wells: periodic system 



233 



with clockwise rotation. Each group is thus arranged radially, 

 the subgroups being shghtly displaced. 



The table appears to me to have all the advantages of the space 

 double helix, and is much simpler. It overcomes the artificial- 



ThEir..Ra.Ein 



Fig. 1. Spiral table illustrating the electron theory 



ity of the spiral of period sixteen,, which has two half turns 

 containing no corresponding elements. It brings the subgroups 

 and main groups together, as in Mendeleef's table. 



The spiral table is particularly adapted to illustrating the 

 electron theory. Thus each turn represents a ring of eight 

 valence electrons. The vertical axis represents in a general way 

 the transition from positive to negative valence. To the right 



