68 



Dr. B. Brainier on the Atomic 





I. 



n. 



ILL 



IV. 



V. VI. 



2. 

 3. 

 4. 

 5. 

 6. 



n 



s. 



9. 

 10. 

 11. 



12. 



Li (5) 



Be 6-2 



9-7 Mg 

 CalOO 

 101 Zn 



li : 2Hg 



B 8-3 



94 Al 

 Sc 104 



9-8 Ga 

 Y 11-6 



11-1 Zn 

 La 122 



11-5 Si 

 Ti 140 



Zr 133 



140 Sn 

 Cel5-0 



Thl45 





Mo 191 



W 18-5 



These show that the so-called Neumann's law forms but an 

 approximate expression for the relations of specific heat to 

 composition, and is therefore not of such cardinal importance 

 for the solution of the present question as Messrs. Nilson and 

 Pettersson assume. On the contrary, those gentlemen have 

 themselves furnished us with the experimental materials for 

 establishing the following proposition : — " The oxides of one 

 ■natural group have nearly the same molecular heats; but these 

 rise with increasing atomic weight." Further investigations 

 must show if this is also the case in the horizontal series. 



The molecular heat of the supposed trivalent beryllium is 

 here seen to approach nearly to that of alumina ; for 



but also 



|BeO = iBe 2 O 3 =9-30, 1A1 2 3 =9«39 ; 

 §B a 8 = ll\L, Si0 2 = ll-5. 



In the same way the molecular heat of lithia, -|Li 2 O, may be 

 calculated to be about 5. 



The smallest molecular heat will correspond to the smallest 

 volume of Li 2 0, and the next larger values will be shown by 

 beryllia. The three above-mentioned relations again find their 

 expression in the equation 



Li: Mg = Be : A1 = B : Si. 

 In the Russian edition of his ' Principles of Chemistry' (vol. ii. 

 p. 710 et seq.) MendelejefP has speculated on the possible 

 reason of the fact that several compounds possess a smaller 

 molecular heat than others. He arrives at the conclusion that 

 those solid bodies whose molecule may be supposed to be a 

 more complicated one, have a smaller specific heat than those 

 which possess a less complicated structure. On this the fol- 

 lowing remarks may be made. 



* See also Journal of the Russian Chemical Society, 1873. 



