When calcium sulphate is present, the nascent methane induces the formation of calcium carbonate, sulphuretted hydrogen and water.
Chem., 1888, 2, p. 553), who prepared the four nitromethanes, CH 3 N 2 0, each atom in methane being successively replaced by the nitro-group.
Water decomposes it, giving methane and hydrogen (H.
Von Liebig (Ann., 1908, 360, p. 128), from a very complete discussion of triphenyl methane derivatives, concluded that the group i ng A A A was the only true organic chromophore, colour production, however, requiring another condition, usually the closing of a ring.
In carburetting poor coal gas with hydrocarbons from mineral oil it must be borne in mind that, as coal is undergoing distillation, a rich gas is given off in the earlier stages, but towards the end of the operation the gas is very poor in illuminants, the methane disappearing with the other hydrocarbons, and the increase in hydrogen being very marked.
A further generalization was effected by August Kekule, who rejected the hydrochloric acid type as unnecessary, and introduced the methane type and condensed mixed types.
But here again another mistaken idea arose, owing to a faulty method of estimating the benzene, and there is no doubt that methane is one of the most important of the hydrocarbons present, when the gas is burnt in such a way as to evolve from it the proper illuminating power, whilst the benzene vapour, small as the quantity is, comes next in importance and the ethylene last.
Prior to 1830, little was known of the process other than that organic compounds generally yielded tarry and solid matters, but the discoveries of Liebig and Dumas (of acetone from acetates), of Mitscherlich (of benzene from benzoates) and of Persoz (of methane from acetates and lime) brought the operation into common laboratory practice.
Discovered by Boyle in 1661, it was first carefully studied by Dumas and Peligot in 1831; its synthesis from its elements (through methane and methyl chloride) was effected by Berthelot in 1858.
Its tetramethyl-diamino derivative, which is formed by condensing formaldehyde with dimethyl-meta-aminophenol and subsequent elimination of water from the resulting diphenyl methane derivative, is the leuco base of pyronine, into which it passes by oxidation.