44* 
Mercury. 
Symbol , H(j. (Hydrargyrum); atomic weight , 200; specific gravity , 25*5. 
It lias been known from very remote times, certain of its compounds being 
used by the Greeks. In colour it is silver white, and from its resemblance to that 
metal in colour, and from the fact that it is liquid at ordinary temperature, it 
has been called quicksilver. It becomes solid at a temperature of 4Cr F., when 
it is both ductile and malleable, and starts to volatilise at tl6° F., and boils afc 
682° F. It is easily distinguished from other metals by the fact that it is Liquid. 
Mercury is used largely in gold and silver saving, for silvering mirrors, the manu¬ 
facture of thermometers, and in medicine under the names of white and red 
precipitate, calomel, corrosive sublimate, and blue pills; the red colour called 
vermilion is also a salt of mercury, and it may be here mentioned that all salts of 
mercury are poisonous. It occurs in nature in the metallic state, mostly alloyed 
with other metals forming native amalgam, but most commonly ms a sulphide. 
Cinnabar . — Mercury sulphide.—This occurs both crystalline and massive and 
earthy, of a bright red to brownish black colour, with a brilliant lustre, its streak 
being scarlet red. 
It is subtransparent to nearly opaque, it hardness being 2*5, specific gravity 
9, and its composition sulphur, 13-8, mercury, 86*2. It is distinguished from any 
other mineral by vapourizing before the blow-pipe. It lias never yet been found 
in this Colony. 
Copper. 
Symbol , Cu. (Cuprum) ; atomic weighty OS'4; specific gravity, 8’84. 
Copper has been known and worked from the earliest times, and was used as 
an alloy with T V its weight of tin in the manufacture of tools and weapons long 
before iron was worked. 
It is of a deep red colour when seen in a mass, and does not oxidise at 
ordinarv temperature iu dry air, but in damp air, when acid vapours are present, it 
becomes coiToded with a green substance called “ verdigris.” It also becomes 
coated with a reddish-brown oxide when heated in the presence of air, and loses 
its metallic lustre. 
Its hardness is about 3, but this is greatly increased by hammering or 
rolling. 
Its malleability and ductility is less than gold, silver, or platinum, but its 
tenacity is greater than any other metal except iron. 
It melts at a temperature of 1990° F., and when raised to a white heat gives 
off metallic fumes which colour a flame green. 
It is the next best conductor of heat and electricity to silver, and is largely 
used for the latter purpose owing to the fact that it is much cheaper than silver 
and is more tenacious. 
Copper occurs in nature in the metallic form, but also and more commonly as 
the following compounds : — 
Ghalcopyrite . — Copper pyrites, copper and iron sulphide. This ore is generally 
met with in depth, sometimes crystalline but most generally massive. It is of 
a brass yellow colour, and tarnishes deep yellow, which is often iridescent. The 
streak is' non-metallic and shining, of a greenish black. Its hardness is about 
4, and its Specific gravity 4T5. 
Its composition is sulphur, 34*9 ; copper, 34’6; iron, 30*5. 
It is distinguished from gold, as it crumbles instead of cutting, and from iron 
pyrites, as it can be scratched with a knife. It fuses to a blackish magnetic 
globule on charcoal, owing to the iron present. 
