THE GREAT LONDON CHEMISTS 41 



safely conclude that it is not more than T ^ part of the 

 whole.' Here he was nearly right; about one per cent, 

 is actually left ; and it has been recently recognised as a 

 separate element, and named Argon. And still more 

 recently, the argon has been shown to contain a small 

 proportion of other gases, also elements, to which the names 

 helium, neon, krypton and xenon have been given. This 

 paper was the last on chemical subjects published by 

 Cavendish. 



These two men, Boyle and Cavendish, both rank as 

 great men. The first has been termed with justice f the 

 father of modern chemistry ' ; the second by ' weighing the 

 earth/ and by establishing the composition of water and 

 of air, has even more decided claims to that title. Each 

 was in advance of his age : Boyle by reason of his calm 

 philosophical spirit, and clear judgment; Cavendish in 

 the power he possessed, in an age of qualitative en- 

 deavours, of carrying out quantitative experiments with 

 the most refined accuracy, and of drawing from them 

 correct conclusions. 



II. DAVY AND GRAHAM 



Between a prospect over an extensive landscape, and a 

 retrospect in history, an instructive analogy may be 

 drawn. It is true that when the spectator is removed 

 from the object by a great distance, whether of time or 

 space, its appearance is ill-defined and hazy, as are to us 

 the personalities of the ancient Egyptians, Greeks, and 

 Arabians ; and just as the imagination supplies details to 

 the distant features of a landscape, details which may or 

 may not be in consonance with fact, so through the mists 

 of time we are apt to read into the writings of the 



