198 PYRITES. 
derable proportion of metal. It makes excellent bar 
iron, but very indifferent cast iron. In Sweden, and 
particularly at Roslager, magnetic iron stone is found 
quite pure, and the iron that is wrought from it is im- 
ported in considerable quantities into Great Britain, for 
the purpose of being manufactured into steel. 
The appellation of load, or leading stone, has been 
given to this kind of iron from its magnetic virtues ; 
for it is not only endowed with the property of attracting 
iron, but also of pointing itself, and even enabling a 
needle touched with it to point, towards the poles of the 
world. We are, however, entirely ignorant what is the 
cause of this very extraordinary property. 
Artificial magnets, constructed of steel, not only pos- 
sess all the essential virtues of the genuine loadstone, 
but even in a much higher degree. The natural mag- 
net is consequently now little esteemed except as aa 
object of curiosity. 
236. PYRITES, or MARCASITE, is a mineral sub- 
stance, formed by a combination of iron with sulphur. 
It is usually of a bronze, yellow, or brownish colour, very 
various in form, being massive, globular, club-shaped, oval 9 
or crystallized; and so hard as to strike fire with flint. 
Few minerals are more common than this, as it oc- 
curs, in some state or other, in almost every rock and 
vein. It is often found among coals ; and, when, 
heated, decrepitates with a loud unpleasant noise and 
sulphureous smell. To the decomposition of this mine- 
ral it is that the hot temperature of almost all the mine- 
ral waters may be ascribed. 
The name of pyrites, which in the Greek language 
signifies firestone, has been obtained by this mineral 
from its property of striking sparks from steel. It was 
formerly used for fire-arms, as we now use flints. In 
commerce it is known by the name of marcasite. Some 
years ago it was much used, particularly in France, for 
the making of buttons and buckles ; and was cut and 
polished, by lapidaries, for trinkets, particularly for the 
rims and hands of watches, and various kinds of female 
