VOL. XLVIII.] PHILOSOPHICAL TRANSACTIONS. 507 



of platina to the principal substances which act on metallic bodies; and 

 shown that it is a simple metal, of a particular kind, essentially distinct from all 

 those hitherto known, though possessed of some properties generally supposed 

 peculiar to gold. Many of its distinguishing characters have been already pointed 

 out; others will result from combining it with the several metals; with each of 

 which, notwithstanding its resistance to the most intense fires by itself, or with 

 unmetallic additions, it melts perfectly; occasioning remarkable alterations in 

 their colour, texture, and hardness. 



Art. 1. — Platina with Tin. 1 . Equal parts of platina and pure tin were injected 

 into a mixture of black flux and common salt in strong fusion ; and urged with 

 a quick fire, in a good blast furnace. After a few minutes the whole appeared 

 perfectly melted; and on being instantly poured out, ran freely along a narrow 

 mould, forming a smooth ingot, nearly of the same weight with the platina and 

 tin employed. The compound proved extremely brittle, breaking easily from a 

 fall; internally it appeared of a close and smooth, though uneven surface; and 

 of a dark grey colour. By the file, or a knife, it was readily scraped into a 

 blackish dust. 



2. One part of platina and two of tin, covered with a black flux, borax, and 

 common salt, were melted in a wind furnace : the platina appeared perfectly 

 taken up by the tin, soon after the fire had been raised to a light white heat. 

 The ingot was found deficient in weight about Vf- It greatly resembled the 

 foregoing, being only a little less brittle, and of a somewhat lighter colour. 



3. One ounce of platina and 4 of tin, covered with black flux and common 

 salt, and urged with a quick fire, melted together without loss. This compound 

 yielded a little to gentle strokes of a flat hammer, but was by no means tough. 

 It broke in pieces from a rude blow, and was still readily scraped into dust by a 

 knife. The surface of the fracture was rough and granulated. 



4. One part of platina and 8 of tin, injected into a fluid mixture of black flux 

 and common salt, united, without loss, into a pretty tough compound; which 

 bore to be considerably flattened under the hammer without breaking, cut 

 smooth with a thin chissel, and shaved with a knife. Broken, it appeared of a 

 sparkling, dark coloured, coarse grained texture. 



5. One part of platina and 12 of tin, treated in the same manner, formed a 

 mixture tolerably ductile; but still of a dull, dark hue, and a rough coarse grain, 

 though somewhat less so than the preceding. 



6. A mixture of 1 part of platina and 24 of tin, proved not much stifl^er 

 than tin. The colour was whiter, and the grain finer and evener than those of 

 the preceding compositions ; though in both respects it fell considerably short of 

 pure tin. 



7. Several of these compositions, covered with black flux, vvhicli hiid been 



3x2 



