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. About 1840 groundnuts began to attract the attention of European manufacturers, on account of the value of the oil obtained from them, and, in common with the Senegalese, the Gambian natives were induced to undertake cultivation upon a large scale. The nuts grown in the Gambia and in Saloum, in the French territory adjoining on the north, are classed as of second quality; those from Cayor and Rufisque holding the first, and those from the Casamance and Portuguese Guinea the third, places.