5. _Platina and tin._ Equal parts of platina and tin unite by fusion, and form a dark coloured brittle alloy. But when the platina falls short ⁷/₉ of the alloy, the ductility and whiteness proportionally increase. _ibid._ 6. _Platina and lead._ These two metals may be combined in various proportions by heat; but the compounds are not stable, part of the platina falling down, when the alloy is subsequently melted. _ibid._ 7. _Platina and zinc._ Platina may be combined with zinc, by being exposed to the fumes of the metal as reduced from its ore. Three parts of platina become four of alloy. It is hard, brittle, of a blueish white colour, and easily fusible. _ibid._ 8. _Platina and bismuth._ Platina and bismuth combine readily in a high temperature in almost any proportions. The alloys are brittle. _ibid._ 9. _Platina and antimony._ Platina easily combines with antimony by heat. The alloy is brittle. _ibid._ 10. _Platina and arsenic._ When white oxide of arsenic is projected upon strongly heated platina, an imperfect union takes place with a partial fusion of the mass; it is brittle, of a greyish colour and a loose granulated texture. _Lewis._ _Alloys of Silver with other Metals._ 1. _Silver with mercury._ See amalgams. 2. _Silver with copper._ Silver and copper are easily alloyed in any proportion by fusion. The compound is harder than silver, and retains its white colour when the copper is half of the alloy or more.--The silver coin is a compound of 12⅓ silver and 1 copper, which nearly corresponds to 8 atoms of silver and 1 of copper. The hardest alloy is said to be when 5 silver unite to 1 copper; that is, 3 atoms of silver and 1 of copper. 3. _Silver with iron._ The alloys of silver and iron have not been very minutely examined. The two metals are said to unite by fusion, but the iron still retains its magnetism. The alloy is of a white colour, hard and ductile. When kept in fusion for some time the two metals separate, but not entirely. These circumstances shew the affinity between silver and iron to be weak. 4. _Silver with tin._ Silver and tin form a hard brittle alloy, which is of little if any use. The modifications arising from various proportions have not been particularly investigated. 5. _Silver and lead._ Silver and lead unite in any proportion and form a brittle alloy of a lead colour. The union is not very intimate; for when urged by heat the lead parts from the silver, as in the process of cupellation. 6. _Silver and zinc._ These two unite and form a brittle alloy of a blueish white colour. The proportions have not been particularly noticed. 7. _Silver and bismuth._ Silver and bismuth readily unite by heat. The alloy is brittle and its colour inclines to that of bismuth. 8. _Silver and antimony._ These metals unite by fusion and form a brittle alloy, which does not seem possessed of any remarkable properties.