Page:The New International Encyclopædia 1st ed. v. 04.djvu/578

CHAKEON. 498 CHARDIN. CHAKBON, -h-ii'lioii. Sec Anthrax. CHARBON ROUGE, sliiii'box' iwzli' (Fr.), or Rkd Chabcoal. A variety of oliarooal ob- tained by subjeoting ivood to the action of heat- ed air from furnaces, or of steam, whidi lias been raised to a temperature of 572° F. Air-dried wood, by the ordinaiy process of charrinfr. yields at the best 21 to 2(i per cent, of black charcoal; but when acted on by heated air or steam, as mentioned above. :W or 42 ]wv cent, of cbarbon rouge is obtained. It is used in the manufacluro of gunpowder. It has a dark-red color, and con- sists of about 75 per cent, pure carbon and 25 per Cent, hydrogen and oxygen. CHAR'CAS. See CuUQriSACA. CHARCOAL (probably from >IE. charken, to crackle. AS. ceorcian, to creak, variant of cracioJi, to crack + cole, coal : less plausibly from char, turn, from AS. ccrr, Ger. Kdir. turn + cole, coal). A black, porous substance burning with- out smoke or flame, and fonned by the imperfect combustion of organic matter, either animal or vegetable. Aninml charcoal is produce<l by cal- cining the bones and ivory of animals in closed retorts. In this jirocess the charcoal proper, which consists of the earthy and saline porticms of the bone, combined with carbon, is left in the retort, while the volatile matter is allowed to escajie into another compartment, whei-e it is distilled. The escaping gas contains, among its other components, an oil which, when burned in closed chaml)ers. deposits a soot which is known as hoiie-hlacl; or irorii-hlncl: pigment. (See Lampulack.) .Vninial charcoal, or bone- black, is itself a most useful material in the art-s, on account of its power of absorbing color- ing matter and odors. It is the best material known for filtering saccharine solutions (see Sugar), and various processes have been invent- ed for recalcining bone-black after it has been used until no longer efl'ective. Wood-charcoal may be produced either in temporal^ furnaces formed by simply covering piles of wood with earth or sand, (U" in permanent furnaces specially designed for the purpose. If the former method is employed the wood is fired usually at the top, a central space being left from bottom to top for the progress of the fire. The gases are allowed to escape through holes left in the top. Tliis method is nuich less fre- quently employed than formerly, as it not only produces an inferior grade of charcoal for manu- facturing purposes, though not for fuel, but also inv(dves the loss of the by-products, which escape in the gases and are lost. A charcoal- furnace is usually a dome-shajicd structure with openings at the top and side for putting in the wood and a pipe or tube near the top for the escape of the volatile products. The wood rests on grates, and the qiiantity of air is regulated by a closely fitting ash-pit door. The wood is fired at the bottom, and when the process of com- bustion has snUicicntly advanced, the ash-pit door is closed. The wood is now slowly car- bonized, and the gaseous jiroducts escape into another chamber, where they are treated as de- scribed tinder Lampisi.ack. Wood-charcoal has many uses. It is valuable as a fuel, a polish, a filter, an absorbent of gases and aqueous vapors. As it is a non- conductor of heat, it is tised as a packing for ice- chests; it is essential in various kinds of elec- trical a])paratus. and is an ingredient in gun- ]>ow(ler an<l fireworks. CHARCOAL BLACKS. Pigments prepared both from animal and vegetable substances — e.g. burnt ivory, bones, vine-twigs, peach-stones, nut uMil other sliells, the smoke of resin condensed, etc. See C'llAKco.L. CHARCOT, shar'kA', .Teax Martin (1825-93). .V French neurologist, born in Paris. He re- ceived his .Icgree of M.D. in ISo.'?, and in 1S56 was appointed physician to the Central P.nreau of Hospitals. In lS7.'i he was elected a member of the Academy of ^Medicine, in the secticm of I)athological anatomy, and in the same year be- came professor of pathological anatomy in the Faculty of Medicine in Paris, a position which he exchanged in 1882 for the professorship of dis- eases of the nervous system. He was widely known through his lectures delivered at the SaiJl(■■tri^l■e Ilospitiil. His various works are entitled : De I'cJrpcctation en mcdecinc (1857); Dc la /oifK- monie chroniqie (I8G0) ; La mddecine empiriqite ct la medecine scicntifique (1867); Lemons cli- nifjues sur les maladies des vicillards (18(58); Lemons sur les maladies du syst^me nervcux (187."?); LcQons sur les maladies du foie, des voies biliaires et des reins (1877) ; Localisations dans les maladies du cerrcau et de la nioclle cpiniere (1870-80) ; Lecons sur les maladies <lu si/slcme nerveux faiies a la Salpctricre (1880). C liarcot also annotated the French translation of Baring Garrod's Treatise on (lout. He wa-s one of the editors of the Archives de phiisiolofiie. His extensive researches on the value of hypnotic sug- gestion, in the treatment of hysteria and other morbid conditions, formed important contribu- tions to our knowledge of nervous iliseases and their therapeutics, and won for Charcot a wide reputation among the lait,v as well as in the medical world. CHARD, Swiss Chard, or Sea-Kaijc. A form of the common garden beet (q.v. ), in which the edible portion is the enlarged (Icshy stalk and midrib of the leaves. Unlike garden beets, the roots are small and wood.v. Chard is used as a pot vegetable for greens and salad. It is grown, in the same manner as garden licets, by planting in early siiring in rows 10 to 20 inches apart, and thinning to stand 14 to l(i inches distant in the row. The stalks and leaves are read.v for use toward the close of summer. CHARDIN, sluir'drix'. Jean- (Sir ,Joitn) (104.3- 1713). .V Freiich-Fnglish traveler, born in Paris. In 1004-00, and again in 1071-75, he made exten- sive journevs to Persia and India, where he had manv .adventures and acquired much wealth by trade in jewels. Bc-ause of the persecution of the Protestants in France, he settled in London in IGSl, was knighted b.v Charles II., and was often referred to as 'the flower of merchants.' He was for some years Englisli Fnvoy to the Xetherlands, and devoted his later years to Ori- ental studies. In 1080 he published a portion of the Traoels of Sir John Chardin into Persia and the East Indies. A reprint of the French edition of the complete work ajipcared in Paris in 1811. He gives a graphic and faithful account of wh.at ho saw and heard, and the part dealing with Persia, at whose cajiital he lived for many jears, is of especial value.