PLATINUM. 449 



the experiment from which Berzelius deduced 

 the proportion of oxygen in the peroxide, I 

 rather think it surprizing that the coincidence is 

 so great as it is. Javal actually analyzed the 

 peroxide of gold, by heating it in a glass tube, 

 and collecting the oxygen gas. He estimates 

 the composition at gold 100, oxygen 11*909 > 

 but his estimate was founded on the specific gra- 

 vity of oxygen gas as determined by Berzelius 

 and Dulong, which I have shown in a former 

 chapter to be too low. When we correct his es- 

 timate, the proportion of oxygen united to 100 

 gold turns out to be 12-0008, a number which 

 I am persuaded is almost exact.* 



SECT. II. 



OF THE ATOMIC WEIGHT OF PLATINUM. 



PLATINUM dissolves, as every body knows, in 

 strong nitromuriatic acid with effervescence. The 

 solution has a dark brown colour, and is very as- 

 tringent and corrosive. When concentrated by 

 evaporation it does not crystallize, but forms a 

 dark coloured dirty looking matter, not easily 



* 1 have some suspicion that the true atomic weight of gold may ulti- 

 mately turn out only 12-5 instead of 25. If that be the case, the triple salt 

 analyzed in this section would be a compound of 2 atoms chloride of gold 

 and 1 atom chloride of sodium. We have not data, at present, to deter- 

 mine this point with certainty. 



Vor, I. F f 



