SULPHUR. 115 



H. Struve: 32.002 (0 = 16). 



Determined by six experiments on the reduction of a 

 known weight of argentic sulphate in a current of hydro- 

 gen. The number is the mean ; extreme difference, 0.146. 

 Ag = 108. The sulphate was prepared by precipitating 

 the nitrate with an excess of sulphuric acid, and drying at 

 a high temperature. (Liebig's Ann., SO, 1851, 20S ; Berze- 

 lius' Jahresbericht, 30, 20.) 



J. Dumas : 32.0196 (0 = 16). 



Determined by five experiments on the combustion of 

 silver in sulphur vapor. The number is the mean ; ex- 

 treme difference, 0.054. Ag = 108. The sulphur was 

 purified by repeated distillation. The silver was heated to 

 redness in a current of sulphur vapor, the excess of sulphur 

 being afterwards distilled ofi'in a current of carbon di-oxide. 

 {Annal de Chim. et de Phys., (3,) 55, 1859, 147.) 



J. S. Stas : 32.0742 [?] (0 = 16). 



According to the mean of six analyses of argentic sul- 

 phate by decomposition in a current of hydrogen at as low 

 a temperature as possible, 100 sulphate yield 69.203 [more 

 exactly 69.20317] silver; extreme difference, 0.012. Five 

 syntheses of the sulphide, performed by heating silver in a 

 current of sulphur vapor or hydrogen disulphide, showed 

 that 100 silver = 114.8522 sulphide ; extreme difference, 

 0.005. By comparing these figures, which are for vacuum, 

 Stas deduces S = 32.0742 ; Ag = 107.920. [There seems 

 to be a trifling error in this calculation. The weighings 

 seem to be correct, for the means correspond to the de- 

 tails given. As given, the numbers indicate S = 32.058; 

 Ag = 107.926. The latter is almost identical with Stas's 

 mean value, 107.930.] The sulphate was prepared by the 

 action of sulphuric acid on argentic nitrate, or by solution 

 of silver in sulphuric acid. The salt was heated above the 

 boiling point of sulphuric acid. [Stas, [Inters, iiber Chem. 

 Prop., Leipzig, 1867.) 



