Page:Encyclopædia Britannica, Ninth Edition, v. 5.djvu/410

398 misunderstanding between him and Napoleon occasioned Chaptal s retirement from office in 1804; but before the end of that year he was again received into favour by the emperor, who bestowed on him the grand cross of the legion of honour, and made him treasurer to the conserva tive senate. On Napoleon s return from Elba, Chaptal was made director-general of commerce and manufactures and a minister of state. He was obliged after the downfall of the emperor to withdraw into private life ; and his name was for a time removed from the list of the peers of France. In 1816, however, he was nominated a member of the Academy of Sciences by Louis XVIII. Notwith standing the many vicissitudes of fortune which he under went, Chaptal continued to promote the interests of science until his death, which took place at Paris, 30th July 1832.

1em  CHAPTER, the community of men connected with a or. See.  CHAPU, an important of, in the  of, 50 s N.W. of , situated in one of the richest and best  districts in the country. It is the of, with which it has good  , and it was formerly the only    with. The has a  of about five s, exclusive of the s that lie along the ; and the  quarter is separated from the rest by a. It was attacked and much injured by the , but was abandoned immediately after the engagement.  CHARADE, a trifling species of, or quasi- form of, which may perhaps be best defined as a ning enigma propounded in a series of descriptions. A is taken of two or more s, each forming a distinct ; each of these is described in or, as aptly and enigmatically as possible; and the same process is applied to the whole. The neater and briefer the descriptive parts of the problem, the better the charade will be. In selecting s for charades, special attention should be paid to the absolute quality of the s composing them, inaccuracy in trifles of this sort depriving them of what little claim to merit they may possess. The brilliant rhythmic trifles of are well known. Of representative prose charades, the following specimens are perhaps as good as could be selected:—&ldquo;My first, with the most rooted antipathy to a, prides himself, whenever they meet, upon sticking close to his jacket; my second has many s, nor is its least that it gives its to my first; my whole may I never catch!&rdquo; &ldquo;My first is ; my second shuns ; my third collects ; and my whole amuses .&rdquo; The solutions are Tar-tar and Co-nun-drum. &ldquo;Acting charades&rdquo; are simply ning enigmas described tically. A brilliant description of this variety of the species will be found in 's Vanity Fair.  CHARCAS. See.  CHARCOAL, the more or less impure form of carbon obtained from various vegetable and animal materials by their ignition out of contact with air.

Wood Charcoal is a hard and brittle black substance, that retains the form and external structure of the wood from which it is made. It rings when struck, and has a conchoidal fracture ; it is infusible, and is not dissolved by water or acids ; at ordinary temperatures it is a bad con ductor of heat and electricity. Charcoal varies much in degree of compactness, box-wood giving a very solid, and willow a porous variety. Exclusive of its pores, it has a specific gravity of 1*5, or, if made at a high temperature, of 2 0. Charcoal from Scotch fir weighs from 10 3 to 10 - 9 lb per cubic foot; that made from oak is heavier. Very light charcoal is prepared from dogwood, alderwood, and willow. Charcoal contains, besides carbon, varying (but small) quantities of hydrogen, oxygen, and nitrogen ; and when consumed, it yields from 1 to 5 per cent, of ash, or the greater part of the mineral matter contained in the original wood. Charcoal burns without flame, and has in air a calorific intensity of about 2700 C. ; its specific heat, according to Regnault, is 2411. The higher the temper ature to which it has been exposed, the higher is the igniting point of charcoal; and that made at the melting point of platinum requires a temperature of 1250 C. to kindle it. Fresh-burnt charcoal rapidly absorbs from 9 6 to 18 per cent, of its weight of atmospheric moisture, of which the commercial article usually contains about 12 percent. It has also a remarkable absorptive action on gases, condensing them within its pores. To the heat thus developed has been attributed the occasional spontaneous ignition of char coal that has been stacked too soon after manufacture. Recently-made box -wood charcoal absorbs, at 12 C. and 28 &quot;5 in. pressure, 90 volumes of ammonia, 85 of hydro chloric acid, 05 of sulphurous anhydride, 55 of sulphuretted hydrogen, 35 of carbonic anhydride, 9/ of oxygen, and 6^ of nitrogen ; only 1^ vols., however, of hydrogen (Saussure). The absorptive power for gases is nearly in the ratio of the pressures to which the charcoal is exposed, the temperature being constant. Charcoal can be made at a temperature as low as 300 C. It is produced in greatest quantity at a heat just sufficient thoroughly to char the wood. The charcoal so made con tains a larger percentage of hydrogen, oxygen, and nitrogen than that formed at higher temperatures, and, being readily inflammable, is adapted for the manufacture of gunpowder. The quantity of charcoal obtainable from wood varies according to the nature of the wood employed and the method of manufacture. By distillation 25 to 27 per cent, of the weight of the wood can be obtained. Ordi narily, beech yields about 15 per cent, of its yeight, box 20J per cent. Mr Mushet obtained in his experiments the following percentage composition of various kinds of wood, the amount of each kind taken being 1 lb avoirdupois:—

Vo iatile Matter. Charcoal, Ashes. Oak 76-895 22-682 0-423 Ash. 81-260 17-972 0-768 Birch ....:.... 80717 17-491 1-792 Norway Pine 80-441 19-204 0-355 Mahogany 73-528 25-492 0-980 Sycamore 79-20 19-734 1-066 Holly 78-92 19-918 1-162 Scotch Pine 83-095 16-456 0-449 Beech 79-104 19-941 0-955 Elm 79-655 19-574 761 78-521 20-663 0-816 American Maple 79-331 19-901 0-768 American Black Beech Laburnum 77-512 74-234 21-445 24-586 1-033 1-180 Li fr num Vitce 72-643 26-857 0-500 Sallow 80-371 18-497 1-132 76 304 23 280 0-416

