528 MANGANESE. 



it is found in volcanic sand at Expailly in France, in Ceylon, 

 and some other localities. The earth is obtained from this 

 mineral, which is more difficult of decomposition than most 

 others, by processes for which I must refer to Berzelius. 

 (Traite, t. 1, p. 32!).) 



Zirconia is a white earth, like alumina in appearance, of 

 density 4.3. Its hydrate, after being boiled, is soluble with 

 difficulty in acids. When heated it parts with its water, after- 

 wards glows strongly, from a discharge of heat, becomes denser 

 and less susceptible of being acted on by reagents. It forms a 

 carbonate. When once separated from its combinations, it is 

 insoluble in carbonate of potash or soda, but dissolves in them 

 in the nascent state. The salts of zirconia have a purely as- 

 tringent taste. It agrees with thorina in being precipitated, 

 when any of its neutral salts are boiled with a solution of sul- 

 phate of potash. 



ORDER IV. 



METALS PROPER HAVING PROTOXIDES ISOMORPHOUS WITH 

 MAGNESIA, WITH BISMUTH. 



SECTION I. 



MANGANESE. 

 Eg. 345.9 or 27.72 5 Mn. 



This element is found in the ashes of plants, the bones of 

 animals, and in many minerals, of which that employed in the 

 preparation of oxygen is one of the richest. The black oxide 

 of manganese was long known as magnesia niyra, from a fancied 

 relation to magnesia alba, but was first thoroughly studied by 

 Scheele in 1774, and by Gahn immediately afterwards, who 

 obtained from it the metal now named manganese. 



From its strong affinity for oxygen and the very high tempe- 

 rature which it requires for fusion, manganese is one of the 

 metals proper, which is reduced and fused into a button with 



