204. The process of gold extraction known as Plattner's chlorination process, which is that described in the text, originated in Europe, and was first introduced here by G. F. Deetken, M. E., at Grass Valley, in Nevada County.

In 1866, Mr. Deetken having removed from Grass Valley, the operators who succeeded him were suddenly confronted by a difficulty in the treatment of the concentrations from the Eureka mine, which all at once developed an amazing capacity for absorbing chlorine, so that the application of Plattner's process to them was no longer profitable. The writer, happening to visit Grass Valley in that year, was applied to for a remedy for the difficulty, which, not being aware of the cause, nor having facilities for investigation, he was not able to supply; but the matter being made public through the medium of the Mining and Scientific Press, it arrested the attention of Mr. Deetken, who at once repaired to the spot, and, with his well known skill, and professional sagacity, detected the cause of the difficulty and applied the remedy.

The trouble was occasioned by the presence of a magnesian compound in the concentrated sulphurets. By the addition of a small quantity of salt to the roasting mass, this substance was converted into magnesium chloride in the furnace, much more cheaply than it could be done by means of chlorine in the vats. The gold was then chloridized in the usual manner. The use of salt in the furnace for this purpose was, so far as is known to the writer, original with Mr. Deetken, being quite distinct from its use for the purpose of chlori-dizing silver, when present in the ore. To this gentleman we also owe the demonstration of the possibility of conducting the process in wooden vessels.