160 Dr TURNER'S Chemical Examination 



It is intermediate between the protoxide and peroxide, consist- 

 ing of 28 parts or one equivalent of manganese, and 12 parts or 

 one equivalent and a half of oxygen ; or rather, to be consistent 

 with the atomic theory, of two equivalents of the former to three 

 of the latter. Its elements, it is obvious, are in such proportion, 

 that it may be regarded as a compound of 44 parts or one equi- 

 valent of the peroxide, and 36 parts or one equivalent of the 

 protoxide of manganese ; and into these it may be resolved by 

 being boiled in dilute sulphuric acid. 



The colour of the deutoxide of manganese varies with the 

 source from which it is derived. That which is procured by 

 heat from the native peroxide or the hydrated deutoxide, has a 

 brown tint ; but when prepared from the nitrate of manganese 

 it is almost as black as the peroxide itself, and the native deut- 

 oxide is of the same colour. 



On heating a mixture of the deutoxide of manganese and con- 

 centrated sulphuric acid, oxygen gas is evolved with efferves- 

 cence, and the protosulphate is generated. In the cold the acid 

 acts upon it slowly, and acquires an amethyst-red colour ; but 

 this eflect does not take place so readily as with the red oxide. 

 The solution is attended with the disengagement of a little oxy- 

 gen, a circumstance from which it may be inferred that a por- 

 tion of deutoxide is resolved into oxygen and the red oxide, and 

 that the latter, on being dissolved, is the cause of the red colour. 

 ARFWEDSON represents the deutoxide as yielding a deep grass- 

 green coloured solution with sulphuric acid ; but I have never 

 been able to observe this phenomenon. 



Strong muriatic acid acts upon the deutoxide in the same 

 manner as on the red oxide of manganese, excepting that the 

 acid acquires the deep red tint more rapidly with the latter than 

 when the former is employed. It is hence probable that the red 

 colour is really communicated by the red oxide. 



