MANGANESE. 239 



is a compound of fluoride of aluminium with fluoride of 

 potassium. The latter constituent interferes in no wise 

 with the process. The method of preparing the chlo- 

 ride, as a material for the production of the metal, is 

 given in the section on Chlorides. 



592. ACTION OF ACIDS. Muriatic acid 



What is the . 



action of acids is its proper solvent, and forms with it a 

 colorless solution. Nitric acid whitens it, 

 if previously dipped into strong potash or soda. Dilute 

 sulphuric acid is without action. Aluminium may be 

 poured from one vessel to another in a fused condition 

 without oxidation. Like silver it may be deposited by 

 the galvanic process. 



593. It is highly sonorous, and therefore 

 other proper- adapted to manufacture of bells. This 



metal is now prepared in France at less 

 than three dollars per pound. The French government 

 propose to use it for helmets and cuirasses, for which 

 it is especially fitted by its lightness and tenacity. 



594. MANGANESE. Manganese is a 

 description, grey brittle metal, produced from its oxide 

 production, b heatnig w j t h charcoal. It is found in 



occurrence, 



solvents and nature as black oxide of manganese and as 

 a constituent of many other minerals. It 

 enters also in small proportions into the composition of 

 soils. Diluted sulphuric or muriatic acid are its proper 

 solvents, forming with it pale rose-colored solutions. 

 The black oxide serves as a source of oxygen, and is 

 also employed in the preparation of chlorine gas. It is 

 also used in the production of artificial amethysts, and 

 also to impart to glass the same violet tint. 



