172 OLEA EUROP^EA 



yellow or greenish-yellow colour, with a very faint agreeable 

 odour, and when fresh having a bland oleaginous taste, but by 

 long keeping it becomes slightly acrid. Its specific gravity varies 

 somewhat, averaging at 63 Fahr. O916. Olive oil is but very 

 slightly soluble in alcohol, but it is soluble in about twice its 

 volume of ether. The finer kinds of oil do not readily become 

 rancid by exposure to the air, but the second qualities soon 

 become so. At about 36 Fahr. olive oil begins to congeal, and 

 at about 21 it separates into two portions, one solid, consisting of 

 about 28 per cent, of the whole, which is commonly termed marga- 

 rine ; and the other fluid, forming about 72 per cent., and called 

 oleine. The finer qualities of oil contain most oleine. Oleine by 

 saponification yields oleic acid and a sweet principle termed gly- 

 cerine ; margarine also yields by saponification glycerine and mar- 

 garic acid, which latter is sometimes regarded as a mixture of stearic 

 and palmitic acids. Olive oil is not a drying oil, and therefore 

 does not readily increase in consistence by exposure to the air. 



Medical Properties and Uses. Olive oil is demulcent, and in 

 large doses mildly laxative. It is a frequent constituent of laxative 

 enemas, especially when they are used in affections of the bowels. 

 It is also employed as an antidote in cases of poisoning ; it acts 

 by enveloping the poison, sheathing the living surface, and thus 

 mechanically obstructing absorption. Externally applied it is 

 sometimes useful in preventing, or at least relieving, the ill effects 

 produced by the sting of a wasp or bee. Thus, Dr. F. J. Farre 

 says that " the obstruction which it causes to the absorption of 

 poison is often very serviceable, and is sometimes sufficient to 

 prevent any bad effects from following. I have often applied oil 

 to the recent sting of a wasp or bee even after the pain had 

 extended from the wounded finger to the entire arm, and have 

 always found the pain cease after a few minutes. It has some- 

 times returned for a day or two immediately after washing the 

 hands until oil was again applied to the wound." Olive oil is chiefly 

 used externally, however, as an emollient vehicle for liniments and 

 other external applications. It has also been applied externally 

 in skin diseases to relieve pruritus ; and in burns and scalds to 



