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Should the reddish-violet colour of the solutions become faint or vanish during leaching, then more of the solution must be added, but so long as the solution retains its reddish-violet colour it may be used for dissolving gold. The methods of precipitating gold are well known, and the sulphurous-acid or the ferroussulphate solution is preferred. By this invention the gold is dissolved rapidly as soon as the solution comes into contact with it. The nascent oxygen or ozone from the permanganate unites with the hydrogen of the hydrochloric acid, whilst the gold at the same time unites with the chlorine of the acid, the permanganate and the acid thus concurring to effect the solution of the gold, the reaction being an example of concurrent affinity or attraction (sometimes called "catalytic action"), and in this respect differing from the well-known chlorination processes. The reaction is therefore specific. Having now particularly described and ascertained the nature of my said invention, and in what manner the same is to be performed, I declare that what I claim is,— 1. The improved process for extracting gold from ores consisting in submitting such ores in a powdered condition to the action of a dilute solution containing hydrochloric acid, permanganate or manganate of potash, and water, substantially as described. 2. The improved process for extracting gold from ores consisting in submitting such ores in a powdered condition to the action of a dilute solution containing hydrochloric acid, permanganates or manganates of soda, and water, substantially as described. Dated this 28th day of August, 1897. W. E. Hughes, Agent for the Applicant.

An Improved Apparatus for the Treatment of Slimes and Tailings to extract the Precious Metals therefrom. I, Thomas James Denny, of 29, Great George Street, Westminster, in the County of Middlesex, engineer, do hereby declare the nature of my invention for " An Improved Apparatus for the Treatment of Slimes and Tailings to extract the Precious Metals therefrom," and in what manner the same is to be performed, to be particularly described and ascertained in and by the following statement :— This invention relates to an improved apparatus for the treatment of slimes and tailings formed in the reduction of ores to extract the precious metals therefrom. It is designed with the object of providing a simpler and more efficient plant for this purpose, cheaper both in original outlay and also in actual working-expenses than those generally in use at present; to avoid handling of the slimes when subjecting them to treatment, and to enable the treatment to be carried out continuously. It consists of an apparatus composed of a series of precipitating- or settling-vats, and mixing- or solution-chambers, each vat being provided with a pipe led upwards through the bottom of the vat, projecting internally to a point of discharge within the vat below the surface of the water, which point of discharge is variable as the density of the outflowing pulp, and which said pipe is preferably fitted with a wide or bell-shaped mouth; the water or cyanide solution, as the case may be, escapes along an overflow- or discharge-launder at the top of the vat, while at the bottom of the vat is a regulating stop-cock or valve to enable the slimes, which have been settled, to be drawn off into a cylinder or vessel into which cyanide solution is introduced with or without pressure for the solution of the gold; compressed air may also be admitted in order to agitate the mixture thoroughly. In practice I find it advantageous to have a direct connection between the vat and the mixingchamber, thus making the latter an entirely closed vessel. The apparatus will be more fully described with reference to the accompanying drawings, in which Fig. 1 is a front elevation showing arrangement of my apparatus, Fig. 2 an end sectional elevation of mixing-chamber G, and Fig. 3 a sectional plan of my apparatus. Ais a circular tank or vat, constructed of iron, wood, or other suitable material, the lower portion of which is preferably of a conical section; D is a pipe leading from the spitzkasten or spitzluten, or other discharge of slimes and tailings (or either), from a battery into the vat A, so arranged that its outlet shall be in an upward vertical direction from a point near the bottom of the vat or tank; this inlet-pipe D is preferably provided with a wide or bell-shaped mouth E to better disseminate the pulp as it flows into the vat; a funnel X is suspended, mouth downwards, in the vat, so arranged that its mouth shall be just above the mouth of the inlet-pipe D, the stem or tube J of the said funnel being of a length sufficient to project above the level of the sides of the vat. Around the inner periphery of the top of the vat Aan overflow-launder Cis arranged. At the bottom of the vat A an outlet is provided with a cock F, affixed so that the outflow may be regulated to any desired degree. The said outflow is arranged immediately above the opening G 1 in the mixing-chamber G, which chamber is constructed preferably with a sloping bottom, as shown in Fig. 1, at the lower end of which is attached the outflow-pipe D l . His a pipe leading into the said mixing-chamber G, through which cyanide solution may be introduced, while X X are inlets through which compressed air may be admitted. The outlet-pipe D 1 from the mixing-chamber G leads, in precisely the same manner as the intake-pipe D, already described, into a second vat or tank A 1 of precisely similar construction and arrangement as A. It is obvious that the series of settling-vats A and mixing-chambers G may be of any desired number according to the treatment to which it is desired to subject the pulp. The method of working the apparatus may be described as follows : — The pulp from the spitzkasten, spitzluten, or launder is fed into the vat A through the pipe D, and outflows thereinto in a gentle upward stream, the effect of which is to settle or precipitate the particles, allowing only the pure water to overflow through the launder C. This action