Element Cobalt, Co, Transition Metal. Have been known for millennia. Glass ingots have been recovered from Egyptian ancientries such as jar dating to the 15. , in coloring of which cobalt salts. Had been used, as well as in the cobalt. Ancient Assyrians and Babylonians used to produce blue paints which were used for ceramics glazing. Contained sapphire was the initial material from which the names of blue paints came.

Element Copper, Cu, Transition Metal. Between the metals of the new group, which is called after copper. Of the heavy metals already discussed, copper. Besides being used in the pure state, copper. Is also extensively employed for alloys. Brass has already been mentioned; others will be given later. Of the Sinai Peninsula were extensively worked by the Egyptians about the year 3700 b. Must have been known in Cyprus for many centuries previous to their production. Copper daggers found in Northern Italy .

Element Palladium, Pd, Transition Metal. Was discovered by William Hyde Wollaston in 1803, also in raw platinum, in the part soluble in aqua regia. When Wollaston separated some quantity of the metal, he, without reporting about the discovery, distributed anonymous advertising about new metal named palladium. This element was named by Wollaston in 1804 after the asteroid Pallas, which was discovered by named by astronomer Heinrich Wilhelm Matthäus Olbers two years earlier.

Element Rhodium, Rh, Transition Metal. Was discovered in 1803 by William Hyde Wollaston, soon after his discovery of palladium. Wollaston dissolved raw platinum in aqua regia. The acid surplus was neutralized by caustic soda. He then precipitated the platinum by adding ammonium chloride, NH. Cl; palladium was removed as palladium cyanide after treating the solution with mercuric cyanide.

On account of its remarkable properties and of its occurrence in the metallic state, silver. In the pure state silver is a white tenacious metal, which can be readily drawn into wire, and made into very thin sheets by rolling or hammering. For use it is alloyed with 10 per cent of copper in order to make it harder. It conducts heat and electricity very well, and occupies, in this respect, the first place among the metals. Is also found in native form.