Source, Etc

The oil expressed from the seeds of Ricinus communis, Linne (N.O. Euphorbiaceoe). See p. 182.

Description, Etc

Nearly colourless, viscous, slight odour, acrid unpleasant taste. Specific gravity 0.958 to 0.970; iodine value 83 to 90; acetyl value about 150; soluble in all proportions in absolute alcohol and in 3.5 parts of alcohol (90 per cent.); consists of the glycerides of ricinoleic, isoricinoleic, stearic and dihydroxy-stearic acids. Its freedom from admixture with other fixed oils is shown by the petroleum spirit test: 10 c.c. with 7 c.c. of petroleum spirit form a clear mixture at 15.5°; on adding a further 3 c.c. of petroleum spirit the mixture becomes turbid, on warming to 21° clear, and on cooling to 18° again cloudy.

Uses

A mild purgative; on account of its viscosity largely used, especially in warm climates, as a lubricant.

Note

Turkey red oil is obtained by allowing sulphuric acid to run slowly into castor oil, kept cool, washing with water and solution of sodium sulphate and adding ammonia until a clear water-soluble liquid is formed; the ricinoleic acid is converted into ricinoleo-sulphuric acid. It is largely used in dyeing cotton, imparting to the fabric a better lustre.