Art. XV. a new Method of extracting Pure Gold a Alloys 
A new Method of extracting Pure Gold from Alloys, §c. 187 
nd from Ores; by C. 'T. Jackson, U.S.G 
form of a spongy mass has been practised by me for several years, 
and no account of the process has, to my knowledge, hereto- 
fore been published. It is very useful to the chemist and to the 
manufacturer, and is more economical than any other method 
{s that I am acquainted with. 
After separating the gold from silver. by means of a mixture of 
nitric and chlorohydric acids as is usually done, the solution con- 
}: taining gold and copper is to be evaporated to small bulk and 
the excess of nitric acid is thus driven off. 
A little oxalic acid is then added and then a solution of ecar- 
bonate of potash sufficient to take up nearly all the gold in the 
state of aurite of potash is gradually added. A large quantity 
of crystallized oxalic acid is then added so as to be in great ex- 
cess and the whole is to be quickly boiled. All the gold is im- 
mediately precipitated in the form of a Peete yellow sponge 
which is absolutely pure metallic gold. All the copper.is taken 
up by the excess of oxalic acid and may be * in out. 
? Boil the sponge in pure water so long as any trace of acidity 
remains, and the gold is then to be removed from the capsule 
and dried on filtering paper. It may be pressed into rolls, bars or 
thin sheets, by pressing it moderately in paper. I have made 
several useful applications of the gold sponge thus prepared, and 
had a tooth plugged with it in October, ad to which purpose 
it is well ed. 
By moderate pressure, the spongy geld hone a solid mass 
and burnishes quite brilliantly. 
he jeweller or goldsmith will find spongy gold to be quite 
convenient when he requires it for a solder, and it is a convenient 
form of the euigan for making: an amalgam for fine gildi I 
have used it for some year soldering platina, and prefer it to 
the filings or it foil for a purpose. This method of sep- 
% arating fine gold from coarse, is very simple, and cheaper than 
the usual processes. It is, applicable in the st ag of gold 
from ores that may be treated by acids, and is vastly preferable 
t. to the method commonly used by chemists and assayers 
When making oxyd of gold for dentist’s use, the chemist will 
find that oxalic acid added to his potassic solution, will at once 
recover all the gold that is dissolved in an excess of the alkaline 
solution.* Many other applications of this very simple method 
will occur to elieditate and artisans. 
| ‘ Tue following method of obtaining pure metallic gold in the 
sence 
ae 
* Much gold is lost by the usual method of preparing the oxyd. 
2 ae 
ee he Te RON hee OF Teast Pe ee CE ene Rue men en ee mT 
