Active Ingredients. - Pure olive oil is unctuous, pale yellow, or yellow with a greenish tinge, very slightly odorous, and possessed of a bland and slightly sweetish flavor. The sp. gr. is 0.92. At a temperature of 38° F. it begins to congeal, and at freezing point a portion of it becomes solid. Ether dissolves half its own volume of the oil, but in alcohol it is only partially soluble, unless the alcohol be in very large proportion. The constituents, according to Braconnet, are olein, about seventy-two per cent.; and palmatine, or margarine, about twenty-eight per cent. Treated with nitrous acid, or with nitrate of mercury, it becomes a peculiar fatty solid, called elaidin. With alkalies and certain other bases, it unites so as to form a soap. Exposed to the atmosphere, it is apt to become rancid, acquiring an unpleasant taste and smell, a deeper color, and a more dense consistence, which changes are quickened by heat.

Physiological Action. - Taken into the system, olive oil is mildly laxative, emollient, and in some degree nutritive. Externally applied, it relaxes the cuticular tissues.

Therapeutic Action. - As a very gentle laxative, in cases where there is much intestinal irritation, forbidding the use of powerful medicines, olive oil may be given with the best effect. It is especially valuable, in the form of enema, for infants and young children.

In various forms of irritant poisoning, if olive oil be promptly administered it mechanically entangles much of the noxious matter, and interposes itself as a shield to the mucous surface.

It has been recommended as a vermifuge, but this can only be the case in so far as its not very powerful purgative qualities extend.

As a mechanical defence from the atmosphere for diseased cutaneous surfaces, olive oil is often very useful. The special value of olive oil in pharmacy, however, is its convenience for use in the making of liniments, plasters, ointments, and other preparations for external use.

Preparations and Dose. - Oleum Olivae, 3 j. -

Oleaceae The Olive Olea Europaea 42

(4. - 30.). It is an ingredient of: Liniment. Ammoniae; Liniment. Camphorae; Liniment. Chloroformi; Liniment. Plumbi Subacetatis; Emplast. Ammoniaci cum Hydrargyro; Emplast. Hydrargyri; Emplast. Plumbi; Ceratum Cetacei; Ceratum Plumbi Subacetatis; Ceratum Saponis; Charta Can-tharidis.