80 ATOMIC WEIGHT DETERMINATIONS. 



E. Turner : 5Jf.9 (0 = 16). 



Turner analyzed the carbonate in an apparatus similar to 

 Bunsen's. He found 34.72 per cent, carbon di-oxide and 

 8.427 water. For C = 6, he calculates Mn = 28.024. By 

 dissolving the protoxide in sulphuric acid, evaporating and 

 heating to redness, he found 9 oxide = 19.01 sulphate. If 

 S = 16, this gives Mn = 27.96. A second experiment gave 

 27.93. From 12.47 Mn chloride he obtained 28.42 argentic 

 chloride. [If CI = 35.5, Ag = 108 ; this gives Mn = 54.9.] 

 The carbonate v^^as obtained by precipitation with potassium 

 carbonate. The protoxide was obtained by reduction of 

 higher oxides in hydrogen. The chloride was melted in a 

 current of HCl gas. [Edinh. Trans., 11, 1831, 143.) 



J. J. Berzelius: S5.S4, (0 = 16); 345.9 (0 = 100). 



Berzelius repeated Turner's experiments, taking larger 

 quantities. From the chloride he got from 345.84 to .96 ; 

 from the sulphate from 346.03 to .29. Ag = 1351.607; 01 

 = 221.325 ; S = 201.165. {Berzelius' Jahresbericht, 9, 1830, 

 136.) 



J. J. Berzelius: 55.14. (0 = 16); 344.684 (0 = 100). 



In his Lehrbuch he apparently takes the analyses of the 

 chloride above cited, recalculated for 01 = 221.64 ; Ag = 

 1349.66. {Lehrbuch, 3, 1224.) 



E. Brandes: 57.06 (O = 16); 356.602 (0 = 100). 



Determined by analysis of crystallized chloride. The 

 chlorine was determined by precipitation with silver. The 

 Mn was precipitated as carbonate, and converted into oxide 

 by heat. The water was determined by difference, and the 

 composition of the oxide was assumed to be as given by 

 Berzelius, (!) whose values for Ag and 01 were also taken. 

 {Poggend. Ann., 22, 1831, 256.) 



K von Hauer : 54.98 (0 = 16); 343.632 (O = 100). 



Determined by nine experiments on the reduction of the 

 sulphate to sulphide by heating the salt in a current of 

 hydrogen sulphide. The reduction was performed in a 

 porcelain tube enclosed in a charcoal fire. ISTuraber, mean ; 

 extreme difference, 0.34, for O = 16. The sulphate was 

 prepared from a pyrolusite containing only silica, iron, and 

 barium. It was reduced to protoxide, dissolved in sulphu- 

 ric acid, oxidized with nitric acid, precipitated with oxalic 



