PLATINUM. 4,51 



remaining mixed with the platinum will be found 

 just as much less than 9*5 grains, as that of the 

 loss exceeds 9 grains. This gives us the cause of 

 the excessive loss ; it is owing to the volatiliza- 

 tion of a portion of that salt. 

 . The matter remaining in the crucible, when 

 the heat had been properly applied, weighed 

 21 '5 grains : water was poured upon it repeated- 

 ly, and digested on it for some time, to dissolve 

 off all the chloride of potassium. The platinum 

 being then dried, was weighed, and its weight 

 was found to amount to exactly 1 2 grains ; con- 

 sequently, the weight of the chloride of potassi- 

 um was 9*5 grains. From this analysis it appears, 

 that the triple salt is composed of 



Platinum . . . 12 



Chlorine ... 9 



Chloride of potassium . 9*5 



30-5 



But the salt is neutral 9 indicates the weight of 

 % atoms of chlorine, and 9*5 of an integrant par- 

 ticle of chloride of potassium : 1 2, therefore, 

 must either be the weight of an atom of plati- 

 num, or at least, a multiple of it. From experi- 

 ments to be stated immediately, it will be seen, 

 that 12 represents the atomic weight of platinum. 

 In the salt we find 1 atom of platinum combined 

 with 2 atoms of chlorine, constituting a bichlo- 



FfS 



