The principles of chemistry : illustrated by simple experiments / by Julius Adolph Stöckhardt ; translated form the 5th German edition by C.H. Peirce.

  • Stöckhardt, Julius Adolph, 1809-1866.
Date:
1851
Catalogue details

Licence: Public Domain Mark

Credit: The principles of chemistry : illustrated by simple experiments / by Julius Adolph Stöckhardt ; translated form the 5th German edition by C.H. Peirce. Source: Wellcome Collection.

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    case, the heat was not sufficiently strong entirely to consume the wood; in the second, the complete burn¬ ing was prevented by quenching, and in the third by the exclusion of air. All animal and vegetable substan¬ ces, if only partially burnt, are converted into coal. As coal, on exclusion of the air, cannot be melted, even in the strongest heat, so the exterior of it is very different, according to the character and structure of the sub¬ stance from which it was prepared; indeed, this differ¬ ence often extends itself throughout the interior struc¬ ture, as in charcoal, soot, coke, bone-black, &c. In the charring of organic bodies the coal is not generated, but it previously existed in them, though in chemical combi¬ nation with other substances, which are principally driv¬ en off by heat, as is obviously the case from the fact that the charred body weighs much less than the orig¬ inal substance. All animals and plants consist, there¬ fore, partly of coal; or, in chemical language, of Car¬ bon = C. Carbon also exists in the mineral kingdom. It forms the principal element of pit coal, brown coal, &c., which have all been formed from the vegetation of an earlier period. It is found almost pure in the diamond and in the graphite, and, combined with oxygen, is con¬ tained in limestone, marble, chalk, and various other minerals. 104. Charcoal (C containing a little ashes.) Experiment. — Gradually intro¬ duce a burning splinter of wood into a test-tube. The part out¬ side of the tube only will burn with a flame, while that within merely chars, because the air is Fig. 65.