Page:The American Cyclopædia (1879) Volume II.djvu/566

 646 BENZOLE yields 80 per cent, of resin, or 20 per cent, of benzole acid. BENZOLE, a peculiar product of coal tar, im- portant in the manufacture of aniline colors. (See BENZINE.) Its chemical formula is0 12 H 6 (old), or C 6 II S (new). Its synonymes are henzol, benzin, benzene, bicarburetted hydro- gen, and hydrite of phenyl (Fr. phene). There are numerous methods for the preparation of benzole, but the only one of practical value, invented by Mansfield in 1847, is founded upon the distillation of coal tar. The crude tar, as it comes from the gas works, is first subjected to regulated distillation, so as to obtain sep- arately naphtha or light oil (oily liquid lighter than water); secondly, after all the naphtha has passed, dead oil or heavy oil (oily liquid sinking in water); and thirdly, pitch, which remains behind in the retort. From the light oil the benzole is separated by further frac- tional distillation. The resulting product, which is fur from being absolutely pure, is the well known preparation for removing grease stains from articles of dress. It is also extensively used as a solvent of caoutchouc and resins. When required for the production of aniline, it must be rectified by subjecting it to further operations. The boiling point of pure benzole is 80 0. (176 F.), whereas commercial benzole boils from 80 to 120 0., and is therefore a mixture of several compounds. The transfor- mation of benzole into nitro-benzole is accom- plished by dissolving benzole in fuming nitric acid and mixing the clear liquid with water, when the nitro-benzole is precipitated as a dense yellow liquid. Nitro-benzole has for some years been sold under the trade name of essence de mirbane, or artificial oil of bitter al- monds. Nitro-benzole when submitted to the action of reducing agents is converted into aniline. The successive changes of benzole are thus expressed in chemical symbols : First change, transformation of benzole into nitro-benzole : C,H, + 4NO S = C,H 6 NO, + H,O. Benzole. Nitric acid. Nitro-benzole. Water. Second change, transformation of nttro-benzolo Into aniline: CjH.NO., + 811,8 = C,H,N + 2H,,O + 89. Nitro-benzole. Sulphuretted Aniline. Water. Sulphur, hydrogen. On the large scale, instead of sulphuretted hy- drogen, nascent hydrogen produced from iron turnings and acetic acid is employed as the re- ducing agent. The inhalation of nitro-benzole produces insensibility to pain, but from some slight irritation it was found to occasion when the experiments were made, it has not come into general use as an anaesthetic. At ordinary temperatures benzole is a limpid, colorless, strongly refracting oil, of specific gravity 0'85 at 15-5 C. When cooled to +3 0. it solidi- fies into fern -like tufts or into masses like cam- phor, which melt at 5-5 C., expanding one eighth of their volume, and freezing again at 0. Prof. Hoffmann takes advantage of the freezing of benzole to obtain it pure. For this purpose the impure article is placed hi a tin or BERANGEK brass vessel, in which an iron rod, having at- tached a close-fitting piston perforated with numerous small holes, is made to play. On forcing down the plunger the liquid portions ascend and can be drawn off, and on melting the frozen benzole it will be found to be near- ly pure. Cooled to 18 C., benzole becomes so hard and brittle that it can be pulverized in a mortar. It boils at 80 C., and volatilizes undecomposed. The oil has a pleasant ethereal smell, and when breathed produces insensi- bility attended by convulsions; internally it acts as a violent poison. The density of its va- por is 2'75 (calculated 2'704). It is not soluble in water, although it imparts a color and odor to that liquid. Alcohol, wood spirit, acetone, and ether are good solvents of benzole. It dis- solves fats, the fixed and essential oils, cam- phor, wax, india rubber, gutta percha, resins, asphaltum, sulphur, phosphorus, iodine, and picric acid; gum lac, copal, anim, and gam- boge in small quantity; quinine, somewhat readily ; strychnine and morphine in small quantity ; cinchonine, not at all. It is inflam- mable, and burns with a bright smoky flame ; and when its vapor is added to illuminating gas, it materially contributes to the illuminating power; hence it finds extensive application in carburetting or carbonizing poor gas, and in the manufacture of "air gas." The namephene was proposed for it by Laurent in allusion to its high value as an illuminating agent, from ^eiveiv, to emit light. It is now nearly super- seded for this purpose by petroleum benzine, on account of the comparatively great expense of benzole. A mixture of one volume of ben- zole with two volumes of alcohol forms a very good lamp oil; more benzole gives rise to a smoky flame. When benzole is passed through a red-hot tube, it is decomposed into solid carbon and a gaseous hydrocarbon. Under favorable circumstances 100 Ibs. of coal will yield lOf Ibs. tar, 8 oz. tar naphtha, 3 oz. ben- zole, 4 oz. nitro-benzole, and 2 oz. aniline. Benzole has been found ready formed in the native petroleum of Rangoon, and has been made synthetically by Prof. Schulze by the direct oxidation of carbon by means of per- manganate of potash. As benzole acid, from which benzole was originally distilled by Mit- scherlich, has also been made artificially, it is not impossible that a synthetical method for the manufacture of benzole may eventually be discovered. BEOWl'LF, Tale of. See ANGLO-SAXONS, LAN- GUAGE AND LITERATURE OF THE, vol. i., p. 504. BERANGER, Pierre Jean de, a French lyric poet, born in Paris, Aug. 19, 1780, died there, July 16, 1857. His father was bookkeeper to a grocer, and married a milliner, the daughter of a tailor of the name of Champy, who kept a small shop in the rue Montorgueil. Here the future bard came into the world, which fact he commemorated in one of his most sprightly songs, Le tailleur et la fee. He sprang thus from the people, and in spite of the particle de,