CAR 



CAR 



combustion was then examined, and was 

 found to be pure carbonic acid, the same 

 as that formed in the burning of charcoal; 

 but wh-*t surprised Guyton was, the quan- 

 tity produced was much greater than 

 what would have been produced by the 

 combustion of the same weight of charcoal 

 in oxygen gas : 28 parts of charcoal form 

 by combustion 100 parts of carbonic acid; 

 that is, combined with 72 of oxygen ; 

 but from only 17.8 of diamond, the same 

 quantity of carbonic acid is produced, 

 that quantity having combined with 82.1 

 of oxygen. In other words, one part of 

 charcoal combines with 2 of oxygen, 

 forming 3 of carbonic acid, while one 

 part of diamond requires 4 of oxygen, 

 and produces 5 of acid. As the term car- 

 bon in the new nomenclature is under- 

 stood to be applied to the simple base of 

 carbonic acid, it is evident that it can no 

 longer be applied to the inflammable mat- 

 ter of charcoal ; for in that matter it must 

 be combined with some other principle. 

 Guy ton supposes that this principle is oxy- 

 gen, or that that inflammable body is an 

 oxide of carbon, standing in the same re- 

 lation to carbon and carbonic acid that ni- 

 trous oxide does to 'nitrogen and nitric 

 acid. Berthollet, on the contrary, has 

 supposed that charcoal contains hydrogen 

 as a constituent part. "Whichever of 

 these opinions is adopted, the name car- 

 bon, it is obvious, must now be applied to 

 the simple base, and will therefore be the 

 chemical or systematic term appropriated 

 to the diamond. See DIAMOND. 



Besides charcoal and carbonic acid, 

 other substances have been discovered to 

 be binary compounds of carbon. The 

 one km.wn by the name of black-lead, or 

 plumbag'o, approaches nearer to the dia- 

 mond, or combines with more oxygen 

 in forming carbonic acid, than charcoal 

 does; and between charcoal and carbonic 

 acid is a gaseous compound, into the com- 

 position of which oxygen enters, though 

 it is still of the nature of an oxide. Car- 

 bon too combines with hydrogen and oxy- 

 gen, forming various elastic compounds. 

 See GAS. 



CARBONATES, in chemistry, salts 

 formed by combination of the alkalies 

 and the carbonic acid. As the acid pow- 

 ers which carbonic acid actually exerts 

 are weak, the changes which it occasions 

 in the properties of the alkalies are in 

 general inconsiderable. They retain their 

 peculiar taste and acrimony, at least to a 

 certain extent: ammonia has still its pe- 

 netrating odour, u;d in part its volatility: 

 they still, even when saturated with it, 



change the vegetable colours to a green. 

 They combine with oils, forming imper- 

 fect soaps, and the presence of the carbo- 

 nic acid scarcely opposes any obstacle to 

 the combination of their bases with the 

 other acids. 



CARBONIC add, a gaseous product of 

 the full saturation of carbon with oxygen. 

 It was made known to chemists by Dr. 

 Black, under the name of fixed air, and 

 may be regarded as the first of the aerial 

 fluids that obtained accurate examination. 

 It is composed of 75 parts of carbon, and 

 25 of oxygen. See GAS. 



CARBONIC oxide, in chemistry, a gas 

 supposed to be compounded of carbon 

 and oxygen, in the proportion of about 38 

 to 62. This gas possesses the mechanical 

 properties of air. It burns with a deep 

 blue flame, and gives out little light. See 

 GAS. 



CARBUNCE, in heraldry, a charge or 

 bearing consisting of eight radii, foul- 

 whereof make a common cross, and the 

 other four a saltier. 



CARBURET, in chemistry, a com- 

 pound substance, in which carbon is a 

 constituent part. Carburet of iron, long 

 known under the names of plumbago and 

 black-lead, is composed of 90 parts of 

 carbon and 10 of iron. It is found native, 

 is of a dark grey or blue colour, and has 

 something of a metallic lustre. It is 

 found in many parts of the world, parti- 

 cularly in Cumberland. From the sub- 

 stance obtained there the best black-lead 

 pencils are manufactured. 



CARCASE, in architecture, the shell or 

 ribs of a house, containing the partitions, 

 floors and rafters, made by carpenters ; 

 or it is the timber-work (or as it were the 

 skeleton) of a house, before it is lathed 

 and plastered : it is otherwise called the 

 framing. 



CARCASSE, or CARCUSS, in the art of 

 war, an iron-case or hollow capacity, about 

 the bigness of a bomb, of an oval figure, 

 made of ribs of iron, filled with combus- 

 tible matters, as meal-powder, salt-petre, 

 sulphur, broken glass, shavings of horns, 

 turpentine, tallow, &c. The design of it 

 is, to be thrown out of a mortar to set 

 houses on fire, and do other execution. 

 It has two or three apertures, through 

 which the fire is to blaze. 



CARCINOMA, in surgery and medi- 

 cine, a hard schirrus tumour, accompa- 

 nied with acute lancinating pains, ending 

 in ulceration. 



CARD, among artificers, an instrument 

 consisting of a block of wood, beset with 

 sharp teeth, serving to arrange the hairs 



