150 Miscellaneous Intelligence. 



boiled in water, gave a solution of hydro-sulphuret of magnesia, 

 and pure magnesia remained ; 1.5, acted on by water, gave a 

 solution contain 0.18 magnesia; 1 heated with nitre, &c., gave 

 0.85 sulphate of baryta, equivalent to 0.12 sulphur. The sul- 

 phuret of magnesia is composed therefore of 



/Magnesium . 0.072] f0.094 



(Sulphur . . 0.120lor by theory 1 0.120 



Magnesia . . 0.780j lO.786 



972 1.000 



To accord with the theory, the loss should have been 0.608, 

 instead of 0.605. 



Sulphuret of Copper. — 10 of dry sulphate gave 4.76 of sul- 

 phuret, mixed with a few grains of metallic copper. M. Ber- 

 thier ascertained that there was no action between this sulphuret 

 and metallic copper ; therefore, probably no sulphuret con- 

 taining less sulphur exists. 



Sulphuret of Zinc. — 30 parts of sulphate gave, in one experi- 

 ment, 4.5 parts; in another, 13.2. The sulphuret produced 

 was of a flaxen colour, and in crystalline grains, composing a 

 friable mass. When analyzed, it proved to be of the same com- 

 position as blende, i.e., 



Zinc 100 



Sulphur .... 50 



In the experiments on zinc an excessive loss occurred, which, 

 after some trials, M. Berthier traced to the action of the char- 

 coal on the sulphuret. He found that a piece of native blende 

 thus heated, lost in two hours ^^^ of its weight, and if powdered 

 and mixed with charcoal, the whole would have been dissipated 

 in a short time. This action is attributed to the affinity of the 

 carbon for the sulphur ; and it was ascertained, by heating a 

 mixture of charcoal and sulphuret of antimony, that an analo- 

 gous action took place, for the gaseous products being made to 

 passthrough a condenser, a 'considerable quantity of sulphuret of 

 carbon was procured. Sulphuret of iron, of copper, and many 

 other sulphurets, diminish in weight, when heated with char- 

 coal, from the same cause. 



Sulphate of Lead, with charcoal, gives a sub-sulphuret of 

 lead, which, by further heat, is partly volatilized, and partly 

 decomposed. 



Sulphuret of Manganese is easily obtained. It is pulverulent, 



