URANIUM. 169 



imitation of silver, or mix it with silver for sale. " White copper" 

 has long been used in Saxony for various small articles ; the alloy 

 employed is stated to consist of copper 88*00, nickel 8*75, sulphur 

 with a little antimony 75, silex, clay, and iron 1*75. A similar 

 alloy is well known in China, and is smuggled into various parts of 

 the East Indies, where it is called packfong. It has been sometimes 

 identified with the Chinese tutenague. M. Meurer analyzed the white 

 copper of China, and found it to consist of copper 65*24, zinc 19 52, 

 nickel 13, silver 2 5, with a trace of cobalt and iron. Dr. Fyfe ob- 

 tained copper 40*4, nickel 31*6, zinc 25*4, and iron 26. It has the 

 color of silver, and is remarkably sonorous. It is worth in China 

 about one -fourth its weight of silver, and is not allowed to be carried 

 out of the empire. 



An alloy of 88 per cent, copper and 12 per cent, nickel is the mate- 

 rial of the United States cent, introduced in 1851. Switzerland, Bel- 

 gium and Jamaica also have used a nickel alloy for coins. 



Nickel is mostly used at the present time for nickel-plating by 

 electro deposition. The value of the metal in commerce rose in the 

 years 1870 to 1875, from $1.25 to $3.00 per pound. The amount 

 annually produced is about 600 tons. 



URANIUM. 



Uranium ores have a specific gravity not above 7, and a 

 hardness below 6. The ores are either of some shade of light 

 green or yellow, or they are dark brown or black and dull, or 

 submetallic and without a metallic lustre when powdered. 

 They are not reduced when heated with carbonate of soda ; 

 and the brown or black species fuse with difficulty on the 

 edges or not at all. 



Uraninite. — Pitchblende. Uranium Oxide. 



Isometric. In octahedrons and related forms. Also mas- 

 sive and botryoidal. Color grayish, brownish, or velvet- 

 black. Lustre submetallic or dull. Streak black. Opaque. 

 H.=5-5. G.=6-47. 



Composition. 75 to 87 per cent, of uranium oxides with 

 silica, lead, iron, and some other impurities. Eelated to 

 the spinel group. B.B. infusible alone ; a gray scoria with 

 borax. Dissolves slowly in nitric acid, when powdered. 



Obs. Occurs in veins with ores of lead and silver in 

 Saxony, Bohemia, and Hungary ; also in the tin mines of 

 Cornwall, near Eedruth. In the United States, very spar- 

 ingly at Middletown, Eedding, and Haddam, Conn. ; in North 

 Carolina ; on the north side of Lake Superior (Coracite). 



