A continuance of decomposition changes this lignite into common or bituminous coal, chiefly by the discharge of Carbureted hydrogen, or the gas by which we illuminate our streets and houses.
"The Student's Elements of Geology"
Sir Charles Lyell
Relation of oxygen to nitrogen; amount of carbonic acid; Carbureted hydrogen; ammoniacal vapors.
"COSMOS: A Sketch of the Physical Description of the Universe, Vol. 1"
Alexander von Humboldt
16, 21. In the first place we would mention the respiration of animals, who receive the carbon which they inhale from vegetable food, while vegetables receive it from the atmosphere; in the next place, carbon is supplied from the interior of the earth in the vicinity of exhausted volcanoes and thermal springs, from the decomposition of a small quantity of Carbureted hydrogen gas in the atmosphere, and from the electric discharges of clouds, which are of such frequent occurrence within the tropics.
"COSMOS: A Sketch of the Physical Description of the Universe, Vol. 1"
Alexander von Humboldt