LECTURE ON DALTON 401 



many who surround me, it has been chiefly I may say almost 

 solely from unwearied assiduity ; this not so much from any 

 superior genius that one man possesses over another, but 

 more from attention to study and perseverance in the objects 

 before them that some men rise to a greater eminence than 

 others." 



If, as has been said, genius may be defined as " an infinite 

 capacity for taking pains," then Dalton was, unquestionably, 

 a genius. 



He was a follower of our great countryman, Newton. You 

 know that the old Greek philosophers put forward what they 

 called " an Atomic Theory of matter " that is to say, they 

 believed matter to be composed of very small indivisible 

 particles. Newton also was an atomist, but he did what no 

 one else had done he explained how those atoms are 

 attracted and repelled according to fixed laws, and then 

 explained the motions of the heavenly bodies. What Newton 

 did for astronomy Dalton did for chemistry. He said these 

 atoms exist ; by their coming together they produce chemical 

 change. But he did more, he said the atoms of the different 

 elements do not weigh the same. Each chemical element 

 consists of atoms uniform in weight but differing in this 

 respect from those of the other elements. He thus introduced 

 an idea which laid the foundation of our modern theory of 

 chemistry. John Dalton exhibits in high degree that power 

 of spiritual insight into the secrets of Nature which is 

 an essential attribute of the true philosopher. No one who 

 lacks the faculty of scientific imagination can wrest from 

 Nature her greatest, her sublimest, secrets. 



Perhaps Dalton's apparatus was the simplest anybody ever 

 employed ; and it is most remarkable, in reading his original 

 memoirs, to see with what simple apparatus he worked, and 

 from what simple materials he was able to draw such great 

 conclusions. I have before me some of Dalton's original 

 apparatus lent to me by the Literary and Scientific Society of 

 Manchester. It consists of a penny ink-bottle with a tube 

 fixed in the cork, and a couple of ordinary apothecaries' 

 scales. 



Here are also some weights he made. I found these 

 wrapped in a piece of paper on which was written, in his 

 beautiful hand, part of a note expressing his regret at not 

 being able to wait upon someone, on account of his going to 

 Liverpool with some friends to try the effects of travelling 

 by the newly made railway, between Liverpool and Man- 

 chester, on the occasion upon which Huskisson was killed. 



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