49 8 
SILVER. 
abundance of mineral, the produce is very con- 
siderable. According to the observations of se- 
veral Spanish naturalists, the mountain of Potosi 
alone, from the time it was first discovered in 1545, 
till the year 1638, that is in the space of ninety- 
three years, hath yielded four hundred millions of 
pesos , or ounces of silver. 
Patrin says, that if we compare the sketch which 
Ulloa has given us of the mountain of Potosi, with 
the description of that of Chalanches, drawn up by 
the learned inspector of mines, M. Schreber, we 
shall see, if not in riches, at least in the physical 
composition of the tw T o mountains, several traits of 
resemblance. 
That of Chalanches, like its fellow in Peru, is an 
alpine mountain of very considerable height, being 
one of the principal summits of the chain which 
stretches to the east of Grenoble. Its sides are very 
steep, and it rises fourteen hundred perpendicular 
fathoms above the level of the sea. All the upper 
part of the mountain is hid in snow, and veins of 
ore appear in every direction and on all sides, from 
the base as far towards the summit as can be traced, 
but the quantity of silver is but trifling. 
Among the mines of the new world, those of 
Mexico must not be forgotten ; they were disco- 
vered after those of Peru, and are now more pro- 
ductive. One of the principal among them is the 
mine of Valenciana, in the district of Guanaxuoto. 
The vein of mineral, which is of a very considerable 
