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While solution is going on for a time in the vat a the electrolytic vat k is disconnected from it by closing the valves w and y, but when the solution has for some time gone on in a the valves w and y are opened, and a valve .* in the pipe dis closed. The fluid carrying the mineral matter is thus caused to circulate not only through a, but also through k from the distributing-pipes o downward past the electrodes to the suction of the pump, and thence as before through a, and so on. When the vat k is of metal its interior should be enamelled or otherwise coated to prevent electrochemical action on it. Instead of employing electrolysis as above described, for which a current of electricity is necessary, the metal may be deposited from the solution upon zinc shavings, in the known manner. When this method of depositing is adopted it is only necessary to remove the electrodes from the electrolytic vat and charge it with zinc shavings; all the connections to the dissolving-vat remain unchanged. Instead of employing a single dissolving-vat several of these may be arranged to operate in succession with one electrolytic vat or several of these. Each of the dissolving-vats may deliver to the next in order solution with a less quantity of solid matter and the liquid from the last of these vats, whence after deposit of the precious metal the liquid may be returned to the first of the dissolving-vats. 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. In apparatus for extracting precious metals from minerals containing them the combination of a dissolving-vat with a circulating pump, or its equivalent, with suction- and discharge-pipes and a valved discharge, substantially as and for the purpose set forth. 2. In combination with the dissolving-vat above referred to amalgamating-plates attached to its sloping sides, substantially as described. 3. In combination with a dissolving-vat such as is above referred to a nozzle to the dischargepipe having helical passages, substantially as and for the purpose set forth. 4. In combination with the dissolving-vat above referred to an electrolytic vat with connecting pipes and valves and with electrodes arranged therein, substantially as described. 5. The herein-described method of treating minerals containing precious metals for extraction cf the metals therefrom by causing the crushed mineral mixed with solvent solution to circulate or pass through a dissolving-vat or several of these which may contain amalgamating-plates, and also through an electrolytic vat, or other depositing-vat. Dated this 22nd day of October, 1897. Beda Beckhk.

Improved Apparatus for saving Fine Gold. I, George Henry Oatway, 31, Moray Place, Dunedin, New Zealand, merchant, do hereby declare my invention for " Improved Apparatus for saving Fine Gold," and in what manner the same is to be performed, to be particularly described and ascertained in and by the following statement :— The object of this invention is to produce an apparatus that will arrest any fine gold that passes through it, and it consists of a combination in any description of enclosed box, chamber, or flue of straight, fluted, or curved metal plates having plain, chequered, or roughened prepared goldsaving surfaces (the sides of the box will usually be lined in a similar manner, and where required may be used so lined and without plates) in either case for the purpose of reclaiming the light or float gold which sometimes escapes to the dump in the tailings or tail-water of a dredge, hydraulic elevator, or ground-sluice. These plates or lining are preferably placed at an inclined plane to the current, and far enou°h apart to discount choking, whilst (when using the plates) dividing the auriferous wash- and tail-water to be dealt with into as many separate streams or slices as may be expedient. The passage through between the plates is either a parallel one without break or angle, or taper, preferably narrowing towards the lower or outlet end, and generally widening the other way, so that the same area is maintained throughout. Where curved or fluted plates are used the same method would be adopted; the streams being compressed one way and forced out laterally into a fan shape tend to facilitate contact of the gold and the saving surfaces of the plates or sides of the box. The auriferous material and water may thus be passed through in one stream or film, or may be split up into a number of streams or films, and in its passage through the apparatus it is confined between surfaces, whether parallel or converging, fluted, straight, or curved. A fixed, vibratory, or revolving screen, sieve, or grating, or a series of any screens, sieves, or gratings, for attachment to or for use in conjunction with the tailings-chute, or sluice-boxes, or races of a hydraulic elevator or ground-sluice, for the purpose of restraining or preventing the coarser pieces of quartz or stones travelling with the auriferous wash-and water from passing through to the prepared gold-saving plates and scouring or rubbing off.the amalgam or other preparation or material, or choking. This screen or series of screens may be fixed in the sides of the races to allow the fine wash to pass to the plates on either side or horizontally, vertically, or at any incline to the current, or in any other way, for the purpose indicated. Also the same fixed, vibratory, or revolving screen, or series of screens, sieves, or gratings, for attachment to and for use in conjunction with the tables, sluices, or other gold-saving appliances of a dredge for the purpose of receiving the auriferous wash and water at any time after its delivery from the principal revolving screen, or from the buckets or suction-pipe if no screen is used, and restraining or preventing the coarser particles travelling with such washdirt from passing between