CHARCOAL 



< H A RENTON-LE-PONT 111 



is i In- be -i suited for fuel. In England a large 

 quantity c,i charcoal, is obtaine<l in the dry dis- 

 tillatirtn of wood in east-iron cylinders, for the pre- 



linii <if crude acetic acid. The charcoal thus 

 prepared is preferable for making gunpowder, but 

 i- inferior for other purposes. A peculiar kind of 

 charcoal of a reddish -brown colour, and hence 



nod charbon rum- or red clitin-oal, is frequently 

 prepared for the manufacture of the gunpowder 

 u-.'d for sporting purposes, by subjecting wood in 

 iron cylinders to the action of superheated steam 

 under a pressure of two atmospheres. Powder 

 made \\itii tliis charcoal absorbs moisture more 

 rapidly than ordinary gunpowder. 



The general properties of wood-charcoal are, that 

 ii is black and orittle, and retains the form of the 



I from which it is derived ; it is insoluble in 

 i , infusible and non-volatile in the most in- 

 tense heat; its power of condensing gases is 

 noticed under Carbon (q.v.) ; and from its power of 

 destroying bat! smells it has been regarded as 

 possessing considerable antiseptic properties. It is 

 frequently stated that charcoal is a bad conductor 

 f heat, but a good conductor of electricity. These 

 properties depend upon the nature of the charcoal, 

 the lighter wood, such as willow, yielding a porous 

 charcoal, with little power of conducting heat or 

 electricity ; while boxwood yields a very compact 

 charcoal, which is a good conductor of heat and 

 electricity, and is admirably adapted for the exhi- 

 bition of the electric light. Charcoal never consists 

 entirely of pure carbon, the degree of purity vary- 

 ing directly with the temperature at which, it is 

 formed ; thus, charcoal charred at 480 (249 C.) 

 contains 65 per cent, of carbon, while that charred 

 at 750 (399 C.) contains 80, and that charred at 

 2730 (1499 C.) contains 96; but the loss of char- 

 coal occasioned by these high temperatures is very 

 great, the percentage yield of charcoal correspond- 

 ing to these temperatures being 50, 20, and 15. 



The uses of wood-charcoal are numerous and 

 extensive. It is very largely employed as a fuel, 

 taking the same place in many countries that coal 

 occupies here. From its being proof against all 

 ordinary chemical agencies, superficial charring is 

 often employed to protect wood from decay, as in 

 tin- case of fence-posts, of telegraph poles, or of 

 piles which are driven into mud or into the beds of 

 rivers to serve as foundations. With the same 

 de>ign it is not unusual to char the interior of tubs 

 and casks destined to hold liquids. In a finely- 

 divided state it is commonly regarded, as has been 

 already stated, as an antiseptic ; and there is no 

 doubt that the offensive effluvia from animal 

 matter in an advanced stage of putrefaction dis- 

 appear when the putrefying substance is covered 

 with a layer of charcoal; but in reality the decay 

 goes on, without the emission of any odour, till at 

 length the whole of the carbon is dissipated as 

 carbonic acid gas, and the hydrogen as water, 

 while the nitrogen remains as nitric acid. It 

 lias been shown that the action consists in a rapid 

 process of oxidation, dependent upon the jiower 

 which finely-divided charcoal possesses of condens- 

 ing oxygen. In a finely-divided state, charcoal not 

 only condenses gases to a marvellous extent, hut 

 has the power of absorbing colouring matters, bitter 

 principles, &c. ; and hence it is of extensive use in 

 the laboratory. From the rapidity of its absorbing 

 action, the use of a respirator filled with charcoal 

 has been suggested to protect the mouth and 

 nostrils in an infected atmosphere; trays of pow- 

 dered wood-charcoal in dissecting-rooms, in the 

 wards of hospitals, and in situations where putres- 

 I'ent animal matter is present, exert a most bene- 

 ficial influence in sweetening the atmosphere, by 

 absorbing and decomposing the offensive gases. 

