ON MET.LS. 26d

“. It is; for it takes an impression in coming verv
well, and its value is a proper proportion below silver
‘or a price for the cheapest commodities. In some
poor countries, they have little other than copper coin.
Another great use of copper is as an ingredient in
mixed metals; such as bell-metal, cannon-metal, and
particularly brass.

#1, But brass is yellow.

L. True; it is converted to that colour by means of
another metallic substance, named zinc, or spelter, the
natural colour of which is white. Zine, as much
cheaper than copper, and less liable to corrode, has
been extensively brought into use of late years, for a
variety of purposes. A kind of brown stone called
calamine, is an ore of zine. By filling a pot with
layers of powdered calamine and charcoal, placed al-
ternately with copper, and applying a pretty strong
heat, the zinc is driven in vapour out of the calamine,
and penetrates the copper, changing it into brass.

G. What is the use of turning copper into brass P

7. It gains a fine, gold-like colour, and becomes
harder, more easy to melt, and less lable to rust.
Hence it is preferred for a variety of utensils, orna-
mental and useful. Brass does not bear hammering
well, but is generally cast in the shape wanted, and
then turned in a lathe and polished. Well—these are
the principal things I have to say about copper.

HH. But where does it come from ?

7. Copper is found in many countries. Our island
yields abundance, especially in Wales and Cornwall.
In Anglesey is a whole hill, called Paris-mountain,
consisting of copper ore, from which immense quan-
tities are dug every year. Now for zron.

Hf, Ay! That is the most useful of all the metals.

T. I think itis; and it is also the most common,
for there are few countries in the world possessing
hills and rocks, where it is not met with, more or less.
Tron is the hardest of metals, the most elastic or
springy, the most tenacious or difficult to break, next
to gold, the most dificultly fusible, and one of the