Hackh — Modification of the Periodic Table. 489 



So, for example, the groups and subgroups of the ele- 

 ments are clearly separated, bringing thus the respective 

 elements closer together. From a study of the table we 

 may draw the rule that the similarity among the proper- 

 ties of the elements in the upper half of the table is move 

 pronounced in the vertical direction (analogy in groups), 



Vb 

 IVb 



nib 



lib 

 lb 



III 



IV 



V" 

 V 



VI 



4 



5A 



6A 



7A 



Group 





1A 



2A 



3A 



4 



62 



Pb 



83 

 Bi 



84 



Po 



85 





86 

 Nt 





87 



88 



Ea 



89 



Ac 



90 

 Th 



50 

 Sn 



51 

 Sb 



52 



Te 



53 

 I 





54 

 Xe 





55 

 Cs 



56 



Ba 



57 

 La 



58 

 Ce 



32 



Ge 



33 



As 



34 

 Se 



35 

 Br 





36 



Kr 





37 



Eb 



38 



Sr 



39 



Y 



40 

 Zr 



14 

 •Si 



15 

 P 



16 

 S 



17 

 CI 





18 



Ar 





19 

 K 



20 

 Ca 



21 



Sc 



22 



Ti 



6 

 C 



7 

 N 



8 

 



9 

 F 





10 

 Ne 



2 



He 





11 

 Na 



3 



Li 



12 



Mg 



4 

 Be 



13 

 Al 



5 

 B 



14 

 Si 



6 

 C 



1 



H 



22 



Ti 



23 



V 



24 



Cr 



25 



Mn 



26 

 Fe 



27 

 Co 



28 



Ni 



29 



Cu 



30 

 Zn 



31 

 Ga 



32 



Ge 



40 

 Zr 



.41 

 Cb 



42 



Mo 



43 



44 

 Eu 



45 

 Eh 



46 

 Pd 



47 

 Ag 



48 

 Cd 



49 

 In 



50 

 Sn 



58 

 Ce 



59 t 

 Pr 1 



50 61 

 Id 



62 ( 



Sm 



53 64 



Su Gd 



65 



Tb 



66 67 



Vy Ho 



68 

 Er 



69 70 



Tm' Tm 



71 



" To 



72 



Lu 



72 

 Lu 



73 



Ta 



74 

 W 



75 



76 

 0s 



77 

 Ir 



78 

 Pt 



79 



Au 



80 

 Hg 



81 



Tl 



82 

 Pb 



90 



Th 



91 



Bv 



92 

 D 







VI 

 Va 



IVa 



Ilia 



Ha 

 la 



III 

 IV 



5B 6B 



7B 



Group 8 



IB 



2B 



3B 



4E 



Table III. The periodic table, showing groups and periods. 



while the similarity among the elements in the loiver half 

 of the table is more pronounced in the horizontal direc- 

 tion {analogy in periods). Accordingly we may speak 

 of group relations and period relations, e. g., the group 

 relation of Au is in regard to Ag and Cu, while the 

 period relation of Au is in regard to Hg and Pt. Or in 

 other words, we may say, e. g., that the chromium group 

 includes Cr, Mo, W, U ; while the chromium period may 

 embrace Cr, Mn, Fe, Co. 



