CARBON. Carbon is one of the most common, as it is one of the most important substances in nature, occurring in a great variety of forms, in the animal, vegetable and mineral kingdonis. In both the vegetable and animal kingdoms it is the most considerable element. Charcoal may be con sidered the type of carbon, since, prepared from animal and vegetable substances, it is pure, or nearly so. Lampblack is also nearly pure carbon. The carbon of anthracite coal is pure. The dia mond is crystallized carbon, and when colorless, is pure and uncontaminated. Carbon resists the influence of many re.agents which powerfully affect other bodies, and to the farmer it is one of the most important of the elements. In vegeta tion it is taken up by plants as carbonic acid. If one atom of carbon is combined with two atoms of oxygen, it forms carbonic acid, and these ele ments compose the organic part of all plants. This is contained in the air alone in sufficient quantity for the growth of plants. Although the
air contains only 1-10,000th parts of carbonic acid, yet so enormous is the supply that the atmosphere of the earth contains 3,400,000,000, 000 tons of car bonic acid or about twenty-eight tons for each acre of the earth's surface. The supply is main tained by the oxydation of carbon in the decay of all organic matter, in the respiration of animals, and in the combustion of fuel. In the animal economy carbon is one of the most essential ele ments. Starch, sugar and the gum of plants, fur nish carbon. The fat of animals is largely com posed of carbon, and large amounts are exhaled in the form of carbonic acid by animals in the act of breathing. Carbon constitutes about 42.47 per cent. in sugar, 41.906 per cent. in gum, 43.55 per cent. in wheat starch, 52.58 per cent. in the wood of the oak, and 51.45 in that of the beech; 46.83 in pure acetic acid or vinegar, 36.167 in tartaric acid, and 41.369 in citric.