70 



Dr. 13. Brauncr on the Atomic 



(5) The same alteration of atomic heat is observed in the case 

 of the OXygen contained in the oxides. Nilson has already 

 pointed out that the oxygen combined with metals, having 

 small atomic weight, also exhibits a small atomic heat. If we 

 arrange the values so obtained, as far as the insufficient mate- 

 rial allows, we get the following relations: — 





I. 



II. 



III. 



IV. 



V. 



VI. 



3. 



4. 

 5. 



6. 



7. 



8. 



9. 

 10. 

 11. 

 12. 



(1-8) Li 

 Oui-6 



2-4 Be 



Mg 3-8 

 3-4 Ca 



Zn 39 



"Hg4-8 



26 B 



A126 

 2-7 Sc 



Ga 2-9 

 3-5 Y 



In 31 

 4-0 La 



Si 2-8 

 3-8 Ti 



3-6 Zr 



Sn3-8 

 4-4 Ce 



4-0 Th 





4 1 Mo 

 41 W 



Thus we see that the atomic heat of oxygen increases with 

 the atomic v/eight, exhibiting a minimum in the upper corner 

 on the left. Therefore we can calculate that value to be for 

 lithia about 1*8. 



Hence the numbers obtained by Nilson for the molecular 

 heat of beryllia, and the atomic heat of the oxygen contained in 

 it, serve to prove the dyad nature of beryllium and its position 

 as II. — 2 more satisfactorily than the opposite conclusion on 

 the triad nature of the metal. 



(6) But all the chemical reactions of beryllium compounds, 

 some of them being different from those of the other dyad 

 metals*, may be explained by the three equations following, 

 from the periodic law: — 



(a) Li:Be=Be:B, 



(b) Li:Na=Be: Mg = B : Al, 



(c) Li:Mg = Be: A1 = B : Si. 



Beryllium is distinguished from the other metals of the 

 second group in the same manner as lithium is from the alka- 

 line metals, and as boron is from the triad elements. I will 

 not enter further into this question, as it has been thoroughly 

 treated by MendelejefF in his papers f, and especially in his 

 Russian ' Principles of Chemistry ' (vol. ii. p. 826). If we 



* See Nilson and Pettersson's paper, Wied. Ann. iv. p. 554. 

 t Ann. Chem. Pharm. Suppl. p. 8 - K Chem. News, xl. p. 303. 



