102 



KANSAS ACADEMY OF SCIENCE. 



ments of the positions they occupy; but in the absence of positive knowledge, 

 they are allowed to remain in the series as placed by Mendel(5eff , 



Sodium Octave. 



The differences in atomic weight between Na and Mg, between Al and Si, and 

 between P and S, are minor steps; the differences between Mg and Al, between 

 Si and P, and between S and CI, are major steps. They recur regularly. 



Potassium Hecdecade. 



Valence. 



I 



II 



Ill 



IV 



Ill, V 



II, VI 



II, IV I 



(VII) \- 



II, IV / 



VIII \ 



II, I 



II 



Ill 



IV 



III, V 



II, VI 



I, VII 



Ni and Co appear to be doublets or twins. So, also, appear Mn and Fe. They 

 are complementary to each other. Ca and Se are each one side of its systematic 

 position. Their complementary elements are yet to be discovered. 



