Lessons in Elementary Chemistry, Inorganic and Organic (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1868 edition. Excerpt: ...which a solution of cobalt chloride imparts to these salts when heated before the blowpipe. 3. Cadmium. Symbol Cd. Combining Weight 112. Specific Gravity 86. This is a comparatively rare metal, occurring in certain zinc ores. In its chemical relations it closely resembles znc. It is, however, more volatile than the latter metal, and therefore distils over first in the preparation of. zinc. Cadmium is a white ductile metal, melting at 3150; it may be easily distinguished and separated from zinc by yielding a bright yellow sulphide insoluble in hydrochloric acid. The metal takes fire when heated in the air, forming a brown oxide, Cd O. The chloride and sulphate are soluble well-crystallizing salts. Cadmium iodide is occasionally used in.photography, and the yellow sulphide has been employed as a pigment. Class V. Iron Class.--1, Manganese. 2, Iron. 3, Cobalt. 4, Nickel. 5, Chromium. 6, Uranium. 7, Indium. 1. Manganese. Symbol Mn. Combining Weight 55. Specific Gravity 8o. Manganese occurs in nature as an oxide, and it can be obtained, though with difficulty, in the metallic state by heating the oxide very strongly with charcoal. The metal is of a reddish-white colour; it is brittle, and hard enough to scratch glass. It decomposes water at the ordinary temperature with evolution of hydrogen; it cannot be preserved in the air without undergoing oxidation, and must be kept under naphtha, or in a sealed tube; it is slightly magnetic, and, like iron, combines with carbon and silicon. Metallic manganese is not used in the arts, but an alloy of this metal and iron is now made on a large scale, and used in the manufacture of steel. Some of its oxides are used for the purpose of evolving chlorine from hydrochloric acid, and also for tinting glass a purple...