Page:Experimental researches in chemistry and.djvu/52

1820] chloride is to be collected on a filter, and dried as much as may be, by pressure between folds of bibulous paper. It should next be introduced into a glass tube, and sublimed by a spirit-lamp: the pure substance with water will rise at first, but the last portions will be partially decomposed, muriatic acid will be liberated, and charcoal left. The sublimed portion is then to be dissolved in alcohol, and poured into a weak solution of potash, by which the substance is thrown down, and the muriatic acid neutralized and separated; then wash away the potash and muriate by repeated effusions of water, until the substance remains pure; collect it on a filter, and dry it, first between folds of paper, and afterwards by sulphuric acid in the exhausted receiver of the air-pump.

It will now appear as a white pulverulent substance; and if perfectly pure, will not, when a little of it is sublimed in a tube, leave the slightest trace of carbon, or liberate any muriatic acid. A small portion of it dissolved in:ether should give no precipitate with nitrate of silver. lf it be not quite pure, it must be re sublimed, washed, and dried until it is pure.

This substance does not require the direct rays of the sun for its formation. Several tubes were filled with a mixture of one part of olefiant gas with five or six parts of chlorine, and placed over water in the light of a dull day; in two or three hours there was very considerable absorption, and crystals of the substance were deposited on the inside of the tubes. I have also often observed the formation of the crystals in retorts in common daylight.

A retort being exhausted had 12 cubic inches of olefiant gas introduced, and 24.75 cubic inches of chlorine: as soon as the condensation occasioned by the formation of the fluid had taken place, 21.5 cubic inches more of chlorine were passed in, and the retort set aside in a dark place for two days. At the end of that time muriatic acid gas and the solid chloride had formed, but the greater part of the fluid remained unchanged. Hence it will form even in the dark by length of time. I tried to produce the chloride by exposure of the two gases in tubes over water to strong lamp-light for two or three hours, but could not succeed.

The per chloride of carbon, when pure, is, immediately after fusion, or sublimation, a transparent colourless substance. It