Читать книгу Description of the Process of Manufacturing Coal Gas. For the Lighting of Streets Houses, and Public Buildings онлайн

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ssss1 Other Substances from which carburetted hydrogen gas, may be economically obtained, are animal and vegetable oil, tar, both vegetable and coal tar; pitch, resin, the essential oils obtainable from vegetable and from coal tar, and the compact species of turf. On this subject we shall speak hereafter.

The principal coal mines in England are those near Newcastle and Whitehaven. The town of Newcastle stands on beds of coal which extend to a considerable distance round the place, and which as far as concerns many hundred generations after us, may be pronounced inexhaustible.

Pitcoal like all other bituminous substances is composed of a fixed carbonaceous base in the state of bitumen, united to a small portion of earthy and saline matter, which constitute the ashes left behind when the coal is burnt. The proportions of these parts differ considerably in different kinds of coal; and according to the prevalence of one or other of them, so the coal is more or less combustible, passing by various shades from the most inflammable coal into blind coal, Kilkenny coal, or stone coal, and lastly into a variety of earthy, or stony substances, which although they are inflammable do not merit the appellation of coal.