SILVER. 179 
other countries, after the earthy matters are cleared 
from the silver ore by pounding and washing, the re- 
mainder is melted with lead : which, by a subsequent 
process, is separated, and leaves the silver alone and 
pure. 
This metal ranks next in value to gold. Like gold, 
it is coined into money, and is manufactured into va- 
rious kinds of utensils, such as goblets, vases, spoons, 
and dishes, which have the general appellation of silver 
plate. For all these purposes it is alloyed with copper, 
which does not affect its whiteness, and is not easily 
detected, unless it be in too great proportion : the in- 
tention of this is to render it harder than it would 
otherwise be, and thereby the better to adapt it to re- 
ceive fine and sharp impressions on being cast. Our 
standard silver is composed of somewhat more than 12J 
parts of pure metal and one part of copper ; and the 
metal of this standard is used, both for silver plate, and 
in the coinage. The mark or stamp which is given to 
it at Goldsmiths' Hall is similar to that which has been 
explained for sterling gold. 
After platina (226) and gold (227), silver is considered 
the most unchangeable of all metals. The air does not 
easily act upon its surface in such manner as to injure 
it; but, when long exposed to the atmosphere, especially 
in frequented or smoky places, it acquires a covering or 
rust of dark brown colour, which, on examination, is 
found to be what chemists denominate sulphuret of silver. 
The fumes of sulphur and other inflammable substances 
blacken silver. Various powders have been contrived 
with a view to restore to plate its original lustre ; but 
these should be used with caution, as some of them are 
very injurious. 
Silver is nearly as ductile as gold. It may be beaten 
into leaves so thin that a single grain in weight will 
cover a space of more than fifty-one inches ; and it may 
be drawn into wire much finer than a human hair, in- 
deed so fine that a single grain of silver has, in this 
