b. (Thomson.) Oxide of zinc, 1⁄2 dr.; powdered opium, 5 gr.; lard, 1 oz. As the last, when there is much pain.
Ointment of Zinc, Cyanide (Cunier). Syn. Unguentum zinci cyanidi. Prep. Cyanide of zinc, 12 grains; lard, 5 drams; butter of cacao, 5 drams. Mix.
OINTMENTS (Flower of). Syn. Flos Unguentorum, L. Prep. From resin, thus, wax, and suet, of each 1⁄2 lb.; olibanum and Venice turpentine, of each 21⁄2 oz.; myrrh, 1 oz.; wine, 1⁄2 pint; boil them together, and, lastly, add of camphor, 2 dr. Suppurative; warming.
O′LEFIANT GAS. C3H4. Syn. Ethylene, Heavy carbonetted hydrogen, Heavy carburetted h., Elayl, Ethene. A substance discovered by some associated Dutch chemists, in 1795, and composed of carbon and hydrogen in the proportions expressed by C2H2 or C4H4.
Prep. 1. A mixture of alcohol (rectified spirit), 1 part, and oil of vitriol, 6 parts, is heated in a retort until it blackens, and sulphurous acid begins to be evolved; the product is then passed first through a wash-bottle containing a solution of caustic potassa or milk of lime, and next through a bottle containing concentrated sulphuric acid, the last being furnished with a tube dipping into the water of the pneumatic trough.
2. The vapour of boiling alcohol is passed into a mixture of oil of vitriol diluted with rather less than one half its weight of water, and so heated as to be in a state of tranquil ebullition (320° to 330° Fahr.); the gaseous product is chiefly olefiant gas, and the vapour of water, from which it may be separated as above. No sulphurous acid is formed, nor does the acid blacken as in the last process.
Prop., &c. Colourless; neutral; nearly
odourless; nearly insoluble in water; alcohol, ether, and the volatile and fixed oils, absorb a portion of it; burns with a brilliant white flame; at a full red heat it suffers decomposition, with deposit of carbon and liberation of light carburetted hydrogen gas; mixed with twice its volume of chlorine and inflamed, hydrochloric acid is formed, and the carbon of the gas is precipitated in the form of dense black soot; if the mixture (best in equal volumes), instead of being kindled, be left standing over water, it soon condenses into a heavy oily liquid (chloride of olefiant gas, Dutch liquid). Sp. gr. ·981; 100 cubic inches weigh 30·57 gr.
Olefiant Gas, Bromide of. Syn. Bromide of ethylene. From bromine and olefiant gas as Dutch liquid. A colourless liquid, with an ethereal odour, boiling at 265°, and solidifying at 0° Fahr. Sp. gr. 2·16.
Olefiant Gas, Chlo′′ride of. Syn. Dutch liquid, Chloride of ethylene. This substance, referred to above, may be easily prepared in any quantity by the following process:—Chlorine and olefiant gas (the latter a little in excess) are conveyed by separate tubes (passing through the same cork) into a glass globe, having a narrow funnel-shaped neck at its lower part, dipping into a small bottle destined to receive the product of their mutual reaction: the newly formed liquid trickles down the sides of the globe into the receiver, and when a sufficient quantity is collected, it is purified by agitating it first with water, and then with sulphuric acid, and, lastly, submitting it to distillation.