Occurs in nature alloyed with osmium as osmiridium or iridosmine, which is “ rather abundant in the auriferous beach sands of Northern California” (Dana). It
Platinum occurs in nature in alluvial deposits associated with gold and some rare metals, generally in fine metallic grains, and, occasionally, in nuggets. It is a
Small buttons, such as are got in assaying most gold ores, are placed on a polished steel anvil and flattened by one or two blows with a
The method of separating the gold from the silver in gold-silver alloys by boiling with nitric acid does not act equally well in all cases.
The determination of the quantity of a cyanide is made by finding how much silver nitrate is required to convert the whole of the cyanide
The thin sheet of metal is dropped into hot dilute nitric acid and boiled for five or six minutes after the brisk action of the
Large quantities of lead carrying gold and silver are sold to refiners in bars weighing about 100 lbs. each. The assay of these alloys presents
The use of the microscope also is a real advantage in estimating the weights of minute buttons of gold where there is no undue risk
The process is as follows:—The cupels, which should have been made some time before and stored in a dry place, are first cleaned by gentle
The chief ore of lead is galena, a sulphide of lead, common in most mining districts, and frequently associated with blende and copper-pyrites. It always