CHLORINE AS A GOLD SOLVENT.

Grey River Argus, Volume IX, Issue 686, 11 June 1870, Page 1 (Supplement)

CHLORINE AS A GOLD SOLVENT.

.We append an interesting ietter addressed to the editor of the Ballarat Star, from Mr R. M. Serjeant, a gentleman well qualified to speak on the subject of which he treats : — Sir, — In your last issue of this day it is stated,,'/ chlorine in almost inexhaustible quantity has been discovered near Geelong." If this statement be correct then the difficulties hitherto experienced in extracting the whole of the gold from this matrix is Bolved, and the clumsy, expensive aud inefficient process of amalgamation with mercury will soon bo among the things of the past, for chlorine is a perfect solvent of gold, and its application for such purpose has been successfully used sn the gold mines of Hungary for many years. Without pretending to set myself as an authority in chemistry, I may be permitted to refer to the elegant little process of dissolving gold in aqua regia (one part nitric to two parts hydro-chlyric acid.) The admixture of these two acids generates chlorine, which chlorine is the _agfint -that dissolves the gold. Only a

few months since ono of the officials in the Sydney Mint discovered a process of toughening gold and rendering it free from all foreign substances, superior to any other known process, and for which discovery the Sydney Government paid him L2OOO. The agent employed in this precis? -is chlorine gas, and, like many other valuable discoveries; is of a remarkably simple and economic character. If equal parts of the black oxide of manganese and common salt to be mixed in a retort with sufficient oil of vitriol to make a paste, the application of heat generates chlorine gas, which may be collected in bottles in a pneumatic trough. The Sydney Mint official, however, appears to have passed the gas direct from the retort into the crucible full of molten gold by means of a clay tube, and thus attained his object of toughening and purifying the gold. Chlorine gas readily dissolves in water, and it is in this form that it has been employed by the gold miners of Hungary. The manner in which the discovery near Geelong may be utilized by the gold miners of Australia must be left to practical chemists to determine.