Page:The New International Encyclopædia 1st ed. v. 14.djvu/901

OILS. 769 OINTMENT. ■which the heavy vapors are withdrawn from the still.s as soon as foruied, 'cracking' does not take phue and the residuum may be used entirely lor preparing lubricating oils and vaseline. Dur- ing Ihe "cracking,' which is facilitated by heat- ing the stills over free fires, the residuum is de- composed and jields a further series of volatile products (chielly used as burning oils), together with paraffin, lubricating oil, ycdlow 'wax,' and coke. Kussian oils may be successfully treated by a continuous process of distillation, as they are not very susceptible to cracking. To guard against any possibility of change, the stills are heated by su]ierhcated steam. Oils containing large quantities of sulphur are very offensive and must be distilled over mixtures of oxides of cop- per and lead to take up the sulphur, before they can be refined. The crude oil is, however, now largely used for fuel purposes with steam or compres.sed air in injector burners. The follow- ing mineral oils are commercial articles: J'clroleuiii Etlicr, distills over between 40° and 70° C {104° and 158° F.), and is used as a sol- vent and for gas machines. Cusolene, distills over between 70° and 90° C. (158° and 194° F. ) , and is used as a .solvent and for carbureting coal-gas. Xtiphtha, distills over between 80° and 110° C. (170' and 230° F.), and is used for burning in vapor stoves, and as a solvent for resins. Benzine, distills over between 120° and 150° C. (248° and 302° F.), and is used as a substitute for turpentine for cleaning clothing. Kerosene. See article Petroleum. Luhricatiny Oils, including spindle oils and cylinder oils. The analytical tests applied to these oils include determinations of specific gravity, the 'fire test' (i.e. determination of the fiash-point and burning-point), the cold test, and determinations of viscosity and neutrality. For burning oils the fire test and tlie determina- tion of neutrality are the most important. For lubricating oils the determination of viscosity is also essential. A large number of forms of ap- paratus have been devised for obtaining the fiash and burning point, but no other is as simple and reliable as the New York State 'closed tester.' This apparatus consists of a doul)le boiler of copper heated by a gas or lamp llamc, the inner chamber being filled with oil and covered with a glass plate perforated with two holes, one for the thermometer, the other for the introduc- tion of the test flame. The oil must not be heated more ra|)idly or slowly than 2° F. per n>inute. At minute intervals the test flame is brought to the hole in the glass cover. A flash is said to occur when a blue flame momentarily plays over the surface of the heated oil, and at this point the tliermometer is road. The burn- ing-point, ustially a few degrees higher, is that tem]ierature at which the oil begins to burn. Previous to the introduction of petroleum products, bituminous shale had been subjected to destructive distillation, yielding gas, ammonia, oil. and tar. This process is still carried out in Scotland, Germany, and various other Kurnpean countries. Oil does not occur as such in bitumi- nous shale, but is liberated by the decomposition of the latter, which is a sort of piteli. Shale, in small pieces, is fed into vertical retorts heated to a low red heat, and steam is injected into the retorts to promote distillation. The vapors are condensed in a hvdraulic main and scrubbers similar to those employed in the distillation of coal (see Gas, Illlmi.nating) , the gases given oil' being utilized for heating the retorts. The crude oils are refined with acid and alkali, and are redistilled to furnish naphthas, burning and lubricating oils, and paraffin (q.v.). JllBLlQCiHAruY. i horpe, Uullines of Industrial Chemistry (London, 1898) ; Sadtlor, A lland- hook of Industrial Oryiinic Vhemistry (Phila- delphia, 1900) ; Allen, Commercial Oryanic Analysis (London, 1889-90) ; Brannt, .1 I'rarlical Treatise on Animal and Veyetable Fats and Oils (Philadelphia, 1890) ; Thorpe, A Dictionary of Applied Vhemislry (London, 1890-92) ; Lewko- witseh. Chemical Analysis of Fats, Oils, and ir«a;es (New York, 1898) ; Benedikt, Amdyse der Felte und ^ aehsarten (Berlin, 1892) ; Gill, Handbook of Oil Analysis (Philadelphia, 1898). OIL SAND. A term applied to beds of sand or porous .sand rock which contain petroleum. There may sometimes be several oil sands sep- arated by beds of rock in one formation. See Petroleisi. OIL SHARK, or Soup-Fin Shark. A tope- like shark of .southern California (Galrorhinus zyoplerus), often six feet long and grayish in color, with the front of both dorsal fins black. It is sought for the oil in its liver — single fishes sometimes yielding a gallon — and for the fins, which are highly prized by the Chinese as ma- terial for .soup. The fins are dried and a fine white gelatin is extracted. The fish is rarely taken except in .July and August, when it enters quiet bays to be delivered of its young. OIL-STONE. A very smooth fine-grained type of rock used for abrasive purposes, more especially for sharpening various cutting instru- ments. The material used in the manufacture of oil-stones is obtained from a number of different localities, but the most important stones at the present time are those from Arkansas, Indiana, and Germany. Those from Arkansas go imder the name of Arkansasi and ^Yashita stones and are an extremely fine-grained siliceous rock of wliite color. They are especially adapted to sharpening fine tools requiring smooth edges. Owing to the limited supply of the Arkansas rock of good quality, the ditficulty in quarrying, and the very large loss in trimming, the material retails at .$2.50 per pound. The Washita is less expensive. The flerman stone is much used for razor hones. The Indiana oil-stones, which are very fine-grained sandstones, are commonly known in the market as nindos>tan or Oninyc atones. They are not suited for sharpening such fine steel instruments as those for which Wash- ita rock is used. See Aur.vsives. OIL WELLS. See PETROLEUjr. OINTMENT (ME. oincment, from OF. oiyne- jneiil, from oiyncr, oindre. onyicr. to anoint, from Lat. unynrre, unyere, Skt. aiij, to smear). A fatty preparation, either soft or solid at ordi- nary temperatures, but liquid when rubbed itito the skin. Ointments are composed of a fatty base, either lard or vaseline, alone or mixed with olive or almnnd oils or with spermaceti or wax. to diminish or increase their consistency as de- sired. F>enzoin is often added to the lard or other base to prevent decomposition. Hydrated sheep's wool fat (lanolin) is more quickly ab- sorbed than most fats and may be mixed with more than twice its weight of water without