1818.] Scientific Intelligence. 3S3 



ingredient, it is very possible that the Tyrol spodumene may 

 merely contain potash. 



XL Tantalite. 



This mineral, hitherto confined to Sweden, has been lately 

 found at Bodenmais, in Germany. Its specific gravity is 6-464. 

 Leonhard and Vogel extracted from it by mechanical division a 

 four-sided prism terminated by oblique faces, making angles of 

 94° and 86° with the sides of the prism. Vogel attempted to 

 analyze it by the method followed by Berzelius, but could not 

 succeed. He found its constituents as follows : 



Oxide of tantalum 15 



Protoxide of iron 17 



Protoxide of manganese 5 



Oxide of tin 1 



98 

 (Schweigger's Jour. xxi. 60.) 



XII. Action of Sulphur on the Muriates. 



Vogel has made a great number of experiments to ascertain 

 what takes place when a mixture of a muriate and sulphur is 

 exposed to heat. From these experiments he has drawn the 

 following conclusions. 



1. A great proportion of the metallic muriates are decomposed 

 by sulphur. 



2. The experiment does not succeed nearly so" easily with the 

 earthy and alkaline muriates as with the metalline muriates. 



3. JThe following muriates were decomposed by means of 

 sulphur : 



Protomuriate of tin, 

 Muriate of copper, 

 Muriate of manganese, 

 Muriate of lead, 

 Muriate of antimony, 

 Protomuriate of mercury, 

 Permuriate of mercury. 



4. During the decomposition of these muriates, sulphurous 

 acid gas, and in some cases sulphuretted hydrogen, was evolved, 

 and metallic sulphurets formed. 



5. Muriate of iron and muriate of zinc, when treated in this 

 way, would form no metallic sulphuret. 



6. Muriates of potash, soda, and barytes, when heated to 

 redness with sulphur, were very slightly decomposed. — (Schweig- 

 ger's Journal, xxi. 62.) 



XIII. Separation of Magnesia from Lime. 



In analytical chemistry it is a problem of considerable import- 

 ance to separate magnesia from lime when they happen to exist 



5 



