METALS. Elementary bodies, remarkable for their luster ; they conduct electricity and heat, and are negative clectrics. Of the peculiarities of some of the metals, Appleton's New Cy clopTdia says: The peculiar brilliancy and reflec tive power of the metals,which may be enhanced by polishing, results from their great opacity. The color of the metals is generally white with a grayish, bluish, or pinkish tint; copper and gold are the only exceptions. In extremely thin films some of the metals allow the passage of certain rays of light. Gold leaf transmits light of a faint greenish hue. Most of the metals have a high specific gravity, a property which was regarded as characteristic until the discovery of the alkaline metals, which are lighter than water. With the exception of arsenic, they may all be fused, the temperature required for fusion varying from 100° F. to the highest heat of the oxy-hydrogen blowpipe. Some of the metals rnay be volatilized. Mercury, the only liquid
metal, is solidified at-39° F. Arsenic when heated passes directly into vapor without fusion. Most of the metals possess a certain mobility of particles that allows of their being extended or otherwise altered in form. The two nearly related properties of malleability and ductility, resulting from this, are not possessed by the metals in the same degree. A few of them, as antimony, arsenic, and bismuth, are decidedly brittle. Some assume a plastic condition before complete fusion, notably iron and platinum; on this property depends the operation of welding. The strength of the metals is very dissimilar, iron in the form of wire being about twenty-six times as tenacious as lead. They are all con ductors of heat aud electricity, although differ ing widely in this respect. The following table gives their names, specific gravity, and melting points: