THE SCIENTIFIC SPIRIT IN ENGLAND. 



245 



of modern chemistry, who next to Lavoisier did more 

 than any one else to introduce into this science mathe- 

 matical ideas, John Dalton, grew old and infirm before 

 his countrymen sufficiently recognised and honoured him. 

 Deprived of all but the very meanest apparatus for the 

 proofs of his theories, and yet able to do what he did, 

 what might not such a genius have accomplished if he 

 had possessed the means of a Gay-Lussac or a Eegnault ? ^ 



18. 

 Dalton. 



in 1814, has been well established. 

 See Benfey, ' Geschichte der Sprach- 

 wissenschaf t ' (Miinchen, 1869, p. 

 729). Bunsen pronounced his ver- 

 dict in his well - known woi'k, 

 ' Egypt's Place in Universal His- 

 tory,' published in 1845-57. On the 

 whole, the words of Peacock, ' Life 

 of Dr Young' (London, 1855), p. 

 472, are still correct : " His scien- 

 tific works were rarely read and 

 never appreciated by his contem- 

 poraries, and even now are neither 

 sufficiently known nor adequately 

 valued ; whilst if justice was award- 

 ed more promptly and in more lib- 

 eral measure by his own countrymen 

 to his hieroglyphical labours, these 

 also were singularly unfortunate, as 

 far as concerned the general diffu- 

 sion of his fame, by coming finto 

 collision with adverse claims, which 

 were most unfairly and unscrupu- 

 lously urged in his own age, and 

 not much less so by some distin- 

 guished writers in very recent 

 times." 



1 John Dalton (1766 - 1844), a 

 native of Cumberland, spent the 

 greater part of his life in teaching 

 elementary mathematics at Man- 

 chester, first at a college and then 

 privately. In 1801 he propounded 

 the law known under the joint name 

 of Dalton and Gay - Lussac (who 

 stated it six months later). In the 

 years immediately following he ela- 

 borated his atomic theory, which 

 was to account for the existence of 



those definite quantitative relations 

 between the chemical constituents 

 of bodies known already to Richter. 

 It was published in 1805. But the 

 man who did most to make known 

 to chemists the ideas of Dalton was 

 Thomas Thomson (1773-1852), Pro- 

 fessor of Chemistry at Glasgow, who 

 in 1807, in the -Srd edition of his 

 ' System of Chemistry,' gave an ac- 

 count of the atomic theory based 

 upon communications of Dalton. 

 Two memoirs published in the 

 ' Philosophical Transactions ' of 

 1808 one by Thomson on "Oxalic 

 Acid," and one by Wollaston on 

 "Super- Acid and Sub- Acid Salts" 

 pointed to the great importance 

 of the atomic theory, which (Wol- 

 laston prophetically added) would 

 not stop short witli the determin- 

 ation of the relative weights of 

 elementary atoms, but would have 

 to be completed by a geometrical 

 conception of the arrangement of 

 the elementary particles in all the 

 three dimensions of solid exten- 

 sion. The real merit of having ex- 

 perimentally proved the theory of 

 Dalton belongs to Berzelius, whereas 

 Sir Humphry Davy opposed it for 

 many years after it had been ac- 

 cepted abroad. Dalton himself by 

 no means followed the development 

 which his ideas underwent at the 

 hands of others. For example, he 

 opposed Gay-Lussac's law of vol- 

 umes. He was on the whole more 

 successful in working out his own 



