47 o Experiments on the Fujion of Platina. 



would be expofed to a greater heat. I therefore 

 defired Mr. Nowell to mix one ounce of platina 

 with half an ounce of nitre, and half an ounce of 

 glafs of phofphorus, to put the mixture on a 

 bed of charcoal in the crucible, and to keep it 

 three hours in the fire, which he did, and pro- 

 duced one mafs completely fufed, that weigh- 

 ed about one drachm, befides feveral fmaller 

 mafles. 



EXPERIMENT III. 



As I had made feveral unfuccefsful attempts 

 to melt platina by itfelf, I was refolved to try if 

 it could be done by mixing one ounce of borax 

 without any charcoal at bottom ; but after three 

 hours I found only a cohefion, not a perfeft 

 fufion : there were only fmall globules near the 

 ypper furface of the mafs. 



EXPERIMENT IV. 



I bruifed the cohering mafs of the laft expe- 

 riment, and mixed one drachm of alkali of tartar, 

 two dramchs of borax powder, and one drachm 

 of charcoal powder with it, put it on a bed of 

 charcoal powder, and continued it three hours in 

 the fire, and thus produced a perfeft fufion of 

 the whole platina ; half a drachm only of the 

 original ounce being wanting. The fpecific 

 gravity of this was taken and proved to be 

 15.353. It was fent to different polilhers and 

 lapidaries, but was fo hard, that it fpoiled their 



tools : 



