On the Quicksilver mine of Santa Barbara, Peru. 7 
to make it valuable. A deep tunnel, commenced during the 
past century, and extended about 200 yards from the foot of the 
promontory, but still six hundred yards from the old workings - 
of the Brocal, is the only mode of developing these beds in 
depth where tradition tells of rich and extensive bodies of ore. 
Extensive workings running to the westward are approached 
by the Puerto de Santo Domingo, standing midway between the 
promontory and the Brocal, Here are numerous large cham- 
bers rapidly going to ruin, excavated in a light-colored sand- 
stone containing cinnabar i in minute quantities, amounting to 
less than half of one per cent. In the same strata with the 
Santa Barbara, and in close proximity, are six or eight other 
mines belonging to private individuals, formerly productive but 
now abandoned. 
In the vicinity of Huancavelica there are no less than forty- 
vein of cinnabar in limestone formerly mined, and where the 
ruins of old furnaces are still to be seen. The ore occurs in 
another vein of realgar containing also mercury, and about five 
feet in thickness. Immediately —— the realgar is a vein 
of a black sooty material of about eleven feet thickness. It 
yo ee to be a decomposed sulphuret, but its characters are 
obse _ This vein is remarkable from its containing selenium, 
sincieijod with sae — arsenic, silver an 
e ores of Santa Barbara mine are all poor, not averaging 
probably over one-half of one per con The ore is frequently 
quite invisible and is disseminated through the rock at times in 
feebly developed veins a few lines in thickness, -but generally 
without any vein form whatever. There are ores in the lower: 
mercury than the ohne eso ere As much oslo is fated 
in the St. Barbara mine as in all the other quicksilver forma- 
ons of Peru. The arsenical mercury ores were rejected by the 
ers, because of the effects of the arsenic in the furnaces. 
Sulphate of barytes both in — and closely mingled with 
siliceous grains occurs in the min ge quantities of iron 
pyrites are also found, much of ohials might no Sout ‘a 
ably work 
