The elements of materia medica and therapeutics: 5. Carbonium. - Carbon.

The elements of materia medica and therapeutics
by Jonathan Pereira, M.D. F.R.S. & L.S.
Fourth Edition, enlarged and improved, including notices of themost of the medicinal substances in use in the civilized world, and forming an Encyclopædia of Materia Medica.
Vol. I.
London: printed for Longman, Brown, Green, and Longmans, Paternoster Row.


1 [There ia a considerable difference of opinion among chemists respecting the equivalent number and volume of carbon vapour. In a work specially devoted to Materia Medica we have not thought it advisable to make any change. — Ed.]

2 Edinb. Philosophical Journal, vol. iii. p. 98; and Philosophical Magazine, vol. i. p. 147, 1827.

3 Geological Transactions, 2d series, i. 419.

4 De la Beche, Researches in Theoretical Geology, p. 32, London, 1834.
Symbol C. Equivalent Weight 6.1 Equivalent Volume of Carbon Vapour (P) 1 or []

History. — The term carbon (from carbo, õnis, coal) was first employed by Morveau, Lavoisier, and Berthollet, to designate the pure matter of charcoal. To the second of these chemists we are indebted for demonstrating, that by combustion in oxygen gas the diamond and charcoal yield the same product — namely, carbonic acid gas.

Natural History. — Carbon is found in both kingdoms of nature:

a. In The Inorganised Kingdom. — When pure and crystallised, it constitutes the diamond, which Sir D. Brewster2 suspects to oe of vegetable origin; but a specimen, described by Mr. Heuland,3 was found in a primary rock. Plumbago and anthracite consist principally of carbon. The bituminous substances (as coal, petroleum, naphtha, &c.) also contain it. These are admitted by geologists to be of vegetable origin. Carburetted hydrogen is evolved from coal strata, marshy places, stagnant waters, &c. Carbonic acid is found either in the free state, as in the atmosphere, in mineral waters evolved from the earth in old volcanic countries, &c, or combined with metallic oxides, in the form of the carbonate of lime, iron, &c. It is remarkable that carbon is rare among the older rocks.4

b. In the Organised Kingdom. — Carbon is an essential constituent of all organised beings, both vegetable and animal.

Properties. — Carbon is a solid, odourless, tasteless substance, neither fusible (?) nor volatile; combustible in oxygen gas, and yielding carbonic acid gas. The other properties of carbon are so varied, that chemists are obliged to admit distinct varieties of this substance: the principal are the diamond, plumbago, and charcoal (animal and vegetable). Of these, the two latter only require consideration in this work.

[Carbon, like oxygen, is now considered to assume the allotropic form, and to show varying chemical reactions in consequence. The diamond and plumbago must be regarded as merely allotropic forms of ordinary carbon. — Ed.]

Ei kommentteja :