THE PERIODIC LAW. 



VRNABLE'S TABLE. 1895. (SLIGHTLY MODIFIED.) 



163 



H 



He? 



Li 



Gl 



Na 



Cu 



B 



Mg 



Rb 



Cs 



/ 



Al 



Sr 



Ag 



Ba 



Au 



zA 



Cd 



La 



Hg 



ok 



In 



C 



Ce 



Tl 



Th 



Pb 



N 



O 



F 



Ne? 



Cb 



Ta 



Sb 



A 



Mo 



W 



Bi 



U 



Se 

 Te 



CI 



Ar? 



Mn 



Br 



Fe 



Ru 



Os 



Co 

 Rh 



Ir 



Ni 



Pd 



Pt 



* t Possible elements, now unknown. 



Eka-Manganese . 



Most tables present a difficulty in that they place sodium in the 

 group or sub-group with copper, silver and gold, while it would most 

 naturally fall in the group with lithium, potassium, rubidium and 

 cesium. So magnesium would be placed according to its properties, 

 not so closely with zinc and cadmium, as with glucinum, calcium, stron- 

 tium and barium. Fluorin belongs rather with chlorin, bromin and 

 iodin than with manganese, the metal with which it is associated in 

 most tables. So oxygen belongs with sulfur, selenium and tellurium, 

 rather than with chromium and molybdenum. This is remedied in 

 Yenable's table. The first element in any group the author calls 

 the group element or bridge element; for it often possesses properties 

 which ally it to the elements of the next groups. The second element 

 he calls the type element, and in this is, as it were, shadowed forth 

 the character of the succeeding elements of the same group. From this 

 point on, the group is divided into two series, one more and the other 

 less electro-positive or negative, as the case may be. The first three 

 groups are for the most part made up of electro-positive elements, while 

 those of the fifth, sixth and seventh groups are relatively electro- 

 negative. Now in the former the elements of the more positive series 

 resemble the type element of their group more strongly than those of 

 the less positive series. In the relatively negative fifth, sixth and 

 seventh groups, the reverse is the case. This grouping thus places 

 sodium with potassium and chlorin with bromin. In the fourth group, 



