598 SCIENCE PROGRESS 



It is commonly assumed that helium and the allied gases are 

 inert chemically: the fact that they "give brilliant spectra under 

 the influence of the electrical discharge appears to me to be 

 direct disproof of the correctness of this view. In making this 

 statement I am assuming that electrical discharge in gases 

 takes place in virtue of the formation of complex systems and is 

 an electrolytic process. 



I see no particular difficulty in postulating the existence of 

 even a complex series of helium compounds; that such com- 

 pounds would exhibit remarkable properties is to be expected. 



One remark in passing— the " emanation " which is the first 

 product of the decomposition of radium has been classed as an 

 element of the argon group. But as it is eminently unstable, 

 this seems to be an illogical conclusion, as superlative stability 

 is the one property distinctive of the argonides. It is a 

 striking fact that this " emanation," itself derived from a metal, 

 is gaseous and non-metallic, especially as it is supposed that the 

 ultimate product afforded by radium is the metal lead. The 

 change, in fact, is one that is almost parallel with that noticeable 

 in the sudden passage, in the case of the elements, from metal to 

 non-metal — which is so remarkable. 



The discovery of radium has caught the popular fancy ; 

 naturally enough the astounding behaviour of the substance has 

 led to all sorts of expectations being formed of its potentialities 

 and the credulity of the public has been much imposed upon in 

 consequence ; there is little doubt that its curative virtues have 

 been grossly exaggerated and that it has been given a fictitious 

 value ; the day should be at hand when calmer reflection and 

 experience will show that the wish has too often been father to 

 the thought. As to the decompositions effected through the 

 agency of radium, of which we have often heard, all the infor- 

 mation the President of the British Association could give the 

 world last autumn was that experiments appeared to show that 

 under the influence of the energy set free from radium the metal 

 copper was converted partially into lithium and that the elements 

 thorium, titanium, zirconium and silicon were degraded by it 

 into carbon ; but chemists ask for more than " appearances " and 

 can only accept definitely established facts. 



So far as we know at present, the elements we have long 

 regarded as elements for the most part remain elements and 

 much as they were in Graham's days — yet in the interval 



