5ot MANGANESE. 



colours glass of a red or violet colour. The common violet or 

 purple stained glass, contains manganic oxide ; also the amethyst. 



Manganic oxide is a base isomorphous with alumina and the 

 peroxide of iron. It dissolves in cold hydrochloric acid, with- 

 out decomposition, and in sulphuric acid, with a slight diges- 

 tion. The manganic sulphate was found by Mitscherlich to 

 form an alum, with sulphate of potash. Its solutions have a 

 deep brown colour. At a higher temperature acids reduce the 

 deutoxide of manganese to the state of protoxide, with evolution 

 of oxygen gas. 



Sesquichloride of manganese (Mn 2 C1 3 ) is formed when 

 the deutoxide is dissolved in hydrochloric acid at a low tempe- 

 rature. The solution is yellowish brown or black, according to 

 its degree of concentration, and is decomposed by a slight ele- 

 vation of temperature, with evolution of chlorine. A corres- 

 ponding sesquifluoride may be crystallized. 



Sesquicyanide of manganese. A compound of this cyanide is 

 formed, when the protacetate of manganese is mixed with 

 hydrocyanic acid in excess, then neutralised with potash and 

 evaporated ; by the absorption of oxygen, the manganous cya- 

 nide is changed into hydrated manganic oxide and manganic 

 cyanide, which last combines with cyanide of potassium, and 

 appears, on the cooling of a concentrated solution, in red 

 crystals, which dissolve easily in water, (Mitscherlich). This 

 salt is analogous to red prussiate of potash, containing manga- 

 nese instead of iron, and may, therefore, be represented as 

 containing manganicyanogen a manganicyanide of potassium, 

 K 3 -f(M 2 Cy 6 ). As a double cyanide, its formula would be, 

 3KCy + Mn 2 Cy 3 . 



Red oxide of manganese, Mn O, Mn 2 , O 3 , named by 

 Berzelius manganoso-manganic oxide, is produced at all times 

 when any oxide of manganese is heated strongly in air. It is 

 a double oxide, being a compound of single equivalents of 

 protoxide and deutoxide of manganese. It forms the mineral 

 hausmanite, which differs from manganite in having rnanganous 

 oxide in the place of water. Its density is 4.722. Berthier 

 finds that strong nitric acid dissolves out the protoxide of man- 

 ganese from the red oxide, and leaves a remarkable hydrate of 

 the peroxide, of which the formula is 4MnO 2 + HO. 



Peroxide of manganese, Black oxide of manganese ; M-n O 2 ; 

 545.9 or 43.72. This is the familiar ore of manganese em- 



