SILVER. 497 
The veins of metal were found to be much richer 
towards the surface than deep within the mountain, 
so that the working of this mine is now discon- 
tinued. 
The most remarkable mine of silver in Spain is 
that of Guadalcanal in Andalusia, which was for- 
merly very rich, and well known to the Romans. 
It is situated in the Sierra Morena , or black moun- 
tain, on the confines of Andalusia and Estramadura, 
fifteen leagues to the north of Seville, and several 
miles to the north-east of the famous quicksilver 
mine at Almaden. The mineral obtained here is 
the ruby silver ore. 
But it is in the centre of the Andes, in situations 
which, though immediately exposed to the perpen- 
dicular rays of the sun, are constantly covered with 
snow, that Nature has most abundantly distributed 
this metal. In twenty degrees of southern latitude, 
within the torrid zone, we find the famous moun- 
tain of Potosi, situated near the source of the Rio 
de la Plata. This mountain is one of the most 
considerable in Peru; its height is immense; and 
it appears from the descriptions of travellers, that 
from top to bottom it is full of veins of silver. 
When these mines were first discovered in the 
year 1545, the veins were so rich as to be almost 
entirely composed of silver without any mixture. 
At present, however, the produce is very different, 
scarcely more than five drams being obtained from 
a hundred weight of ore ; still, from the great 
2 K 
VOL. III. 
