Obs. The above is the oil of ergot now employed in medicine. It must not be confounded
with other preparations occasionally called by the same name, but which differ from it in character. Among the latter are the following:
a. A fixed oil obtained by distilling off the spirit from the alcoholic tincture. It has the odour of rancid fish oil, and the distilled spirit has also a putrid odour.
b. A fixed oil, obtained from coarsely powdered ergot by strong pressure between iron plates, at a heat of about 212° Fahr. It is fluid, coloured, smells strongly of the drug, but is nearly destitute of its leading qualities. Both the preceding contain some volatile oil and resinous matter.
c. An empyreumatic oil obtained by distilling ergot per se. It is light brown, viscid, acrid, and nauseous.
d. A volatile oil obtained by digesting powdered ergot in solution of potassa at 125° Fahr., diluting the saponaceous mass thus formed with one half to an equal weight of water, neutralising the alkali with dilute sulphuric acid, and then submitting the whole to distillation in a chloride of sodium or oil bath. It is white, adhesive, butyraceous, and tasteless. It appears a product, rather than a simple educt.
e. This is the ethereal oil, first described, in its purest form. It is colourless, translucent, oily, and acrid-tasted, with the odour of ergot; it has a high boiling-point, at which it suffers partial decomposition, but may be volatilised at a lower temperature, like the other oils. By long exposure to heat, it thickens and partly solidifies; light and air darken it; it is lighter than water, very slightly soluble in water, but sufficiently so to impart to it its peculiar odour; it is soluble in pure alcohol, in ether, the volatile and fixed oils, alkaline lyes, liquor of ammonia, creasote, and naphtha. The dilute mineral acids clear it but do not produce any marked reaction.
Oil, Ethe′′real. See Oil of Wine (below).
Oil of Eucalyptus. Syn. Oleum eucalypti globuli. See Eucalyptus.
Oil of Fen′nel. Syn. Oleum fœniculi (Ph. L.), O. f. officinalis (Ph. E. & D.), O. f. dulcis, L. From the fruit or seed of Fœniculum dulce, or sweet fennel (Ph. L.), Colourless; odour that of the plant; tastes hot and sweetish; congeals at 50° Fahr.; carminative and stomachic. It consists of two oils; the one solid and identical with that of oil of aniseed. When treated with nitric acid, it affords benzoin, Sp. gr. ·997. Prod. Dried fruit (of commerce), 3% to 3·5%. The flowering herb yields ·35% of a similar oil.