268 Gooch and Austin — Oxidation of Manganese. 



These results show plainly, that if the precautions to which 

 attention has been directed are taken, viz : dilution of the solu- 

 tion and heating to 80° C, presence of zinc sulphate, and 

 (most essential of all) the almost complete neutralization of free 

 acid before the addition of the potassium permanganate, the 

 manganese dioxide precipitated by the chlorate process from 

 pure manganous nitrate may subsequently, after reduction, be 

 brought by the permanganate treatment so nearly to the full 

 degree of oxidation represented by the symbol Mn0 2 , that the 

 amount of manganese originally treated may be calculated 

 with a very fair degree of accuracy from the oxygen value of 

 three-fifths of the oxide found. We do not recommend 

 this procedure as a rapid analytical method ; our purpose is 

 accomplished when the fact is brought plainly to view that the 

 oxide precipitated by the chlorate process is not the dioxide, 

 but that it may be made such by subsequent treatment. 



