On the constitution and properties of picoline : a new organic base from coal-tar / [Thomas Anderson].

  • Anderson, Thomas, 1819-1874
Date:
1846
Catalogue details

Licence: Public Domain Mark

Credit: On the constitution and properties of picoline : a new organic base from coal-tar / [Thomas Anderson]. Source: Wellcome Collection.

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    also quite distinct from those presented by aniline. When brought in contact with the solution of chloride of lime, it does not produce, in the least degree, the violet colour which is so characteristic of aniline; on the contrary, the solution remains perfectly colourless, unless, indeed, the picoline has not been well separated from pyrrol; in which case, a slight brown makes its appearance, but no violet. Picoline is also incapable of producing the yellow colour in fir wood and the pith of the elder, which is so readily obtained with aniline. When treated with chromic acid, even when very concen¬ trated, and after boiling, no change takes place in the colour of the solution, and only a small quantity of a yellow powder is deposited; while aniline gives an abundant precipitate, which has, according to the degree of concentration of the fluid, a green, blue, or black colour. Picoline precipitates from solutions of chloride of copper a portion of the oxide of copper, while the remaider forms a pale blue solution, which, when evaporated to a small bulk, deposits a congeries of prismatic crystals, which seem to be a double salt. No blackening of the solution takes place, as is the case with aniline. When an excess of hydrochloric acid is present, there is obtained, on evaporation, another double salt in large crystals, apparently derived from the rhombohedral system. Picoline produces also double compounds with the chlorides of mercury, platinum, gold, tin, and antimony. With chloride of gold it gives an exceedingly characteristic com¬ pound, in the form of a fine lemon-yellow precipitate, which is soluble in a considerable quantity of boiling water, and is deposited, on cooling, in delicate yellow needles. Aniline, under similar circumstances, gives a reddish-brown precipi¬ tate, resembling the ferrocyanide of copper. It gives, with infusion of nut-galls, a copious curdy precipitate of a pale- yellow colour, which dissolves in hot water, and is deposited again on cooling. It does not precipitate the solutions of nitrate of silver, chlorides of barium and strontium, or sul¬ phate of magnesia. The properties of picoline, as now detailed, are obviously different from those of aniline. They recalled, however, strongly to my mind those of a base called Odorin, obtained