NATIVE PLATINA. 5 namenting porcelain ; and although when burnt in and burnished, it has nearly the same colour as silver, yet it is not, like it, liable to be tarnished by sulphureous ef fluvia, or to be affected by alterations of the atmosphere. The platina used for these purposes is repeatedly melted with arsenic; without its aid, we could only have ob tained it in very small masses, owing to the intense heat required for its fusion, and the small quantity fused. Observations. 1. The name Platina is originally Spanish, and is the diminutive of plata, silver, probably on account of its re semblance to it in colour, owing to its occurring in small grains. 2. It is distinguished from Silver, by its colour, exter nal shape, greater hardness, and specific gravity. 3. It is chemically distinguished from Silver, by its infusibility without addition, and its insolubility in nitric acid. 4. In the cabinet of the Academy of Bergaria in Bis cay, there is said to be a mass of platina, the size of a pigeon's egg *. Humboldt has lately presented the King of Prussia with a mass which is still larger, and which weighs 1088.8 grains, and has a specific gravity of 18.947, according to Professor Tralles. A3 2. Palladium. * Mr Ataman, a Mexican gentleman, informs me, that there is no spe* cimen of platina of the size mentioned in the text, in the Academy of Ber* garia.