486 SMITHSONIAN" MISCELLANEOUS COLLECTIONS 



The antecedent atomic weio;hts are — 



Ag = 107.880, ± .00029 

 CI = 35.4584. ± .0002 

 Br = 79.9197, ± .0003 



VOL. 54 



Hence, 



From ratio 13 Pt = 194.663, ± .0199 



" 7 195.014, ± .0160 



" 1 195.123, ± .0203 



" 4 195.169, ± .0050 



" 10 195.212, ± .0112 



" 11 195.215, ± .0142 



" 5 195.216, ± .0081 



" 8 195.216, ± .0356 



" 17 195.225, ±: .0037 



" 2 195.227, ± .0221 



" 19 195.227, ± .0070 



" 9 195.229, ± .0203 



" 12 195.231, ± .0130 



" 18 195.231. ± .0045 



" 14 195.236, ± .0951 



" 6 195.248, ± .0074 



" 3 195.252, ± .0276 



" 16 195.416, ± .0330 



" 15 195.785, ± .1622 



General mean, Pt = 195.210, 



.0020 



