$$2 



Dr. J. W. Nicholson on a Structural 



is very nearly the value for five helium atoms. The 

 ordinary value for radium gives only 19*3. But this point 

 must not be dwelt upon, as it seems probable that all the 

 particles are not helium, and there may be more than five. 



The results of this examinntion of the inert gases may be 

 collected into the following table, as a representation of the 

 first column of the Periodic Table. The practical value of 

 the atomic weight, when one is generally accepted, is placed 

 in brackets. 



Group T. 



Helium, He = Nu+Pf, 399 (3-99) 







Neon, 2(PfH) 3 , 20-21 (20-2) 



1- ' ■■■■ - 



Argon ? 5He 2 , 39-88 (3988) 







X 1 = 2{He 2 (PfH) 3 .Nu 2 (PfH) n }, 62-88 



Krypton, o{Nu 4 (PfH) 3 }, 83-08 (82-9) 







X 3 =2{He 4 (PfH) 3 .2Nu 2 (PfH) :{ }, 105*0 



Xenon, 5{He 4 (PfH; 3 }, 130-28 (130-2) 







Ac Em =2{2He 2 (PfH) 3 . 3Nu 2 (PfH) 3 ), 152-49 



X 2 =2{2Nu 4 (PfH) 3 .3He 2 (PfH) 3 }, 175-0 







X4 = 2{He 4 ('PfH) 3 . 4He 2 (PfH) 3 }, 196-76 



Niton, 2{2Nu 4 (PfH) 3 . 3He 4 (PfH)J, 2 22-8 





Other Groups of Elements. 



After this sketch, necessarily somewhat brief, of the group 

 of inert gases, we may proceed to consider other groups of 

 elements with chemical similarity. Only those of accepted 

 atomic weights are considered, and in particular, all the 

 elements of the rare earths are ignored, since they are 

 uncertain both in atomic weights and positions in the table. 

 It must be stated that in many cases the suggested groupings 

 are entirely provisional, and put forward partly to indicate 

 the possibility of the process. Many considerations, atomic 

 volume for example, would be necessary before anything of 

 a final character could be attempted. But on the whole the 

 system cannot be wholly fortuitous, and the results are 

 suggestive in many w r ays. 



