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 
cmployed is stated to consist of copper 88:00, nickel 8°75, sulphur 
with a little antimony 0°75, silex, clay, and iron 1°75. A similar 
alloy is well known in China, and is smuggled into various parts of 
tie Hast Indics, where it is called packjong. It has been sometimes 
identified with the Chinese tutenaguc. 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 aud Jamaica also have used a nickel alloy for coins. 
Nickel is mostly uscd 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 prcduced is about 600 tons. 
URANIUM, 
Uranium ores have a specific gravity not above 7, and a 
hardness below 6. The ores arc either of some shade of light 
grcen or yellow, or they are dark brown or black and dull, or 
submetallic and without a metallic Instre 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 submetallicordull. Streak black. Opaque. 
T5-8) Gs. = 647, : . 
— Composition. 75 to 87 per cent. of uranium oxides with 
silica, lead, iron, and some other impurities. Related to 
the spinel group. 8B.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 Redruth. In the United States, very spar- 
ingly at Middletown, Redding, and Haddam, Conn.; in North 
Carolina; on the north side of Lake Superior (Coracite). 
