Chemical and Physical Properties of Elements. 31 



members bv letters and numbers in some sucb way as the fol- 

 io win o-: — 



3 



u 



5 



6 



7 



fl 

 2 



3 



b{ 4 



2 



fl 

 2 

 3 



fl 



a 



5 



La<(4 II.a<{4 III. ^ 



o 



I? 



D 



I 6 



fl 

 2 

 3 



5 

 6 



17 



IV 



fl 

 I 2 



! 3 

 r«^4 



5 

 6 



7 



2 



3 



5 

 6 



7 



"M 



5 



I 6 

 17 

 i 



fl 

 2 

 3 

 c^ 4 

 5 

 6 

 17 



fl 

 g 



I 3 



17 

 (i indicates the intermediate groups.) 



According to this system, the main family of the alkaline 

 gronp is I. a 1, II. a 1. III. a 1, IT. a 1, T. a 1 ; and with this 

 are connected the various members of the group as follows : — 



.III- 



ol -lV.«l-V,«l 



H— I. a 1— II. a l' 



nr.*i-i* 



£i 



V. A 1 

 Y. c 1 



V. ,/ 1 



By this method each element, whether known or unknown, 





