26 
Copper . 
length ; I shall therefore present the reader with other 
accounts, not regarding the chance of some tautology, and 
repetition* 
Reduction of the Ores . 
The reduction of copper ores in the large way is on the 
whole a very simple business, being little else than a suc- 
cession of roasting and reducing processes of the simplest 
kind, till the metal acquires the desired degree of mallea- 
bility and purity. It is to be observed that both arsenic 
and sulphur adhere to copper with great obstinacy, 
even long after it has assumed the appearance of a pure 
regulus, and even in very small proportion they make 
the metal brittle* hard, and difficult to work* 
There are scarcely two works in vffiich precisely the 
same order is observed in the different reducing processes 
(supposing the quality of the ore to be the same) and as 
the manufacturer is generally satisfied with that which 
has been long established and is attended with ordinary 
success, he seldom enquires whether the labour may be 
shortened or the expense diminished* 
The sulphuret of copper which is obtained in such vast 
quantities at the Parys mine in Anglesea, is wrought into 
rough copper in die following manner* The ore is dug 
up in large pieces (being mostly obtained by blasting) 
and is first broken into smallish lumps by the hammer, 
chiefly by women and children, and put into a kiln from 
which proceed flues that open into a very long close pent- 
house gallery to collect the sulphur. The kiln is covered 
close, and a little fire is applied to the mass of ore in dif - 
ferent places, whereby the whole is gradually kindled. 
The sulphur then rises in vapour to the top of the kiln, 
and thence through the flue into the long gallery, where 
it slowly condenses, and is afterwards brushed out and 
further prepared for sale. The mass of ore when once 
kindled continues to bum of itself with a smouldering 
treat for about six months, during which time the sul 
