CARBON. 



to lodge there ; because they are of opi- 

 nion, that a man that has no wife is more 

 dangerous than another. 



CARBON, in chemistry. The term car- 

 bon having been understood in different 

 senses, and having been actually applied 

 to different substances, it is necessary to 

 guard against the ambiguity arising from 

 this circumstance, and with this view to 

 trace in a general manner the progress of 

 those discoveries, from which the name 

 originated, and by which its application 

 has since been changed. 



When vegetable matter, especially the 

 more solid parts of plants, the wood for 

 example, is exposed to heat in close ves- 

 sels, it is decomposed ; the more volatile 

 principles are disengaged, and there re- 

 mains a black, shining, porous body, com- 

 posed of the various substances which are 

 not convertible by a high temperature to 

 the gaseous form. This substance is 

 termed charcoal. While the atmospheric 

 air is excluded, it is neither fused nor 

 volatilised by any increase of heat ; but 

 when the air is admitted, it suffers 

 combustion, and it continues to burn 

 till nearly the whole of it is consumed ; 

 the residuum amounting to not more than 

 the 200th part of the weight of the 

 original charcoal. This residuum is un- 

 inflammable, and consists principally of 

 saline and metallic matter. Charcoal 

 then is a heterogeneous substance. By 

 far the greater part of it consists of an 

 inflammable substance, which combines 

 with oxygen, and forms the carbonic acid 

 of the modern nomenclature. But this in- 

 flammable matter, as it exists in the char- 

 coal, is mixed or combined with the 

 saline and metallic substances left after 

 its combustion. For the sake of pre- 

 cision, a distinction is made in the new 

 nomenclature, between the pure inflam- 

 mable base and the substance in which 

 it is thus presented to us. Charcoal is 

 that black porous substance obtained 

 from vegetable matter, especially from 

 wood, by exposing it to heat ; and the 

 pure inflammable substance, which com- 

 poses by far the greater part of the char- 

 coal, was termed carbon. Carbon, there- 

 fore, according to this signification, was 

 charcoal destitute of the small quantity of 

 saline and metallic matter usually mixed 

 with it. The principal advantage of the 

 introduction of the name carbon was, not 

 merely that of distinguishing the inflam- 

 mable base from the substance in which 

 it was mixed with other ingredients, but 

 also that of giving a term capable of com- 

 bination, and of affording those deriva- 



tive appellations which the modern sys- 

 tem requires. This substance is not a hy- 

 pothetical being, since, by certain chemi- 

 cal processes, by the decomposition of 

 carbonic acid for instance, or of alcohol 

 by heat, it is possible to obtain it perfect- 

 ly pure. It exists in a large quantity as 

 a component part of vegetable sub- 

 stances ; it enters into the composition of 

 animal matter, and is contained in sub- 

 stances belonging to the mineral king- 

 dom. This substance, which, when it is 

 obtained pure, exists in the form of a ve- 

 ry light black powder, was, until within 

 these few years, considered as a simple 

 body; but experiments have proved, 

 that it is a compound, containing an in- 

 flammable substance, according to some 

 chemists, in a state of imperfect oxyda- 

 tion ; according to others, combined with 

 hydrogen. It had been known for a con- 

 siderable time, that the diamond, the 

 most beautiful and most unchangeable of 

 the productions of nature, is combustible, 

 or that when heated vsith oxygen gas it 

 suffers combustion. Lavoisier made some 

 experiments to ascertain the nature of 

 the product of this combustion; and he 

 found it to be an acid precisely the same 

 with that which is produced by the burn- 

 ing of charcoal what is termed the car- 

 bonic acid. He did not, however, as- 

 certain the proportion of it with suffi- 

 cient accuracy to draw any precise conclu- 

 sion. Some time after, Mr. Tennant re- 

 peated the experiment of oxydizing the 

 diamond, by exposing it to heat along 

 with nitrate of potash in a gold tube. 

 He also found that carbonic acid was 

 formed; and from an experiment on a 

 small scale, it appeared that about the 

 same quantity of carbonic acid was af- 

 forded by the oxygenation of the diamond, 

 as would have been produced by the 

 combustion of the same weight of char- 

 coal. He concluded that the diamond was 

 carbon, and differed from charcoal prin- 

 cipally in its form and state of aggrega- 

 tion ; that, in short, it might be consider- 

 ed as carbon crystallized. 



At length Guyton resolved to examine 

 this subject, and his experiments afforded 

 very important results. The diamond on 

 which he experimented was burnt in a 

 vessel of oxygen gas, by directing the so- 

 lar rays upon it through a very powerful 

 lens. It assumed at first a leaden colour ; 

 by the farther continuance of the heat its 

 surface appeared charred. At length it 

 appeared sensibly to diminish, and in lit- 

 tle more than an hour and a half was en- 

 tirely consumed. The product of the 



