copper. It ought not to sink in water, nor to leave any sediment when dissolved.