284 Notices of the Labours of Continental Chemists. 



and at the same time a heavy white powder is formed ; this 



is bin-antimoniate of potassa, K Sb + 6 H. If the solution be 



evaporated to a certain point, and then allowed to cool, a 

 colourless salt separates in long acicular crystals; they are 

 not deliquescent, but soon become covered with a brown 

 substance. They are soluble in boiling water, but decomposed 

 by cold water, by which part is dissolved, and antimoniate 

 of potash remains behind. This is a compound of the stibio- 

 persulphuret with antimoniate of potash. Its formula is 

 (3 K S + Sb 2 S 5 + 9 H 2 O) + (K O + Sb 2 O 5 + H 2 O), or 



(K 3 Sb + 9H) + (K Sb + H). With soda no such salt 

 can be obtained. 



Stibio- sulphur et of Sodium. — Schlippe's salt crystallizes in 

 tetrahedrons ; subordinate are the faces of the second tetra- 

 hedron, dodecahedron, and tetratrishexahedron (a: -acca). 



The solution of this salt, by exposure to the air, deposits a 

 reddish-brown powder: in the solution are contained car- 

 bonate and hyposulphite of soda. As to the formula of this 

 salt there is some degree of uncertainty. Different formulae 



have been given. Duflos's is Na 2 Sb + 8 H; Liebig's, Na Sb 



-f 12 H; Schlippe's, Na 3 Sb -f- 20 H. Rammelsberg found 



Na 3 Sb + 18 H. 



The barium salt can be obtained crystallized j its formula is 



Ba 3 Sb + 6H. 



The ammonium, strontium, calcium and magnesium salts 

 do not crystallize; they all, however, contain three atoms of 

 basic sulphuret. 



To obtain the pure metallic stibio-sulphurets, the solutions 

 of the metallic salts must be added gradually to an excess of 

 the alkaline stibio-sulphuret. 



The silver, lead and copper salts, obtained in this manner, 



have the formulae Ag 3 Sb, Pb 3 Sb, Cu 3 Sb. When the silver 

 salt is heated sulphur is given off, and a substance remains 

 having the formula Ag 3 Sb, the same as red silver; by heat- 

 ing the lead compound, Pb 3 Sb is obtained ; this is the com- 

 position of Boulangerite. With corrosive sublimate the salt 



Hg 3 Sb may also be obtained. With sulphate of zinc an 



