When ground-nut oil is treated with hyponitric acid, which may be most conveniently evolved by heating nitric acid with a little starch, a solid mass is obtained, which yields by crystallization from alcohol Elaïdic and Gæidinic acids, the former isomeric with oleic, the latter with hypogæic acid.
Production and Commerce—The pods are exported on an immense and ever increasing scale from the West Coast of Africa. From this region, not less than 66 millions of kilogrammes, value 26 millions of francs (£1,040,000), were imported in 1867, almost exclusively into Marseilles. From the French possessions on the Senegal, 24 millions of kilogr. were exported in 1876.
The oil is exported from India where the ground-nut is also cultivated, though not on so large a scale as in Western Africa. In Europe it is manufactured chiefly at Marseilles, London, Hamburg and Berlin. The yield of the seeds varies from 42 to nearly 50 per cent. The softness of the seeds greatly facilitates their exhaustion, whether by mechanical power or by the action of bisulphide of carbon or other solvent.
Uses—Good arachis oil may be employed in pharmacy in the same way as olive oil, for which it is a valuable substitute, though more prone to rancidity. It has been introduced into the Pharmacopœia of India, and is generally used instead of olive oil in the Indian Government establishments. Its largest application is for industrial purposes, especially in soap-making.
RADIX ABRI.
Indian Liquorice; F. Liane à réglisse, Réglisse d’Amérique.
Botanical Origin—Abrus precatorius L., a twining woody shrub[747] indigenous to India, but now found in all tropical countries.
History—The plant is mentioned in the Sanskrit medical writings of Susruta, whence we may infer that it has long been employed in India. Its resemblance to liquorice was remarked by Sloane (1700), who called it Phaseolus glycyrrhites. As a substitute for liquorice, the root has been often employed by residents in the tropical countries of both hemispheres. It was introduced into the Bengal Pharmacopœia of 1844, and into the Pharmacopœia of India of 1868.
The seeds, of the size of a small pea, well known for their polish and beautiful black and red colours, have given their name of Retti to a weight (= 2³/₁₆ grains) used by Hindu jewellers and druggists.
Description—The root is long, woody, tortuous and branching. The stoutest piece in our possession is as thick as a man’s finger, but most of it is much more slender. The cortical layer is extremely thin and of a light brown or almost reddish hue. The woody part breaks with a short fibrous fracture exhibiting a light yellow interior. The root has a peculiar, disagreeable odour, and a bitterish acrid flavour leaving a faintly sweet after-taste. When cut into short lengths it has a slight resemblance to liquorice, but may easily be distinguished by means of the microscope.