CASTOR-OIL is procured from the Ricinus Conmumis, or Castor-oil plant, which was known from very ancient times both to the Egyptians and to the Greeks. The native country of the Bicinus comniunis is unknown, though it is conjectured to bo originally from Barbary. The entire plant is possessed of ac. tire properties, but the oil extracted from the seeds is only employed in Europe. The an cients administered the seeds entire, but their variable action, occasionally even producing fatal effects, led to their disuse, and the oil is of comparatively recent introduction. The seeds, of which three are found in each cap sule, are about the size of a small bean. They were formerly known in the shops as Semina Ricini. Various procedures have been adopted to extract the oil, and these have much influ ence on its qualities in respect of colour, acri dity, and freedom from rancidity. Both in India and America, whence the first supplies were brought, much heat was employed, and during the process a volatile principle was either liberated or produced, which was so irri tating as to require the workmen to protect their faces by masks. Even in the present
day some heat is used to obtain what is termed the cold drawn castor-oil, but it is quite unne cessary, and should always be avoided.
Castor-Oil of good quality is a thickish fluid, of a very pale yellow colour, almost limpid, with a slightly nauseous odour, and an oily taste, mild at first, but causing a feeling in the back of the throat, which is more or less in tense in proportion to the freshness of the specimen. Old or badly-prepared oil is rancid and disagreeable. It can be solidified only by a very low temperature.
Castor Oil is a valuable and well-known me dicine, of which considerable quantities are used. The quantity imported in 1848 was no less than 4588 cwts.