Theory of the Chemical Elements. %$>?> 



Lithium, Potassium, Rubidium, Caesium. — For these 

 elements the Hollowing formulas may be suggested : — 



Lithium, H 2 Nu 3 = 6-90 (CrOi), 



Potassium, 2{Nu 2 (PfH) 3 }H 2 Nu 2 Pf 3 = 39'08 (39-1), 



Rubidium, 4{Nu 4 (PfH) 3 }He 4 H 3 =85-44 (85*45), 



Caesium, 4{Ee 4 (PfH) 3 }{Nu 4 (PfH) 3 }He 3 = 132*81 (132-81). 



The case of lithium has been discussed already. The 

 formulae present a definite scheme of: development with 

 atomic weight increasing, and their groupings have obvious 

 relations with those of the inert gases. The relations among 

 the metals themselves are of the kind which would be ex- 

 pected on the view that the elements are the representatives 

 of definite positions of stability which have been reached in 

 an evolution of matter from its simplest forms. The pro- 

 perties of these stable systems may be expected to recur at 

 certain intervals, for example, alkaline properties and their 

 chemical associates recur with the groups just written. 

 Other groups of a similar kind might be written down with 

 perhaps similar properties, but capable possibly of only a 

 transitory existence, as in the case of radioactive products. 

 The discovery of radioactivity has already led, as Sir William 

 Ilamsay pointed out in his Presidential Address to the British 

 Association at Portsmouth, to the isolation of twenty-seven 

 new u elements," many of which have been shown to possess 

 definite chemical properties. The Periodic Table cannot 

 take account of all unstable as well as stable elements, except 

 on the view that the complete table should contain many 

 times the present number of elements, in which the present 

 set would be but isolated units, and such that the table 

 should find places for whole groups at present unknown, or 

 perhaps represented by a single member, as possibly, for 

 example, in the case of sodium or manganese. 



The real existence of a general scheme of this kind is an 

 immediate deduction from the growing belief that all matter 

 is to a certain extent radioactive. Campbell has detected 

 the effect even in potassium, which perhaps gives a series of 

 products for which the present table has no place. Radio- 

 activity can easily be overlooked if the velocity of the ex- 

 pelled particles is below a certain value. It is a process of 

 devolution of matter, and if the a particle were endowed 

 with considerable mass it could not be detected. A gas like 

 neon may be an u particle from certain kinds of matter, and 

 it is probable that all the inert, gases are waste products of 

 this nature, which have accumulated in the atmosphere. 



