Some Information Concerning Gas Lights Author:Thomas Cooper Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: CHAPTER III. Of the products of distillation of coal and wood. When coal is burnt in an open fire, as the coals become hot, there appears a dense white smo... more »ke occasionally pervaded by flame, which is sometimes bright and sometimes goes out; by degrees the smoke becomes less, the flame more steady, till the whole mass becomes red-hot, and then the smoke and flame cease. In the first part of the process, vapour and uncombustible gases mingle with the carburrettdd hydrogen or inflammable coal gas; when these have escaped and formed soot, then the coal gas burns steadily, till it leaves nothing but red hot coke. Such also are the appearances of wood burnt in an open fire, though somewhat less marked. When coal is distilled in a close iron vessel, as in the process for making coal gas, there comes over (when the smoke is condensed) 1st. A thick bituminous substance of the nature of tar. 2d. A watery fluid containing in solution carbonat of ammonia, and some other ammoniacal salts. 3d. An empyreumatic stinking oil that is partly mixed with, and partly swims on the top of this ammoniacal liquor, and partly dissolved in the gases that escape. 4th. Volatile gases, consisting of carburetted hydrogen, carbonic oxyd, and carbonic acid, whereof the first only is inflammable or combustible, and is injured by being mixed with the other gases which are not so. Such are the products of the distillation when the heat employed does not exceed a full red heat. If it be urged to a full .white heat quickly applied, part of the tarry substance and the empyreumatic oil are also converted into these gases. In the retort there remains the charcoal of coal, that is coke; which strongly approaches in its chemical composition to anthracite. It is the substance generally used in Engla...« less