u of the Oxides of Manganese. 159 



drachms of strong acid to five ounces of water), a colourless so- 

 lution of the protosulphate is obtained ; while a portion of per- 

 oxide is left, the quantity of 'Which corresponds to the atomic 

 view just given; that is, 116 parts of the red oxide yield 44 parts 

 of the peroxide of manganese. 



When the red oxide is mixed with strong muriatic acid, a 

 portion of it is almost instantly dissolved, and communicates a 

 deep red colour to the liquid. But the solution is not perma- 

 nent. The odour of chlorine is perceptible from the beginning, 

 even at a temperature of zero of Fahrenheit ; the disengage- 

 ment of that gas continues slowly, though without distinct effer- 

 vescence, until in a few days the solution, if separated from un- 

 dissolved oxide, becomes quite colourless. The red oxide dis- 

 solves in hot muriatic acid with effervescence, owing to the evo- 

 lution of chlorine. 



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 procuring it artificially in a pure 

 state. After exposing the peroxide for an hour or longer to a 

 moderate red heat, the residue frequently contains too much 

 oxygen for constituting the deutoxide ; and on augmenting the 

 temperature slightly, the loss in oxygen is very apt to become 

 excessive. The result is so much influenced by slight differ- 

 ences of temperature, that I do not feel confident in infer- 

 ring the existence of the deutoxide from such researches. That 

 there is such a compound, however, is demonstrated by its occur- 

 ring in two different states in the mineral kingdom. My expe- 

 riments as to its composition, as will afterwards appear, agree 

 with the statement of BERZELIUS, ARFWEDSON, and THOMSON. 



