Platina may be had in fine powder, by dissolving it in ammonia-muriate, and heating it in a crucible to redness, till no more fumes arise. It then resembles sponge.
Zinc is reducible to fine powder when hot, if pounded by a heated iron mortar in a heated pestle.
When platina is alloyed with other metals, it becomes soluble with them.
Besides the alloys enumerated as alloys, steel 500, and silver 1, produce a fine cutting metal.
Steel, too, alloys with rhodium, in razors made at Sheffield ;• and with gold and nickel, also with platinum, in the proportion 1 platinum, 8 steel, with the finish polish.
All the metallic nitrates are soluble. The muriates generally. The sulphates are insoluble, except by solutions of barv tie salts. The acetates are Soluble. The alkaline earths are soluble in solutions of sugar. Tortrates render many metallic oxides soluble.
Dr. Thomson divides metals into four classes. 1. Malleable metals. Platina, gold, silver, nickel, mercury, palladium, rhodium, iridium, 9smium, copper, iron, tin, lead, and zinc. 2. Brittle and easily
fused. Bismuth, antimony, tellurium, and arsenic. 3. Brittle and difficult of fusion. Cobalt, manganese, chrome, molybdena, uranium, tungsten, and tit anium. 4. Refractory, or such as have never yet been reduced. Columbium, tantalium, and cerium.
Metals, like other fusible bodies, have each a fixed temperature, or freezing point, at which they become solid. The specific gravity is considerably affected by the gradual or hasty cooling, or tran sition from the fluid to the solid state. Hammering renders them harder and more elastic ; but this effect is destroyed by ignition.
They combine with hydrogen intc hydrurets ; with carbon, into earburets ; with sulphur, into suWatrets ; with phos phorus, into phosphurets ; with selenium, into selenfurete ; with boron, into borurets (halides?); with chlorine, into chlorides, with iodine, into iodides; with cyanogen, into cyanides; with silicon, into silimdes and with fluorine, into fluorides.