776 Prof. H. E. Armstrong on Low-Temperature Research 



Russian's generalizations, having always been struck by the resem- 

 blance brought out by the "periodic" arrangement of elements 

 with those presented by carbon compounds when classified according 

 to their homologous and isologous relationships : — 



"Although no direct evidence acceptable to chemists has been 

 adduced which in any way justifies the belief that the elements are 

 decomposable, it is impossible to resist the conclusion that they are 

 genetically related — so closely in many respects do they resemble 

 a series of related compounds, especially when regarded from the 

 point of view of the organic chemist. The generalization known 

 as the periodic law is in itself a justification of this view, the 

 manner in which inter-relationship becomes manifest when they are 

 classified in accordance with its canons being probably the strongest 

 of all the arguments which can be cited as tending to show that 

 the elements are compounds — but compounds very different from 

 those with which we are accustomed to deal" (R. Soc. Proc, vol. 70, 

 86 : vol. 87, 204.) 



The subject was further developed in the Graham Memorial 

 Lecture in 1912 (Glasgow Philosophical Society, Proceedings; cp. 

 Science Progress, vi. 584). 



Sir James Dewar has not yet placed on record the results he has 

 obtained with organic compounds but I know these are of a remark- 

 able and most suggestive character. The study of such compounds 

 is of altogether special importance, now that the simplicity of the 

 primary materials from which they are formed is suspect. 



The most remarkable feature of all the cases of spontaneous de- 

 composition of radio-active materials hitherto studied is the produc- 

 tion cf helium gas as one of the products. In so far, therefore, as 

 known primary materials have been shown to be of a complex 

 nature, they are proved to be compounds of helium. They may, in 

 fact, be contrasted with the hydrocarbons. As helium is an entirely 

 inert gas, it is difficult to believe that it is present " as such " ; I am 

 still inclined to think that the molecule will ultimately be found to be 

 complex, just as hydrogen, as we know it, is a complex molecule (Ho), 

 the constituent radicle of the molecule (H) being the combining unit 

 present in hydrogen compounds. Indeed, while accepting most of 

 the conclusions based upon the study of radio-active change, chemists 

 cannot well adopt forthwith all the views put forward by the distin- 

 guished school which has added so wonderful a new chapter to our 

 knowledge and has so revolutionized our views of nature. 



Sir James Dewar's latest determinations of the rate at which helium 

 is given off" from radium have been made known during the septennate. 

 They show it to be slightly under one-half of a cubic milHmetre ppr 

 day. So far as is known, the decomposition of radium and similar 

 materials is an entirely spontaneous process dictated by some inner 

 necessity — one which cannot be either assisted or controlled by any 



