Chlorine, Dephlogisticated

MARINE ACID, OXY MURIATIC ACID, n. [Gr. chloros, green) ( Chem.) A non-metallic element discovered by Scheelo in 1774, while examining. an ore of manganese. It was thought at first to be a compounded gas; but Gay-Lu ac and The nard supposed, and Sir Humphrey Davy proved, that it was an elementary body. It was the latter philosopher that bestowed upon it the name of chlorine, from chloros, green (Greek), on account of its color. It occurs in nature in great abundance, in combination with many mineral substances, such as rock-salt; also in sea-water and sea plants, as the chlorides of pota ium and sodium. It may be prepared in two ways, -either by heating black oxide of manganese with hydrochloric acid, or by heating a mixture of black oxide of manganese, chloride of sodium, and dilute sulphuric acid. It is a transparent gas of a greenish-yellow color and a powerfully suffocating odor, which, even largely diluted with air, produces great irritation of the air-pa ages. One hundred cubic inches weigh between 77 and 78 grains. It is, therefore, about two and a half times heavier than atmospheric air. Water absorbs about twice its volume; it can, therefore, be only collected by displacement or over warm water. Under a pre ure of four atmospheres it condenses into a yellow limpid liquid, rather heavier than water, and remains fluid and unfrozen at a temperature of 220° Fahr. With water, chlorine forms a definite hydrate, which, when subjected to a cold of 32° Fahr., solidities in the form of large yellow crystals. Chlorine is not combustible, but supports combustion to a certain degree. A wax taper burns in it with a reddish smoky flame, the hydrogen of the wax combining with the chlorine to form hydrochloric acid, and the carbon being set free. Chlorine, in common with several other elementary bodies, has the property of replacing hydrogen in its organic compounds. It is in this manner that chlorine bleaches textile fabrics. The brownne of the fabric is due to some brown organic substance, which, when submitted to the action of chlorine, parts with its hydrogen and a umes a colorle form, containing chlorine. This fact is proved on a large scale by the action of chlorine on indigo. Another property of chlorine is that of destroying noxious vapors and miasmata. For the same reason, it is used as a disinfectant, the action being the same as that mentioned above. For laboratory use, chlorine is best made as follows: - Oil of vitriol and water, of each seven parts. Allow the mixture to cool, and add four parts of chloride of sodium, mixed alternately with three parts of peroxide of manganese. The gas comes off slowly at first until the application of a gentle heat, when it immediately rushes forth in large quantities. The manufacture of chlorine for bleaching purposes is described under BLEACHING-POWDER. Chlorine is po e ed of powerful affinities, and unites with all the metalloids and metals. With oxygen it forms five compounds,-hypochlorous acid, CIO; chlorous acid, CIO3; peroxide of chlorine, or hypo chloric acid, C1O4; chloric acid, C105;1 perchloric acid, C107; all of which are described under their respective heads. With hydrogen it forms hydrochloric acid, and with nitrogen a fearfully explosive substance-perchloride of nitrogen. With carbon it forms several chlorides. (See CARBON.) In many of its properties it bears a very strong analogy to its congeners bromine and iodine (q. v.).-Equivalent, 35-4; sp. grav., 2.44; symbol Cl.