PROOFS OF THE PROPERTIES OF TIN.

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been sufficiently ascertained by the researches of Pelletier. Inthe first amalgamation and trituration of the mercury and tin, thelatter is divided, and in some degree oxidated; when the mixtureof this amalgam with the sulphur and muriate of ammonia isheated, the muriatic acid, by a disposing affinity, enables the tinto be oxidated by decomposing the water, and this oxid combineswith the muriatic acid; the hidrogen of the water is disengagedwith the ammonia of the muriate of ammonia; this ammoniaunites with a portion of the sulphur, and forms sulphuret ofammonia, which being disengaged, causes the white fumes. Theheat being now augmented, the muriate of tin is again decom-posed, the oxid of the metal attracting a portion of the sulphur,and forming the aurum musivum. Such is the aetiology of thatcomplicated process given by Pelletier.

Aurum musivum is employed to give a beautiful colour tobronze, and to excite the strength of electrical machines. It isused by japanners, and for many articles intended to have theappearance of metallic gold.

Experiment III.

Tin decomposes nitric acid with great rapidity, and formsammonia ly the addition of an alcali.

Moisten some powdered tin with concentrated nitric acid, andwhen the red fumes have ceased to arise, add some solution ofpotash. A strong smell of ammonia will be immediately pro-duced.

Rationale. ..In this case the tin decomposes both the nitricacid and the water : the hidrogen of the latter, and the nitrogenof the former being presented to each other in their nascent state,by the addition of the alcali, unite and form ammonia which isdisengaged.

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