MINERALOGY. 179 



its metallic form, and in form of a calx or 



glafs. 



3. It dees not amalgamate with quickfilver 

 by itfelf, but only by means of the acid of 

 common fait after a long trituration. This 

 metal is therefore really feparated from 

 geld by amalgamation, at thofe places 

 where it is found •, and without this qua- 

 lity, it would be very difficult to feparate 

 it. 



4. It is harder and lefs coherent than gold, 



£. It is heavier than gold ; and therefore the 

 heavier! of all bodies hitherto diicovered : 

 For though the lpecific gravity of platina, 

 in the hydroflatical experiments made by 

 i)r. Lewis, is found to be to water only as 

 17, 00 to iccc: yet, when melted with 

 ier certain metals, its lpecific gravity 

 has, by an exact calculation, beer, found 

 to be conHderably augmented, e r en fo 

 much as to 22,000. 



6. Difloived in aqua regia, and precipitated 

 with tin, or with a folution of that metal, 

 it yields no purpura mineralis. 



Except thefe, this metal has the fame 

 qualities as gold ; but it cannot, on ac- 

 count of its refracTorinefs in the fire, be 

 worked off pure on the cuppel, nor like- 

 wife can it be worked with antimony ; be- 

 caufe, before it is rendered perfectly pure, 

 it cools, grows hard, and retains always 

 fome part of the added metals. It is 

 brought to us only in its native ftate, in 

 fmall, irreg-ular, rugged grains : and it is 

 yet uncertain whether it is found naturally 

 mineraiifed. The Platina is brought to 



N 2 Europe 



