PROPERTIES OF MANGANESE.

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PROPERTIES OF MANGANESE.

Manganese is of a whitish grey colour. Its fracture isgranulated, irregular, and uneven. It is of a metallic brilliancy,which it, however, soon loses in the air. Its specific gravityis about 0.85O. It is very hard, and extremely brittle. It isone of the most refractory metals, and most difficult to fuse,requiring at least l0o° of Wedgwood's pyrometer. Its oxida-bility is so rapid, that exposure to the air is sufficient to renderit red, brown, black, and friable, in a very short time ; it can,therefore, only be kept under water, oil, or ardent spirit.It is ihe most combustible of all the metals. It decomposeswater by heat very rapidly, as well as the greater part of themetallic oxids. It decomposes sulphuric acid. It is soluble innitric acid. It is fusible with earths, and colours them brown,violet, or red, according to its state of oxidation. It discoloursglasses tinged by iron. It does not appear to unite with sulphur.It combines with phosphorus. It unites with gold, silver, andcopper, and renders them brittle. It unites to arsenic in closevessels, but does not enter into union with mercury. It formsthree differently coloured oxids by combining with differentportions of oxigen.

METHOD OF OBTAINING MANGANESE.

This metal is obtained by mixing the black oxid, finelypowdered, with pitch ; making it into a ball, and putting thisinto a crucible, with powdered charcoal, t - 0 of an inch thickat the sides, and ^ of an inch deep at the bottom. The emptyspace is then to be tilled with powdered charcoal; a cover is tobe luted on; and the crucible exposed, for an hour, to thestrongest heat that can be raised. Or, digest the black oxid ofmanganese repeatedly, with the addition of of sugar, innitric acid ; dilute the mixture with three times its bulk of