588 SCIENCE PROGRESS 



than is afforded by a recent attempt to reduce the lives of Great 

 Men to rule. 



i. The Nature of Elements 



Graham was a believer in the essential unity of matter. 

 Five-and-twenty years ago, Thorpe could only assure you that 

 although the elements remained elements, chemists were with 

 Graham in spirit; taking all the evidence into account, he said : 

 11 The mind insensibly appeals to the principle of continuity and 

 refuses to believe that the seventy and odd ' elemental ' forms 

 to which our processes of analysis have reduced all the kinds 

 of matter we see around us differ in essence from bodies which 

 are known to be compound." 



But the world moves rapidly in these times — we are now 

 returned to the days of Alchemy and talk glibly of the 

 transmutation of elements, though we concern ourselves rather 

 with destruction and the degradation of the expensive into the 

 valueless than with the conversion of base into noble. It may 

 be worth while to consider the nature of the evidence and in 

 so doing to exercise some of the care which, we are told, is 

 obvious in Graham's work. 



About the year 1894 Lord Rayleigh, in studying atmospheric 

 nitrogen, came to the conclusion that it was heavier than it 

 should be if it consisted of the pure gas : in collaboration with 

 Professor Ramsay, he subsequently separated from air the 

 element argon, a gas which is heavier than nitrogen in the 

 proportion of about 20 to 14. Soon afterwards Ramsay 

 discovered the element helium in the mineral Cleveite ; at a 

 later date he separated three other new gases from air, neon, 

 krypton and xenon. Except argon, of which air contains 

 about 1 per cent., these gases are present in extraordinarily 

 small proportions : 



Molecular Volume in 



weight. 100 volumes of air. 



Helium 4 o , ooo4 



Neon 20 o"ooi2 



Argon 40 0937 



Krypton 83 0-009 



Xenon 130 o'ooi 



The new elements are all worthless, chemically speaking, 

 being uniformly irresponsive to all attractions the chemist can 

 offer them. There is only one thing we can do with them — we 



