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" Mercury, having a greater affinity for metals than for stone, condenses in preference on the gold present, and thus amalgamates the metallic particles and renders them eminently susceptible of solution when they reach the bath of hot mercury. In the old process the mercury could not be used at a temperature above that of the water which covers it. "The new process will treat pyrites and other intractable ores almost as effectually as it will free-milling quartz. In the present case it has saved about 82 per cent, of the total gold present in an ore from which stampers only obtained an average of 82J per cent, of the gold." Newbcry-Vautin Process of Chlorination. A new method of chlorination and leaching has recently been brought into use by Messrs. Cosmo Newbery and Claude Vautin, of Melbourne, for the treatment of roasted auriferous sulphurets. The process, however, has not yet been sufficiently in use to fully bear out its practical utility, which the inventors claim to have discovered, for treating auriferous and argentiferous ores in a satisfactory and economical manner ; nevertheless there is a certain guarantee connected with its success when a scientist such as Mr. Newbery is connected with it. Even should the details of the plant be defective the principle is correct; and should there be any defects in any portion of its details these will soon be remedied. The greatest feature in the process is that chlorination is produced in a far shorter time than by the old process, and the cost of treatment is not one-half the former expense. The latter is the great desideratum in order to be able to manipulate poor ores. The old system requires the ore to be first damped, an operation requiring not only great care, but also skill, as it must not be too wet nor too dry if good results are to be produced. It has to be sifted into a vat, and chlorine gas has to permeate, through a filter-bottom, on which the ore rests, and also through the whole body of the ore, which requires from twenty-four to forty-eight hours to produce effective chlorination. It is well known that chlorine gas is of a very poisonous character, and in treating under the old system the lid has to bo removed, when the poisonous fumes escape into the building, and are very injurious to the workmen. The process perfected by Messrs. Newbery and Vautin is said to overcome all these obstacles. In the new process Messrs. Newbery and Vautin claim that the improvements are of such a character that not only are the mechanical difficulties of the old method overcome, but the chemical reactions are greatly accelerated, the cost reduced from about £1 10s. to 12s. per ton, and the loss of gold practically nothing ; that the old slow, costly, and cumbersome process has been converted into a rapid, economic, and effective means of extracting gold from auriferous pyrites, refractory ore, tailings, &c, from which, when necessary, antimony, sulphur, arsenic, &c, have been removed by proper calcination. The plan herewith annexed will enable any one more readily to understand ths principle of this process from the following description : The material to bo treated is taken from the calciningfurnace in trucks, which are hoisted up for a certain distance to allow the ore to pass through the various processes of treatment with the minimum amount of hand-labour. The ore is deposited in the hopper A, immediately over the chlorinator B, which is a rotating-barrel constructed of such material and in such a manner that chlorine has little or no effect on it, and strong enough to withstand an internal pressure of 601b. to the square inch. The chlorinator Bis charged with from 20cwt. to 30cwt. of ore from the hopper A by a chute from the hopper to the man-hole ; a given quantity of water, chlorine, or chlorine-producing chemicals is then added ; the man-hole is then securely placed in position, and the vessel is then perfectly air-tight. A pipe leading from the air-pump C is connected with a valve on the chlorinator, which is opened, and an air-pressure produced as required or found necessary, depending on the coarseness of the gold. The effect of this air-pressure will be explained further on. The valve is then closed, and the connection with the air-pump broken. The vessel, with its contents, under pressure, is caused to revolve for one hour, when it is stopped, and a pipe connected with the valve which leads into a closed vessel or vessels D, in which there is lime or soda-water; the vessels D are connected with a vacuum-pump of special construction, so that when the valve on the chlorinator A is opened, any chlorine that may exist in the form of gas is drawn into the lime or sodawater in D and absorbed. By this means the workmen are prevented from inhaling any chlorine gas, which would be the case if the surplus gas was not withdrawn before the chlorinator was opened. After a few minutes the man-hole door is removed and the vessel again put in motion, when the contents are discharged into the vessel E, called the solution-separator or filter, which consists of a lead-lined iron vat with false bottom, and connected with the vacuum-pump G by the pipe F. Immediately the contents of the chlorinator are deposited in the solution-separator, the communication between the vacuum-pump and filter is opened, and the solution of goldchloride rapidly withdrawn from the ore and deposited in the holder H. Water is continually added to the surface of the ore in the filter, and the solution from it tested from time to time; and when free from gold the connection with the vacuum-pump is broken, and the filter tipped up, causing the waste ore or tailings to fall into the truck, when they are run out on to the tailingsheap. The removal of the gold-solution and washing of the ore occupies, with ordinary sands, about one hour, no matter how fine. When large quantities of slime are to be treated extra filters must be provided. The solution of gold in the holder H is then allowed to flow through charcoal in vessel J, during which passage the chloride of gold is decomposed, and the gold deposited on and in the charcoal, which, when fully charged, is burnt, and the ashes fused with borax in a crucible, and the gold obtained. In places where water is scarce the liquid from J can be used over and over again with economy, as it becomes charged with hydrochloric acid, which assists in liberating chlorine in the chlorinator. It can be pumped up to the cistern X for further use. The lime or sodawater in the vessels D can also be used to produce chlorino for fresh charges of ore after it