REPORTS FROM THE SECTIONS: ; 259 
quantity of this metal has been lost from the cause already stated. 
Tt may be of some assistance to pros pectors to note that silver 
deposits are generally found amongst the ancient stratified rocks, 
as micaceous, quartzose, and clay slates, limestone, and sandstone 
near granite. All the great silver deposits of the world, as at 
the Comstock in Nevada, pernseeger and others in Mexico, 
Carpathia, in Europe, and in Bolivia, are found acc 
a recent dioritic porphyry (the petite Hg of Richthofen), probably 
tertiary or post-tertiary age, though resembling ancient rocks. 
generally absent. The rock contains much iron and is pip at 
by w eathering, becoming stained red with the oxide. 
The silver ore is meehy found in quartz, and the surface of 
the veins is usually drusy and much stained with oxide of iron, 
whilst the quartz is often very friable. 
