12 Meldrum, Developme7it of tJic Atomic TJieory. 



common, is that each originated with Dalton. Thomson's 

 narrative and Henry's and Ransome's were based on 

 conversations with him, and there is no ground for 

 impugning their accuracy any more than his good faith. 

 The natural explanation of the existence of so many and 

 various accounts is that Dalton was simply deficient in 

 historical instinct. He did not perceive the difference 

 between describing the genesis of his theory and ex- 

 pounding the theory itself. 



A man who makes history, as Dalton did, need not be 

 a good historian. The account of the origin of the 

 chemical theory in his own handwriting is no more 

 satisfactory than the others which came from him at 

 second-hand. Apparently, Dalton never had in his mind 

 a precise view of how the theory developed, and when 

 invited to give one he produced, on the spur of the 

 moment, an account to which he did, or did not, adhere 

 on the next occasion. 