 Charcoal is accordingly valuable in filters, not only 



for decolourising purpose*, but likewise for a*M*t- 

 ing in purifying water for domestic uue. It in alxo 

 successfully used to prevent the encape of noxiouM 

 vapours at the ventilating openings of newer*, 

 as it allows the free passage of air, but condense* 

 the offensive effluvia in it* |oreH, where they are 

 destroyed by a process of oxidation. Benide* it* 

 employment in tne manufacture of gunpowder it 

 has many applications in the arts. In medicine it 

 IB used to destroy fetor, applied in the form of 

 powder or poultice to gangrenous sores, ulcers, 

 c. ; it is also largely employed in tooth-powder*. 

 In indigestion accompanied by flatulence it may 

 be given in doses of two or three teaspoonfufs 

 suspended in water, or as charcoal-biscuits (gee 

 BISCUITS ). For the charcoal blacks, see BLACK. 



Charcot, JEAN MARTIN ( 1825-93), pathologist, 

 was born at Morvan (in Nievre), studied at Paris, 

 where he became a professor, doctor at the Sal- 

 pfitriere hospital, and a member of the Institute. 

 He contributed much to our knowledge of chronic 

 and nervous diseases, their diagnosis and pathology, 

 and made hypnotism a scientific study. He pub- 

 lished numerous works on these subjects. 



Cliard, a municipal borough of Somersetshire, 

 15 miles SSE. of Taunton by rail, with manufac- 

 tures of lace. Pop. 2575. 



< hard in. SIR JOHN (1643-1713), traveller, was 

 born in Paris, travelled as a trader in jewels in 

 India, Persia (where he resided four years), Ar- 

 menia, Turkey, and published his Voyages (4 vols.) 

 in 1686-1711. To escape the persecution of Protes- 

 tants, he settled in England in 1681, became court- 

 jeweller, was knighted, and for some years lived in 

 Holland as agent of the East India Company. 



Charente, a department of France, formed 

 chiefly out 01 the old province of Angoumois. 

 Area, 2285 sq. m. Pop. (1866) 378,218; (1891) 

 360,259. It is generally level, with granite off- 

 shoots of the Limousin range in the north, and 

 chalk-hills in the south, abounding in marine de- 

 posits ; and it is watered by the river Charente and 

 its tributaries, with the rivers Vienne and Dronne. 

 The hills are in many places clad with chestnut 

 forests. The climate is generally mild and healthy, 

 and a sixth of the surface is devoted to vines, which 

 flourish in the dry 7 , hot limestone soil. The wines 

 grown are spirituous and fiery in flavour, and 

 are chiefly distilled into brandy, which forms the 

 most important of the exports. Truffles grow 

 abundantly in several parts. The principal manu- 

 factures besides brandy are paper, leather, felt, 

 and pottery. Charente is divided into the five 

 arrondissements of Angouleme, Cognac, Ruflec, 

 Barbezieux, and Confolens. Angonleme is the 

 chief town. 



Charente-Infe'rieiire, a maritime depart- 

 ment of France, formed principally from the former 

 provinces of Saintonge, Aunis, and a small portion 

 of Poitou. The Bay of Biscay washes its western 

 boundary. Area, 2625 sq. in. "Pop. ( 1866) 479,529; 

 (1891 ) 456,202. It is watered on its boundaries by 

 the Sevre-Niortaise and the Gironde, and in the 

 centre by the navigable Charente and the coast- 

 stream Seudre. The surface is level ; the soil, near 

 the coast protected from the sea by dikes, is mostly 

 chalky and sandy, but very fertile. The commerce 

 is mainly in brandy and sea-salt ; the evaporation 

 from the salt-marshes from which the latter is 

 taken renders some parts of the coast very un- 

 healthy. The oyster and pilchard fisheries are 

 important. The chief harbours are those of Roche- 

 fort and Tonnay-Charente. La Rochelle is the 

 chief town. 



Charenton-le-Pont* a town in the French 

 department of Seine, on the right bank of the 



