200 M. Stas on the Determination of Atomic Weights. 



persistently retains some sulphuric acid, and is much more 

 difficult to wash, especially if it cakes together. It is intro- 

 duced into a flask closed by a stopper, which by a suitable 

 arrangement is set in a circular and wavy motion. The clearing 

 of the liquid was effected by passing steam into it and not into 

 the chloride, by which caking is prevented. The complete 

 washing out lasted seven days, the flask being kept warm day 

 and night. All the wash-waters, after being allowed to stand, 

 were filtered through a fine filter; all the vessels were rinsed 

 out with solution of cyanide of ammonium, and the latter 

 evaporated with the addition of hydrochloric acid. In one ex- 

 periment the chloride of silver obtained was fused in a current 

 of hydrochloric acid gas. No liberation of sulphuric acid could 

 be perceived, nor was there any alteration in the weight of the 

 chloride of silver. In one experiment 138 grms., and in another 

 259 grms. of chlorate of silver were used. The experiments 

 gave, in 100 parts of chlorate of silver, 



Mean. 

 Ag CI . 74-919 74922 74-9205 



. . 25-081 25-078 25-0795 



100-000 100-000 1000000 



Hence the atomic weight of AgCl= 143*395, that of silver 

 = 107*937, and that of chlorine=5'458, from the synthesis 

 of chloride of silver. 



The final result of this set of determinations of the atomic 

 weights is as follows (9 = 16) : — 



Silver. 



From the composition of Agl and AgIG 3 = 107*928 



AgBr „ AgBrO 3 = 107*921 



AgCl „ AgCIO 3 = 107*937 



Mean . = 107*929 



Stasis earlier experiments = 107*931 



Marignac = 107*928 



Chlorine. 



From the analysis of Ag CI and Ag CI O 3 . = 35*458 



Stasis earlier experiments = 35*460 



Marignac = 35*455 



35*457 

 Bromine. 

 Stasis new experiments ....... = 79*940 



Marignac = 79*945 



Marignac * . . = 79-968 



79951 



