354 



allotropic variety. BotTi modifications lead to nearly the same 

 specific results. 



The indium employed showed itself to be entirely free from 

 tin, cadmium and iron. Oxidised by nitric acid and evaporated 

 with sulphuric acid, it left upon solution in alcohol, no trace of 

 plumbic sulphate. 1-0592 grams of the metal dissolved without 

 loss in nitric acid, gave after evaporation and ignition 1-2825 

 grams indie oxide. If the latter, according to the previous views, 

 be considered as consisting of equal atoms, there results from 

 this determination the value for the atom of indium, In=37-92, 

 which number agrees very closely with the one determined by 

 Winkler, In-37-81. This atomic weight, multiphed into the 

 obtained specific heat S^, gives, however, for the atomic heat of 

 indium the value, S^ In =2 13, which does not agree with the 



The previously accepted hypothesis, that indie oxide is con- 

 stituted according to the formula InO, appears therefore no 

 longer tenable. If the atomic weight be accepted as once and 

 a half so great, In=56-7, then will the atomic heat be, S>= 

 3-23, nearly equal therefore to that of the other elements. The 

 atomic weight 56-7 removes the anomaly, that indie oxide which 

 was previously considered monacid, is, according to its entire 

 deportment, analogous to that class of trin-acid bases, which 

 forms no alums. For the previously accepted formulae, given 

 in column I of the following table 8, must therefore be sub- 

 stituted the ones in column II. 



Black indions oxide, InO ? InO ? 



Yellow indie oxide, InO IngOg 



Gr«^en indious-indic oxide, 5lnO, IngO 2lnO, IngOj 



Gray indous-indic oxide, 4lnO, In^O 3lnO, 210303 



Hydrous indie oxide, InO,' HO In2O3,3H0 



In.lic sulphate, InO, SO,, 3H0 In^O,, 3SO3, 9H0 



Indie chloride, In€l In^eig 



"^"chlorideT ''''''' [ 2^4^1. 3ln€l, 2H0 2?fH,€l, lu,eU,2W 



The ammonium-indic-chloride, prepared by E. G. Meyer, and 

 cited in this scheme, possesses, according to the new formula, an 

 analogous composition with ammonium rhodic chloride, wbicn 

 likewise contains 2 atoms of water. Whether or no the alterea 

 atomic weight finds comfirmation in an isomorphism m these 

 salts I have been unable to investigate ; I shall, however, return 

 to this subject in a research, to be published later, on rubidium- 



During this winter, for such experiments very unftworaD ^ 

 I have been unable to make a trial of the instrument as to j 

 L of the latent heats of melting. 



