Weight of Beryllium. 



69 



Let us consider the molecular volumes, i. e. the relative 

 volumes of the single chemical molecules and their relations 

 to the unit volume, i. e. the inverse values of molecular volumes 

 if we assume the highest volume as a unit. If we compare 

 these values with the inverse values of the molecular heats 

 obtained in the same way, the several groups exhibit very 

 closely corresponding numbers, e. g. in the third group: — 





Molecular 



Molecular 



Volume. 



Heat. 



Volume. 



Heat. 



B 



19 

 13 

 18 

 17 

 23 

 19 

 25 



8-3 

 94 

 104 

 9-8 

 11-6 

 111 

 12-2 



1-3 



1-9 

 1-4 

 1-5 

 1-1 

 1-3 

 10 



1-4 



1-3 

 1-2 

 1-2 

 11 

 11 

 1-0 



Al 



Sc 



Ga 



Y 



In 



La 





Although the last numbers are not absolutely identical in both 

 columns, yet there can be no doubt that these relations are not 

 due to mere chance. It is evident that the smallest molecular 

 heat corresponds to the smallest molecular volume. Perhaps 

 some relation may be found between these facts and Mende- 

 lejeff's hypothesis on the structure of molecules. 

 Hence it is clear that the relations between 



molecular volume 

 molecular heat 



are approximately = const. 



vol. 



heat 



5 A 



«, or the 



The following examples show that we have 



constant = 1*66 ; and it is strange that the variations are not 

 larger with such different experimental material. 



Cu 2 



BeO 



(Li 2 



MgO 



CaO 



ZnO 



HgO 



Be 2 3 



A1 2 3 



Sc 2 3 



Ga 2 3 



ln 2 3 



1-26 

 1-34 

 1-4) 

 1-54 

 1-80 

 1-41 

 1-73 

 2-29 

 1-37 

 1-69 

 1-74 

 1-73 



Y 2 3 



La 2 3 



Si0 2 



Zr0 2 



8n0 2 



Ce0 2 



Th0 2 



Mo0 3 



Er 2 3 

 Yb 2 3 



1-74 

 2-06 

 1-97 

 1-59 

 1-60 

 1-69 

 1-85 

 1-73 



2-09 

 1-69 



DioO s 1-78 &c. 



