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action added alkaline alloy amalgam ammonia antimony arsenic assay bismuth blowpipe boiling brittle carbonate charcoal chemical chloric acid chloride coal colour combined composition compound condensed containing converted cooling copper crucible crystalline crystals cupel cyanide decomposed deposit dilute dissolved distilled dried employed equivalent evaporated excess filtered flame flux formed fuel furnace fused fusible fusion glass gold grains hence hydrated hydrochloric acid hydrogen hydrosulphuric acid inch insoluble Lastly latter lime litharge malleable mass melted mercury metal mixed mixture nitrate nitric acid obtained operation ordinary oxide oxide of lead oxidised oxygen palladium passing placed plate platinum porcelain portion potash potassa potassium powder precipitate produced proportion protoxide pure readily red heat reduced removed rendered reverberatory furnace salt separated sesquioxide silica silver slag soda sodium soluble solution specific gravity sulphate sulphide sulphide of ammonium sulphuric acid surface temperature throw titanic acid tube washed weight yellow zinc
Page 453 - Indian rum, ie rum and water in the proportion of one part of the former to two of the latter.
Page 203 - ... the boiling being further carried on for a short time ; after which the digester is allowed to remain at rest, in order that the gold may subside. Sometimes it may be requisite to use even a third acid. Repeated washing of the gold with boiling water is now necessary, for sulphate of silver is a very insoluble salt, and sulphate of copper, when contained in so acid a menstruum, is also somewhat so. Hence, without such washing, the gold would be liable to be contaminated with the very alloys separated...
Page 245 - Those who would view this subject scientifically should here consider, that as platina cannot be fused by the utmost heat of our furnaces, and consequently cannot be freed like other metals, from its impurities, during igneous fusion, by fluxes, nor be rendered homogeneous by liquefaction, the mechanical diffusion through water should here be made to answer, as far as may be...
Page 362 - ... used as a source of sulphur in the manufacture of sulphuric acid; but, as it commonly contains traces of arsenic, such acid is very liable to be contaminated with the latter. It is also a large source of the copperas of commerce, or impure sulphate of iron.
Page 432 - ... to the platinum, returns by the connecting wire to the zinc ; and further, the deflection of the needle to the right, or to the left, indicates most certainly which end of the wire is connected with the zinc, and which with the platinum plate.* Thus it appears that the chemical action commenced at the zinc is accompanied by a current of electricity, whereby, in the particles of...
Page 268 - Is formed when hydrochloric acid or a soluble chloride is added to any solution of a salt of protoxide of lead.
Page 202 - ... being formed, which is then sold as " blue liquor." The use of sulphuric acid for the operation is preferred at many refineries, particularly on the Continent. It is more economical, for not only is the acid itself much cheaper, but the resulting gold is more thoroughly freed from silver ; indeed, it is said that gold which has been refined by nitric acid may subsequently have more silver separated from it by the sulphuric acid process.
Page 389 - I that it becomes malleable. Considerable evolution of heat attends the heating of these together; and Clarke states, that if tin and platinum foils be rolled together and heated before the blowpipe, combination takes place explosively. Tin forms a very brittle alloy with palladium. The alloys of tin with lead constitute pewter, and also an important class called
Page 245 - And since platina cannot be fused by the utmost heat of our furnaces, and consequently cannot be freed, like other metals, from its impurities during igneous fusion by fluxes, nor be rendered homogeneous by liquefaction, the mechanical diffusion through water should here be made to answer, as far as may be, the purposes of melting, in allowing earthy matters to come to the surface by their...
Page 245 - By repeated washing, shaking, and decanting, the finer parts of the gray powder of platina may be obtained as pure* as other metals are rendered by the various processes of ordinary metallurgy; and if now poured over, and allowed to subside in a clean basin, a uniform mud or pulp will be obtained, ready for the further process of casting.