of the Metallic Oxides. 

 Table (continued). 



87 





Mole- 

 cular 

 weight. 



Physical 

 state. 



Fusibility. 



Volatility. 



rPbCl 2 



IpbO 



278 



223 



287 



232 



111 



56 



158-5 

 103-5 

 208 



153 



95 



40 

 136 



81 

 183 

 128 

 191 

 136 



12975 



74-75 

 80-25 

 2525 



376 



266 



Solid. 



Solid. 



Solid. 

 Solid. 

 Solid. 

 Solid. 

 Solid. 

 Solid. 

 Solid. 



Solid. 



Solid. 

 Solid. 

 Solid. 

 Solid. 

 Solid. 

 Solid. 

 Solid. 

 Solid. 



Solid. 



Solid. 

 Solid. 

 Solid. 

 Solid. 

 Solid. 



Fuses 498°. 



Fuses about a red-heat. 



Fuses 451°. 



Infusible. 



Fuses 719°. 



Infusible. 



Fuses 825°. 



Infusible. 



Fuses above 860°. 



f Fusible in oxyhy- "1 



\ drogen flame. j 



708°. 



Infusible. 



Fuses 262°. 



Infusible. 



Fuses 541°. 



Infusible. 



Boils 861°-954°. 

 f Volatile at white- 

 \ heat. 



j'Ag 2 01 2 



Ug 2 



fCaCl 2 



[CaO 



Decomposes. 

 Fixed. 



J'SrOL 



\SrOf 



Fixed. 



rBaCl 2 



iBaO 



Fixed. 



Volatile. 



Fixed. 



Boils 676°-683°. 



Fixed. 



Boils 861°-954°. 



Fixed. 



Volatile. 



Fixed. 



jM g Cl 2 



IMgO 



/ZnCl, 



\ ZnO." 



1 CdCl 



1 OdO 



pci 2 



1 uo 



Infusible. 

 j Sublimes without 1 

 |_ fusion. J 



Infusible. 

 Fuses 585°-617°. 



Infusible. 



rNiCl 2 



INiO 



Fixed. 



Volatile below 520°. 



Fixed. 



Sublimes. 



Fixed. 



fBeCl 2 



\BeO 



{ThCl 4 



\Th0 2 



Infusible. 



As already stated, this difference in properties is observed 

 especially in the oxides and chlorides of positive elements, and 

 in general in elements having a metallic brightness. It may 

 be noted by the way that it appears to be the greater the higher 

 the atomicity of the metal. 



Whatever may be its meaning, this physical difference is, 

 by its generality, one of the most remarkable facts in statical 

 chemistry, strange and, at first sight, quite exceptional. 



The properties of compound bodies do not appear by chance; 

 they are only the final result of the properties of the consti- 

 tuent elements — a result more or less modified in consequence 

 of the physical phenomena of combination. Chemical com- 

 pounds are therefore really mixtures of a special kind. It 

 cannot be denied that the properties of compounds are closely 

 related to those of their principal constituents. The differences 

 between certain elements occur again with greater or less 

 fidelity in their corresponding and comparable compounds. 

 That being so, the behaviour of the metallic oxides is especially 



