38 Assaying. 
heat for about forty minutes, or at least until all action 
of the charge has ceased. Then pour into the moulds, 
let cool, detach lead button, hammer into a cube and 
cupel at a bright red heat until all the lead is gone and 
the remaining gold and silver globule brightens; now 
brush, flatten and weigh, calling the weight of button 
gold and silver two ounces for each milligramme it 
weighs ; note the weight, say it = 20 ozs. 
NOTEH.—If the button does not contain at least 
twice as much silver as gold, before trying to part, that 
amount of pure silver should be fused with it. 
With dilute nitric acid, in a small porcelain cap- 
sula, or crucible, dissolve the button over a spirit lamp. 
The gold falls to the bottom as a dark scale or powder; 
renew the acid and finely wash with water, pour off the 
water and remove the last drop with a piece of clean 
blotting paper, dry the crucible, with its gold contents, 
very thoroughly, cover and transfer the crucible or cap- 
sula to the heated muffle for a few minutes, then let cool 
and weigh as metallic gold, say this weight = 1.65 ozs. 
Then 20 ozs.—1.65 ozs.=18.35 ozs.; that is, there are 
18.35 ozs. of silver to each ton of 2,000 pounds and 1.65 
ozs. of gold. Taking gold at $20 per oz. and silver at 
65c per oz., we have for the assay: Gold $33.00 and 
silver $11.93, or a total value of $44.93 per ton of ore. 
LEAD. 
Crucible Process for the Assay of Lead Ores.—In 
case of sulphides, such as galena, pyrite, etc., insert in 
the crucible with the charge three iron nails (eight- 
penny), points down. These should be removed rapidly, 
but carefully, after the fusion is complete. Pass the ore 
through an eighty mesh sieve and weigh as below. 
