Manchester Memoirs, Vol. li. (1907), No. 6. 



Add f- 0-8980 

 + 07902 

 -0-9686 



1 7 '94 



1-0764 



1-930 



Calculated atomic weight of K = 39-596 



All the other atomic weights have been calculated in 

 the same way. 



In the diagram, which reproduces the table, the inter- 

 sections of the sixteen equi-distant vertical group lines, 

 with the slanting group lines which are supposed to be 

 drawn on a cylindrical surface, were marked with the 

 atomic weights found by the formula, and the positions of 

 the elements were then fixed by interpolation. Subse- 

 quently the elements of each of the groups were connected 

 by lines. The Iron group is represented by three lines. 



Table I. 

 GROUPS OF CHEMICAL ELEMENTS. 



Elements. 



Atomic 



Weights. 



Group 

 Position. 



Calculated 

 At. Wt. 



Difference. 



Group O or XVI. 



Mean position 15-93. 



Helium 

 Argon . 

 Krypton 

 Xenon 



He 



4-00 



i6 - oo 



Ar 



399° 



17-16 



Kr 



8r8o 



1577 



X 



128*00 



16-04 



3-84 

 36-81 



82-25 



127*71 



+ 0-16 

 + 3-09 



-°"45 

 + 0*29 



* The grouping in this table is based on that of Mendeleeff, but with 

 the atomic weights brought up to date. Recently discovered elements are 

 also included. 



