At an interval of six feet apart, an acre of ground will contain 1,210 trees, yielding an average of 810 cwts., and 30 pounds, or above 401/2 tons of marketable matter, worth, at only L5 per ton, L200.  Should the interval between the trees be extended two feet more, we shall still have 680 to the acre, the produce of which would not improbably be increased by the increased space given for the extension of the branches.

The ground in which this tree admits of being cultivated is that which is least adapted to the staple products of tropical agriculture; guinea grass may be profitably raised beneath its shade and as with the exception of the three years which precede the commencement of its bearing, there is hardly any deduction to be made from its returns, it promises to be among the most valuable objects of a planter’s attention.

Jacquin describes the Caesalpinia coriaria as a handsome branching tree, of about fifteen feet in stature, covered with a dark spotted bark.  Its leaves are doubly pinnate, and the leaflets of twelve pair without a terminal one; they are oblong, obtuse, smooth, very entire.  The flowers are disposed in spikes issuing from the extremities of the branches; they are small, yellowish, and slightly fragrant.  To these succeed oblong, compressed, somewhat obtuse pods, curved laterally, the inner side being concave and the other convex.  The seeds rarely exceed three or four in each pod, and are of a brownish color.

Divi-divi resembles a dried pea-shuck curled up, filled with yellow powder, and a few dark brown seeds.  The price ranges from L8 to L13 per ton.

The imports into the United Kingdom in 1844, were 3,900 tons; in 1845 and 1846, about 1,400 tons each year; during the subsequent three years the imports were merely nominal, but in 1850 a renewed demand seems to have sprung up, for 2,770 tons were imported into Liverpool, and a few tons into London.

CORK-TREE BARK (Quercus suber) has been imported into Ireland to a considerable extent, frequently to the amount of 1,500 tons annually.  The quantity of cork imported annually into the United Kingdom is about 3,000 tons.  It is brought from Spain, Italy, and Barbary.  Oak bark and valonia being very cheap and plentiful, the price of cork hark is only nominal, being, for Spanish cork-tree bark, L7 10s. to L8 per ton; Leghorn ditto, L6 to L7 per ton.  It is less astringent than oak bark, and is more generally useful for stoppers of bottles and bungs for casks. 160 tons of cork-tree bark were imported into Liverpool from Rabat in 1849, and 150 tons in 1850.

1,867 cwts. of bark for tanning were imported from Chili in 1844, of which 292 were Quillai bark.

MIMOSA BARK.—­The bark of the Mimosa decurrens, which abounds in Australia and Van Diemen’s Land, is found to be a very powerful tanning agent.

The first shipment of tannin was made from Sydney to England as far back as 1823, in the shape of an extract of the bark of two species of mimosa, which was readily purchased by the tanners at the rate of L50 per ton.  One ton of bark had produced four cwts. of extract of the consistency of tar.