110 



CHARADRIIM; 



CHARCOAL 



which the last viz. o, is equal to zero, the whole ; 

 aero itself being equal to nothing. 



But besides charades of this nature there is 

 another kind rather popular at evening-parties 

 the acted charade, the character of which is entirely 

 dramatic. Half a dozen or so of the company 

 retire to a private apartment, and there agree to 

 select a certain word as the subject of the charade ; 

 let us suppose Memento. The next thing done is 

 to take the first syllable, Me, and arrange a little 

 scene and dialogue, each member taking a certain 

 part. This being accomplished, the amateur actors 

 return to the drawing-room, and commence their 

 performance, the rest of the company constituting 

 the spectators. Care is taken to mention conspicu- 

 ously, and yet not obtrusively, in the course of the 

 dialogue, the word Me, which is the subject of the 

 scene. On its conclusion, they again retire, and 

 devise a new series of incidents for the word Men, 

 and repeat the same process for the final syllable 

 To. This being also represented, they retire for a 

 fourth time to contrive the final scene, into which 

 the whole word, Memento, must be dexterously 

 introduced at an odd moment when the spec- 

 tators are thought to be off the scent. The com- 

 pany are then asked to guess the word. In order 

 to the effective performance of a charade of this 

 sort, the actors must possess a good share of inven- 

 tiveness, self-possession, and ready talk, as the 

 greater portion of the dialogue has to be extem- 

 porised. 



Charadriidae, a large family of birds, placed 

 among the so-called Grallatores, including about 

 120 species, distributed throughout the world, and 

 especially frequenting the shores of lakes and 

 rivers. They run and fly with equal success, are 

 often seen in migratory nocks, use simple excava- 

 tions for nests, and feed, often at night, on worms, 

 insects, molluscs, and amphibians. Plovers (q.v., 

 Charadrius), Oyster-catchers (Haematopus), Turn- 

 stones ( Strepsilas ), Crocodile-birds (Pluvianus), 

 and Sandpipers (^gialitis) are good examples of 

 the family. 



Charbon. See ANTHRAX. 



Charbon Roux. See CHARCOAL (WOOD). 



Charcoal is a term most frequently applied to 

 charred wood, or coal produced by charring wood. 

 Formerly, charcoal was the name for charred sea- 

 coal or mineral coal ; and the word is popularly 

 used for the carbonaceous residue of vegetable, 

 animal, or mineral substances when they have 

 undergone smothered combustion. 



ANIMAL CHARCOAL, BONE-BLACK, or IVORY- 

 BLACK, is prepared from bones by heating them in 

 close retorts till they undergo the process of 

 destructive distillation, when combustible gases 

 and water, together with the vapours of various 

 salts of ammonia, and oil, are given off, and bone- 

 black is left in the retort. It is generally reduced 

 to coarse grains from about the size of small peas 

 down to large pin-heads, and is extensively used in 

 the arts for decolourising liquids, such as the syrup 

 of sugar, and solutions of argol (impure cream of 

 tartar) and of the alkaloids, as also in filters (see 

 FILTER) for separating chemical impurities from 

 water. The general mode of using the bone-black 

 is to allow the coloured liquid to percolate through 

 a layer of the charcoal, when all colour is arrested, 

 and the syrup or water runs clear and colourless 

 from under the stratum of charcoal. This power 

 of absorbing colouring matters is also observable in 

 vegetable ( peat or wood ) charcoal, but not to such 

 an extent as in bone-black. The application of 

 heat to the liquids before filtration greatly facili- 

 tates the decolourisation, and where the volume of 

 liquid to be operated upon is not great, the most 

 expeditious method is to boil the liquid and bone- 



black together, and then strain through filtering- 

 paper or cloth. The composition of bone-black in 

 100 parts is 10 of pure charcoal, associated with 90 

 of earthy salts i.e. in the proportion of one of 

 pure charcoal in 10 of the commercial bone-black. 

 The power of absorbing colours appears to be due 

 to the porosity of the substance, and is not resident 

 simply in the pure charcoal ; indeed, the earthy 

 matters ( principally phosphate of lime and carbon- 

 ate of lime ) can be dissolved out of the bone-black 

 by dilute hydrochloric acid, and the pure charcoal 

 thus obtained only possesses about one-third the 

 decolourising power of the total amount of bone- 

 black it was obtained from. Thus, if 100 parts of 

 ordinaiy bone-black have the power of arresting 

 the colour from ten volumes of a given coloured 

 liquid, then the 10 parts of pure charcoal which can 

 be obtained from the 100 parts of bone-black will 

 be found to decolourise only three volumes of the 

 same coloured liquid ; so that it is apparent the- 

 earthy matters in the bone-black influence and 

 increase the absorption of the colouring matter, 

 and thus render a given weight of the charcoal of 

 greater commercial value. When syrup of sugar 

 and other liquids have been run through bone- 

 black for some time, the pores of the latter appear 

 to get clogged with the colour, and the clarifying 

 influence ceases, and then the bone-black require* 

 to undergo the process of revivification, which con- 

 sists in reheating it carefully in ovens, or iron pipes 

 inclosed in a furnace, when the absorbed colour is 

 charred, and the bone-black can be of service once 

 again as an arrester of colour. After several re- 

 burnings, the bone-black becomes of very inferior 

 absorptive quality, and is then disposed of for the 

 manufacture of bone-ash and dissolved bones (see 

 BONE MANURES). Bone-black has likewise a great 

 power of absorbing odours, especially those of a 

 disagreeable nature, and can thus be employed 

 to deodorise apartments, clothing, outhouses, &c., 

 or wherever animal matter may be passing into a 

 state of active putrefaction. 



WOOD CHARCOAL is the most important, though 

 not the purest kind of Carbon (q.v.). Wood con- 

 sists of carbon, hydrogen, and oxygen, the last 

 two being in the proportion to form water. When 

 heated in the open air, it burns completely away, 

 with the exception of a small white ash ; but if the 

 supply of air be limited, only the more volatile 

 matters burn away, and most of the carbon remains. 

 This is the principle of the process of charcoal- 

 burning in countries where wood is abundant. 

 Billets of wood are built up vertically in two or 

 three rows into a large conical heap, which is 

 covered over with turf or moistened charcoal - 

 ash, and holes left at the bottom for the air to 

 get in. An open space is also left in the middle 

 of the heap to serve as a flue. The heap is set 

 on fire by putting burning wood into the top 

 of the central opening. The combustion pro- 

 ceeds gradually from the top to the bottom, and 

 from the centre to the outside of the heap ; and 

 as the central portions burn away, fresh wood 

 is continually thrown in at the top, so as to 

 keep the heap quite full. The smoke is thick and 

 white when the process is going on properly ; if it 

 becomes thin, and especially if a blue flame ap- 

 pears, the wood is burning away too fast, and the 

 combustion must be checked by closing the holes 

 at the bottom, or by heaping fresh ashes on the 

 top and sides. As soon as the combustion is com- 

 pleted, the heap is completely covered with turf or 

 ashes, and left to cool for two or three days. It is 

 then taken to pieces, and the portions still hot are 

 cooled by throwing water or sand upon them. It 

 is found that 100 parts of wood yield on the average 

 from 61 to 65 parts by measure, or 24 parts by 

 weight, of charcoal. The charcoal thus prepared 



