5Q2 THE POPULAR SCIENCE MONTHLY 



devised by him are first found in his note-book under the date Sep- 

 tember 6, 1803; and, under the same date there is a table of atomic 

 weights, showing that, by this time, he had grappled with the funda- 

 mental problem — that of fixed " relative weights of the ultimate par- 

 ticles of bodies." For unknown reasons Dalton appended it, in a some- 

 what different form, to a paper •' On the Absorption of Gases by 

 Water," read before the Manchester Society in October, 1803, but not 

 published till November, 1805. The table was added during the interval 

 between presentation and publication. The summer of 1804, as Dalton 

 himself tells us, was the crucial period of the investigation. The first 

 part of the first volume of the " New System of Chemical Philosophy," 

 published in 1808, gives the mature theory, while the second part of 

 1810 describes the chemical elements in detail. Dalton was now forty- 

 four. And it is significant that, although he had lectured twice at the 

 London Eoyal Institution, and in Glasgow and Edinburgh as well, the 

 French Academy of Science recognized his merits six years 5 before any 

 native body. In 1822, Dalton being fifty-six, the Royal Society hon- 

 ored itself by his election. Another decade elapsed ere Oxford conferred 

 her D.C.L., on the occasion of the second meeting of the British Asso- 

 ciation, and he was sixty-eight when Edinburgh enrolled him among her 

 honorary doctors. In 1833, the government took note of his services, 

 and he received a civil list pension, increased afterwards in 1836, when 

 the announcement was publicly made under dramatic circumstances by 

 Sedgwick, at the Cambridge meeting of the British Association. " The 

 imagination may picture, if it can," writes Eoscoe, " the feelings of the 

 son of the poor Eaglesfield handloom weaver as he sat in the Senate 

 House of the University of Cambridge listening to this eulogium — the 

 observed of all observers." 6 As Sedgwick remarked in his striking 

 speech, " without any powerful apparatus for making philosophical 

 experiments — with an apparatus, indeed, many of them might think 

 almost contemptible — and with very limited external means for em- 

 ploying his great natural powers, he had gone straight forward in his 

 distinguished course, and obtained for himself, in those branches of 

 knowledge which he had cultivated, a name not perhaps equaled by 

 that of any other living philosopher of the world." 7 Evidently, then, 

 Dalton wrought under grave disadvantages. What were they? 



We would all agree, I take it, that certain results of human activity 

 must remain intimately personal, and that, as a consequence, they must 

 vary from age to age, or diverge even among different peoples in the 

 same epoch. Art and poetry, religion and, possibly, some portions of 

 philosophy, can not well escape these very subtle contrasts. But, with 



8 Cf. " John Dalton and the Rise of Modern Chemistry," Sir Henry E. 

 Roscoe, p. 175. 



"Ibid., pp. 204, 205. 



' Ibid., p. 203. 



