OF THE MENAI BASIN. 
249 
cult and expensive operation to separate. But an ingenious 
gentleman, Mr Joseph Jones of Amiooch, has discovered 
a way to accomplish, at little expense, the separation of the 
two metals. To separate it from this very poor ore of 
protosulphuret of copper, or from a slag, he adds a fur- 
ther quantity of protosulphuret, or some substance contain- 
ing it, and thereby gets out not only the portion added, 
but the small quantity not obtainable by common means. 
This operation of separation of copper from poor ores re- 
quires four sm citings before it is accomplished. The sul- 
phur is last burnt off, by throwing wood into the melted 
sulphuret of copper, and in this way pure copper is ob- 
tained. 
The greatest depth of the mine is about SOO feet. The 
excavation has much the appearance of an egg-form, and 
corresponds to the idea which the celebrated Werner threw 
out several years ago, that metallic deposites often are 
found collected into masses of an egg-like figure. 
Not many years ago 1500 men were employed in the 
Paris Mountain copper-mines. But now so much have 
they declined, that perhaps scarcely 500 men find employ- 
ment. 
In 1799, these mines, at an average, annually produced 
30,000 tons of copper-ore; now, perhaps, not a sixth of 
that quantity. The mine seems now nearly exhausted. 
Occasionally sulphate of lead and calamine are found 
mixed with the copper-ore of Paris Mountain, 
