Chemical Science. 151 



black, and without lustre, dissolving in muriatic acid, and 

 liberating pure sulphuretted hydrogen. It is composed of 



Manganese . • 100 



Sulphur . . , 56.32 

 M. Berthier then enters into an account of various double 

 sulphurets, which, though highly interesting, we have not room 

 to notice at present. — Journal des Mines, vii. 421. 



3. On Compounds of Nickel, by J. L. Lassaigne. — The object 

 of M. Lassaigne was to ascertain directly the representative 

 number of nickel, by experiments on its compounds. They 

 were made, we presume, with perfectly pure nickel, obtained by 

 M. Laugier's process ; for the principal reason for their being 

 undertaken, was the discovery by M. Laugier, that the nickel, 

 generally considered as pure, contained a large proportion of 

 cobalt. 



Protoxide of Nickel. — A given weight of pure nickel was 

 dissolved in pure nitric acid, evaporated to dryness, and de- 

 composed by heat. It was of a gray colour, soluble in acids, 

 precipitated by alkalis as a hydrate, «Src. Composition, 

 Nickel .... 100 

 Oxygen .... 20 



Deutoxide of Nickel. — Obtained by diffusing hydrate 

 of nickel in water, and passing a current of chlorine through 

 it ; one part is dissolved, and the other converted into peroxide 

 of nickel. It is of a brilliant black colour; heated, it loses 

 oxygen and becomes protoxide. Acids dissolve it, liberating 

 oxygen, except muriatic acid, which produces chlorine with it. 

 Its composition was ascertained by its loss of weight when 

 heated, and appeared to be. 



Nickel . . 100 > , , , i 100 



Oxygen . . 39.44 \ °' "^^^^^"^ ^^ ^^^^'^^ I 40 



Sulphuret of .Nickel. — Prepared directly from its elements. 

 It is of a yellow colour like iron pyrites, and very brittle. 

 Insoluble in sulphuric and muriatic acid, but decomposed by 

 nitro-muriatic acid. It was analyzed by calcination with nitre, 

 and the sulphuric acid determined by barytes. It was com- 

 posed of 



Nickel . . 100 ) , ,, ^ 100 



Sulphur . . 41.3 5 ^y^^^^^^y \ 40 



