“ Mercury, within a certain range of temperatures situated close to its boiling point, combines slowly with oxygen into the red oxide, which, however, breaks up again at higher temperatures. All other metals, when heated in oxygen or air, are converted, more or less readily, into stable oxides. ”

“ Among these the softness decreases in about the following order: lead, pure silver, pure gold, tin, copper, aluminium, platinum, pure iron. As liquidity might be looked upon as the ne plus ultra of softness, this is the right place for stating that, while most metals, when heated up to their melting points, pass pretty abruptly from the solid to the liquid state, platinum and iron first assume, and throughout a long range of temperatures retain, a condition of viscous semi-solidity which enables two pieces of them to be “welded” together by pressure into one continuous mass. ”

“ Silicon, so far as we know, behaves to metals pretty much like carbon, but our knowledge of facts is limited. What is known as cast iron is essentially an alloy of iron proper with 2 to 6% of carbon and more or less of silicon (see Iron) . Alloys of copper and silicon were prepared by Deville in 1863. The alloy with 12% of silicon is white, hard and brittle. ”

“ One chemical differentia utilizes the fact that metals always form at least one basic oxide which yields salts with acids, While non-metals usually form acidic oxides, i.e. oxides which yield acids with water. This definition, however, is highly artificial—and objectionable on principle, because when we speak of metals we think, not of their chemical relations, but of a certain sum of mechanical and physical properties which unites them all into one natural family. ”

“ These frozen metals in general form compact masses consisting of aggregates of crystals belonging to the regular or rhombic or (more rarely) the quadratic system. Compared with non-metallic solids, they in general are good conductors of heat and of electricity. But their most characteristic, though not perhaps their most general, property is that they combine in themselves the apparently incompatible properties of elasticity and rigidity on the one hand and plasticity on the other. ”

“ By the “hardness” of a metal we mean the resistance which it offers to the file or engraver's tool Taking it in this sense, it does not necessarily measure, e.g. the resistance of a metal to abrasion by friction. ”

“ Hence tin and lead, though very malleable, are little ductile. The quality of plasticity is developed to very different degrees in different metals, and even in the same species it depends on temperature, and may be modified by mechanical or physical operations. ”

“ Aqueous Sulphuric or Hydrochloric Acid readily dissolves groups 1 and 2, with evolution of hydrogen and formation of chlorides or sulphates. The same holds for the following group (A) : [manganese, zinc, magnesium] iron, aluminium, cobalt, nickel, cadmium. Tin dissolves readily in strong hot hydrochloric acid as SnCl2; aqueous sulphuric acid does not act on it appreciably in the cold ”