174 Dr TURNER'S Chemical Examination of Manganese. 



In order to ascertain the quantity of baryta, 32-13 grains were 

 dissolved in muriatic acid ; and after separating a small portion 

 of silica, which amounted to 0*953 per cent, I precipitated the 

 baryta by means of the sulphate of soda. The insoluble sul- 

 phate, after exposure to a red heat, weighed 8*1 13 grains, equiva- 

 lent to 5*363 grains, or 16*69 per cent of pure baryta. 



100 parts of the oxide are accordingly resolved into 



Red oxide 70*967 



Oxygen 7'260 



Baryta ...... 16*690 



Silica 0-953 



Water 4*130 



100*000 



\ 



This mineral was analyzed some years ago by VAUQUELIN 

 and DOLOMIEU ; but the numbers which they have mentioned, 

 owing to the insufficient mode of analysis employed at that time, 

 are not entitled to any confidence. (Journal des Mines IX. 



778.) 



