This section is from the book "Materia Medica Pharmacy, Pharmacology And Therapeutics", by W. Hale White. Also available from Amazon: Materia Medica Pharmacy, Pharmacology And Therapeutics..
Asia and Southern Europe; cultivated.
A pale yellow, or light greenish-yellow, oily liquid, having a slight, peculiar odor, and a nutty, oleaginous taste, with a faintly acrid aftertaste. Sp. gr., 0.915 to 0.918.
The three constituents are - (1) Olein, 72 per cent., a fluid oil, a compound of Oleic Acid and Glyceryl, thus: C3H5(C18H33O2)3. (2) Palmitin, 28 per cent., a solid oil, a compound of Palmitic Acid, and Glyceryl, C3H5(C16H31O2)3. The formula for Oleic Acid is Hc18h33o2; and for Palmitic, Hc16h31o2. (3) Arachin, C20H40O2.
Cotton seed and other oils, especially Sesame.
Olive oil is used to facilitate the rubbing of parts; for this purpose it is employed in massage. It is a common soothing protective to burns being used in place of linseed oil in Linimentum Calcis (see p. 157), and may be mixed with poultices to prevent their adhering to the skin. If rubbed in vigorously, it can be absorbed through the epidermis, and might be thus used as a food when nourishment cannot be given by the mouth.
For its soothing protective qualities it may be swallowed after corrosive poisons have been taken. It is an excellent mild laxative, and can be given with food for this purpose. Some persons like it; with others it excites nausea and vomiting. An olive oil enema (olive oil, 15; with or without warm mucilage of starch, 18); or a soap enema (soap, 1; warm water, 32), is often used to open the bowels when a mild non-irritating injection is required. A gall stone placed in pure olive oil at the temperature of the body is slowly dissolved, because cho-lesterin, which is the chief constituent of gall stones, is soluble in olive oil. It is also soluble in oleic acid and in animal soaps. Many patients suffering from gall stones derive much benefit from taking olive oil. This is chiefly because the oil or some of its constituents are excreted by the bile, and to a much less extent because the intestinal peristalsis set up by the olive oil extends to the bile ducts. From 2 to 8 fl. oz. 60. to 240. c.c. should be taken daily. It may be mashed with fish or potato. Some patients take it better if a small quantity of menthol and a drachm 4. c.c. of brandy are added to each half pint 240. c.c. of oil. Eunatrol, or pure sodium oleate, which is given a special name to distinguish it from the ordinary impure forms, has been successfully used in cases of gall stones. Thirty to forty grains 2.00 to 2.40 gm. may be given daily. It is best prescribed as 5 gr. .30 gm. Pills.
Olive oil is a food, but it is not often used in this country as such. The history of fats and oils in the body is discussed in works on physiology.