Chief Exports.—The following table gives the average amounts and values of the chief exports for 1900-10, and the individual figures for the remaining years to 1918.
| Year | Groundnuts tons and value | Rubber lbs. and value | Beeswax lbs. and value | Palm Kernels tons and value |
|---|---|---|---|---|
| 1900-10 Av. | 39,000 tons | 46,000 lbs. | 45,500 lbs. | 255 tons |
| £250,000 | £3,500 | £2,000 | £2,260 | |
| 1911 | 47,931 tons | 10,733 lbs. | 33,871 lbs. | 443 tons |
| £437,472 | £836 | £1,514 | £4,758 | |
| 1912 | 64,169 tons | 4,335 lbs. | 30,830 lbs. | 445 tons |
| £502,069 | £409 | £1,164 | £6,518 | |
| 1913 | 67,404 tons | 12,995 lbs. | 31,518 lbs. | 546 tons |
| £622,098 | £1,027 | £990 | £9,026 | |
| 1914 | 66,885 tons | 3,548 lbs. | 15,513 lbs. | 495 tons |
| £650,461 | £102 | £473 | £7,815 | |
| 1915 | 96,152 tons | 1,171 lbs. | 9,563 lbs. | 326 tons |
| £400,435 | £31 | £311 | £5,457 | |
| 1916 | 46,366 tons | 355 lbs. | 6,950 lbs. | 669 tons |
| £506,098 | £23 | £104 | £14,671 | |
| 1917 | 74,300 tons | 1,753 lbs. | 3,962 lbs. | 532 tons |
| £869,790 | £187 | £247 | £7,994 | |
| 1918 | 56,489 tons | 564 lbs. | 8,626 lbs. | 644 tons |
| £800,319 | £40 | £501 | £9,800 |
Note.—Cotton exports were 59,828 lbs. and 2,572 lbs. in 1904 and 1905 respectively. None has been exported since.
GROUNDNUTS.—This commodity is by far the most important exported product, and is alone subject to a duty levied by the Administration.
Uses.—The undecorticated nuts are shipped, chiefly, to the French ports and to Hamburg, for the expression of an oil of excellent quality, of which they yield on an average about 30 per cent., estimated on the weight of the raw material. This is equivalent to about 44 per cent. of the weight of the extracted kernels.
The mode of extraction in general employment in France is to grind the kernels into a fine meal, from which the first quality of oil is extracted by cold expression, yielding about 18 per cent. The meal is then moistened with cold water, and at the second expression 6 per cent. more is obtained. Both of these oils are useful for alimentary purposes. A third expression is made from the residue treated with hot water, and gives a further 6 per cent., which is chiefly employed for lighting purposes, lubricating and soap-making. The fine oils are substituted for, or mixed with, the olive-oils of commerce for salad oils, and enter into the manufacture of oleo-margarine. After these expressions of oil have been made, the meal is pressed into cakes and used for cattle-food and manurial purposes.
Classification and Description of the Groundnut Plant.—The groundnut belongs to the Sub-Order Papilionaceæ, of the Order Leguminosæ, and is termed Arachis hypogæa, Linn.
The plant cultivated in Senegal and the Gambia grows in a spreading form, with branches of from 12 to 18 inches in length, and possesses oval leaflets given off in double pairs. A large number of conspicuous yellow flowers appear from the upper leaf axils, but are not capable of fertilisation. Those springing from the lower leaf axils nearest the ground are small and generally hidden, but produce fruitful pods. After fertilisation the stems of these flowers become elongated, and are directed downwards, forcing the ovary into the ground, in which it commences to swell to the mature size, frequently penetrating to a depth of two inches beneath the surface.
The fruit is a pale straw-coloured, irregularly-cylindrical pod, with the surface of the shell pitted and longitudinally ribbed. In the Gambian variety, which is identical with the common Senegalese kind, there are usually two kernels in each pod, but three or one are also found.
The plant is of doubtful origin, but it is generally supposed that it may have been introduced into Africa from Brazil (where the genus Arachis is well represented) nearly four centuries ago, by the Portuguese slave-traders.