PROTOCOMPOUNDS OF TIN. 



absorbs half an equivalent of that gas, according to Persoz, 

 forming 2Sn C1 + NH 3 , or probably a double salt like the pre- 

 ceding salt of ammonium, that is, Sn Cl + (NH 3 Sn), Cl. 



Protiodide of tin, Sn I, is formed by heating a mixture of 

 granulated tin and iodine. It was found by Bouliay, jun., 

 to form double salts with other iodides, particularly with the 

 iodides of the alkaline and earthy metals, in which two atoms 

 of the stannous iodide are combined with one of the other 

 iodide. 



Carbonate of tin. Carbonic acid does not combine with 

 either of the oxides of tin. 



Protosulphate of tin, Sn O, SO 3 . Tin dissolves in sulphuric 

 acid concentrated or a little diluted, and affords a saline mass, 

 which forms a brown solution in water and deposits small cry- 

 stalline needles on cooling. 



Protomirate of tin, Sn O, NO 5 , is obtained by dissolving 

 protoxide of tin in nitric acid ; the solution cannot be concen- 

 trated and is easily altered. 



Tartrate of potash and tin, KO. Sn O + (C 8 H 4 O 10 ). Bitar- 

 trate of potash dissolves protoxide of tin, and forms a very so- 

 luble salt of potash and tin, which, like most of the tartrates, 

 is neither precipitated by caustic alkalies, nor by alkaline car- 

 bonates. An addition of bitartrate of potash is occasionally 

 made to the solution of tin used in dyeing. 



Deutoxide of tin, Sn 2 O 3 , 1770.6 or 141.88. Was obtained 

 by M. Fuchs, by diffusing recently precipitated peroxide of iron 

 in a solution of protochloride of tin, containing no excess of 

 acid, and afterwards boiling the mixture. A double decompo- 

 sition occurs, in which the deutoxide of tin precipitates, and 

 protochloride of iron is retained in solution : 



2Sn Cl and Fe 2 O 3 = Sn 2 O 3 and 2Fe Cl. 



The deutoxide thus obtained is a slimy grey matter, and usually 

 yellow from adhering oxide of iron. Ammonia dissolves it 

 easily, and without a residue, which distinguishes this oxide 

 from the protoxide of tin, the latter being insoluble, or almost 

 so, in that menstruum. The deutoxide of tin is dissolved by 

 concentrated hydrochloric acid ; the taste of the solution is not 

 metallic. It is distinguished from a salt of the peroxide of tin, 

 by producing the purple precipitate with chloride of gold. A 



