SOME CONSEQUENCES OF GRAHAM'S WORK 601 



elusion that the atoms of the radio-active elements are built 

 up, in part at least, of helium atoms. It is certainly very 

 remarkable and may prove of great significance that helium, 

 which is regarded from the ordinary chemical standpoint as 

 an inert element, plays such an important part in the constitu- 

 tion of the atoms of uranium, thorium and radium." 



Moreover, while writing this account, I have been sur- 

 prised to find a very remarkable communication by the late 

 Professor Johnstone Stoney (in his day one of the highest 

 authorities on questions of molecular physics) published in 

 the Chemical News, in 1895, 1 the week after a full account 

 was first given of argon. Professor Johnstone Stoney suggested 

 that the properties of argon are compatible with the view 

 that this " element " is a compound of the type of a paraffin 

 hydrocarbon, such as octane, derived from one of the un- 

 known elements falling between hydrogen and lithium. 



I therefore do not stand quite alone as a heretic and 

 should find some companions at the stake. 



I will add, in conclusion, that I have advisedly abstained 

 from discussing the sub-atomic, electrical (electronic) hypothesis 

 of the constitution of matter which is now under consideration. 

 Frankly, I am not yet satisfied that this stands on a valid 

 basis of ascertained fact, my opinion being that the problem of 

 electrical conductivity in gases has not been studied with all 

 the precautions and the thoroughness that is necessary to 

 justify us in accepting the far-reaching conclusions physicists 

 have based upon their observations. 2 The occasion is one 

 on which it is incumbent on us to use a variety of hypotheses. 



1 Vol. lxxi. p. 67. 



2 I have no wish to minimise the value of the observations and of the 

 arguments that are based upon them. But not only is it easy to be possessed 

 by one idea — there is also the difficulty, we must all admit, in which we are 

 placed, that of understanding one another. At the present day, in all dis- 

 cussion of the intricate problems to which workers are devoting their attention 

 in the various fields of scientific inquiry, the difficulty arises that we do not 

 as yet— and perhaps cannot — see eye to eye ; there is no doubt that various 

 types of mind are required to appreciate the various points of view from 

 which the problems can be considered and that it is rare to find in one mind 

 powers of appreciation sufficiently varied to comprehend all the possible 

 issues. In the course of my career I have only met one man who has 

 appeared to me to be capable of appreciating the several points of view 

 of different types of workers and of acting as arbitrator in cases such 

 as that under consideration— the late Professor Fitzgerald of Dublin. He could 



