444 MEDICAL BOTANY. 



or somewhat fermented, and then re-pressed, by which is obtained a coarse oil, 

 fit only for soap-making or for burning. At Gallipoli, where a large quan- 

 tity of oil is made, principally for manufacturing purposes, the several opera- 

 tions are conducted in a very rude manner, and the oil obtained is of the 

 coarsest kind, and is kept in large cisterns dug out of the rocks, until wanted 

 for exportations [Ulysses' Travels). This is also generally the case in Spain, 

 where the olives are beaten from the trees, and the ripe and unripe, sound 

 and decayed, thrown together into a heap to ferment, then ground and press- 

 ed ; by these means a large product is obtained, but it is rank and disagree- 

 able. 



According to De Candolle, one hundred pounds of olives afford about thirty- 

 two pounds of oil, of which twenty-one is from the pulp, the remainder from 

 the seed and woody portion of the nut. When first made, it deposits a white 

 fibrous matter, formerly employed in medicine under the name of amurca. 



The best table oil comes from the South of France and Tuscany. When 

 good, it is an unctuous fluid, of a pale yellow or greenish-yellow colour, with 

 scarcely any odour, and a bland and almost mucilaginous taste. When ex- 

 posed to a temperature of 32°, it congeals and separates into two portions, 

 one solid, called Margarine by Lecanu, and Stearine by Chevreul, and the 

 other fluid, called Elaine or Oleine. It is composed of about 72 parts of the 

 latter and 28 of the former. Olive oil is often adulterated, especially with that 

 from the poppy, and of late years, it is said, very largely with lard oil ; several 

 plans have been proposed to detect these adulterations, the most simple of 

 which is the exposure to cold, as the pure oil will solidify when cooled with 

 ice, which neither of the adulterating oils will do. If the oil be adulterated 

 with lead, which is sometimes the case, to obviate its rancidity, it may be de- 

 tected by shaking one part of it with three parts of water impregnated with 

 sulphuretted hydrogen, when a precipitate of the lead will ensue. 



Medical Properties. — The medicinal qualities of olive oil are those of a 

 nutrient, demulcent, emollient, and laxative. In catarrh and other pulmonary 

 affections, it has been used as a demulcent in the form of an emulsion, but 

 the oil of almonds is more generally employed in such cases. It is also oc- 

 casionally recommended as a mild laxative, where there is much irritation of 

 the intestinal mucous membranes ; and as an antidote against certain poisons, 

 among the rest where cantharides had been taken ; but as it is an excellent 

 solvent of the active principle of this drug, it augments the danger instead of 

 mitigating it. Nor is it proper incases of poisoning with opium or its salts, 

 with arsenic, copper, &c, in which it has been recommended, but is highly 

 beneficial where poisonous doses of the alkalies have been taken, as it forms 

 a soap with them. 



Olive oil has enjoyed much reputation as an external remedy in the plague, 

 and according to Mr. Jackson [Hist. Morocco), is of the greatest benefit, not 

 only as a preventive but as a curative means, after the accession of the dis- 

 ease ; but the trials made with it by several practitioners do not confirm his 

 statement of its powers. It was also considered as an antidote against the 

 bites of venomous serpents, but there are no just grounds for supposing that 

 any reliance is to be placed upon it. 



It is principally employed in the composition of liniments, ointments, ce- 

 rates, and plasters, and is also frequently prescribed as a constituent of laxa- 

 tive enemata, where there is irritation of the lower bowels or adjoining parts. 

 Its use as an article of food, or in the arts, is too well known to require com- 

 ment, except to state that it is always improper for persons suffering from 

 dyspepsia. The dose, when it is intended as a laxative, is from a drachm to 

 an ounce or more. 



