84 Dr. Turner's Chemical Examination 



On the Deutoxide. — This oxide is prepared by exposing the 

 nitrate or peroxide of manganese for a considerable time to a 

 rather low red heat. I have found great difficulty in procu- 

 ring it artificially in a pure state. After exposing the peroxide 

 for an hour or longer to a moderate red heat, the residue fre- 

 quently contains too much oxygen for constituting the deut- 

 oxide ; and on augmenting the temperature slightly, the loss 

 in oxygen is very apt to become excessive. The result is so 

 much influenced by slight differences of temperature, that I 

 do not feel confident in inferring the existence of the deutoxide 

 from such researches. That there is such a compound, how- 

 ever, is demonstrated by its occurring in two different states 

 in the mineral kingdom. My experiments as to its composi- 

 tion, as will afterwards appear, agree with the statement of 

 Berzelius, Arfwedson, and Thomson. It is intermediate be- 

 tween the protoxide and peroxide, consisting 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 equiva- 

 lent 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 manga- 

 nese it is almost as black as the peroxide itself, and the native 

 deutoxide is of the same colour. 



On heating a mixture of the deutoxide of manganese and 

 concentrated sulphuric acid, oxygen gas is evolved with ef- 

 fervescence, and the protosulphate is generated. In the cold 

 the acid acts upon it slowly, and acquires an amethyst-red co- 

 lour ; but this effect does not take place so readily as with the 

 red oxide. The solution is attended with the disengagement 

 of a little oxygen, a circumstance from which it may be in- 

 ferred that a portion 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 sul- 

 phuric acid; but I have never been able to observe this phe- 

 nomenon. 



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 



