Democratic Sentinel, Volume 8, Number 44, Rensselaer, Jasper County, 28 November 1884 — Some Strange Metals. [ARTICLE]

Some Strange Metals.

Some of the metals which are familiar enough to the chemist, though rarely seen outside his laboratory, have so little in oemmon with the metals of every-day life as to scarcely seem to belong to the same class of substances. We commonly think of a metal as being heavy, yet sodium and potassium will float on water and lithium is the lightest of all known soKds. The fact is that the word “metal’* is one of the hardest in the language to define. The metals an have a peculiar luster, to be Bure, which, from its association, has come to be called metallic; but many minerals, as galena and black-lead, which most certainly are not metals, have the same appearance, and so on through the list of properties. The ehemical relations of the metals give good reasons for placing these substances by themselves, though even here the lines are not clearly marked. One of the most distinctive properties of the metals is their power to form, when combined with acids, a class of bodies called salts—on account of their resemblance to common salt, which contains about 40 per cent, of the metal sodium. This metal is a bluish white, waxy solid, and has such a great tendency to rust, or unite with the oxygen in the air, that it must be kept in some oil, like petroleum, which contains no oxygen. if a bit of sodium be thrown upon a piece of ice, the metal takes fire, and any attempts to put it out by pouring water on it would only be adding fuel to the flame. The sodium-match is an application of this peculiar property of the metal. It is merely a bit of wood tipped with sodium, and whicfy can, of course, be lighted on the stormiest day by the mere contact of a rain-drop. The matches are, however, decidedly dangerous, and their manufacture is generally prohibited. which is obtained from potash, is another metal very similar to sodium, and will take fire upon ice or water even more readily than this lastnamed metal. A small piece of potassium thrown into a jug of water apparently takes fire at once, and swims about with great rapidity, burning all the time with a brilliant violet flame. One may be forgiven if his ideas on combustion are somewhat upset by the first sight of this phenomenon, but there is really nothing very strange about it. Water is a compound of hydrogen and oxygen, and these «metals, sodium and potassium, have so strong an attraction for oxygen that they will take it wherever they can find it, even from water. This, of course, sets the oxygen free, which is sef on fire by the heat given off when the potassium and oxygen unite, and burns with a violet color because of the vapor of the metal. The same is true in the case of sodium; the flame is due to the burning hydrogen rather than the metal. Sodium, potassium, and lithium, with several other metals, form a group known as the alkali metals. There is another group, to which iron belongs, which contains an interesting member called aluminum—sometimes aluminium—from its occurrence in common alum. Aluminum is a beautiful metal, much like silver in appearance, and possessing many valuable properties. It is very sonorous, easily worked, does not tarnish in the air, and is only about one-fourth as heavy as silver. It conducts electricity eight times better than iron. Added to this, it occurs in greater quantity than any other metal in the world. Every clay-bank, every granitebed, is a bed of aluminum, but as yet no cheap and ready means of obtaining the metal has been found in spite of all attempts. Napoleon offered a large reward to any one discovering such a process, as, on account of its lightness, he wished to use the metal in his army for helmets and cuirasses. It is hardly possible to give an exact statement of the amount of aluminum in different days, since the composition of these earths varies greatly. Clays are impure silicates of aluminum, and, generally speaking, a good brick clay contains a tenth dr more by weight of the metal. This would be sufficient to plate the upper surface of the bricks, as they are commonly laid in sidewalks, with a layer of metallic aluminum a fifth of an inch deep* Or this samq amount of metal would form a layer one-third of an inch deep on the outside of the brick, as they are laid in our homes. So we find this hidden,* metal everywhere about us, and a princely fortune waits the man who caif bring it to the light.