104 



RESEARCHES UPON ATOMIC WEIGHTS. 



RESULTS. 

 Atomic Weight OF Iodine. Series IV. AglrAgCl. 



No. of 

 analysis. 



20 

 21 

 22 

 23 

 24 



Weight of 

 silver iodide 

 in vacuum. 



mg. 



9.26856 



6.72058 



11.31822 



10.07026 



13.49224 



Weight of 



silver chloride 



in vacuum. 



gm. 

 S.65786 

 4.10257 

 6.90910 



6.14753 

 8.23645 



Ratio. 

 Agl : AgCl. 



I.638174 

 I.638139 

 I.638161 

 1.638099 

 I.638114 



Atomic weight 



of iodine. 



Ag:= 107. S80. 



Cl = 35-457 



126.931 

 126.926 

 126.929 

 126.920 

 126.922 



Average i. 638137 



126.925 



At the time when these experiments were performed, Richards and Wells had 

 not completed their research upon the atomic weights of sodium and chlorine, 

 so that, although these investigators had found that Stas's determination of the 

 atomic weight of chlorine had yielded too low results, the magnitude of his error 

 was still uncertain. Using a value for chlorine intermediate between Stas's and 

 Richards and Wells's final result, the above five experiments in Series IV 

 appeared to agree almost exactly with the results of the first three series of 

 experiments, and accordingly all four series were published. Not long afterwards 

 Richards and Wells's research was completed. Using their final result for 

 the atomic weight of chlorine, 35.457 (Ag = 107.880), as has been done in this 

 paper. Series IV gives a result 0.0 1 unit higher than the average of Series II and 

 III. The desirability of further investigation of the atomic weight of iodine 

 was evident and new experiments were accordingly begun. 



