ATOMIC WEIGHTS 



481 



Mean, 45.240, 90.486, 112.66, 225.34, 



±.0016 ±.0026 ±.00.30 ±.0047 



Pt = 195.22 195.23 195.20 195.24 



For the first of these ratios, the percentage of Pt in Iv.PtClo, there 

 are previous determinations. The three series combine tlius : 



Seubert 40.107, ± .0050 



Halberstadt 40.098, ± .0031 



Archibald 40.154, ± .0009 



General mean 40.1484, ± .00085 



Similarly, the ratio 4AgCl : K,PtClo, as determined by Senbcrt, may 

 be combined with Archibald's series. Better still tlic two series may be 

 reduced to uniform typo with Archibald's ratio for 2.\o('l. and given 



