4 MeLDRUM, Development of the Atomic Theory. 



to devise the latter in the space of a month, simply because 

 he had the former to work upon. 



The close resemblance between the two theories, both 

 in principle and results, puts it beyond doubt that Dalton 

 was forestalled by William Higgins. Plumphry Davy, 

 in his Bakerian Lecture of the year 1810, was the first to 

 draw attention to Higgins' claims. The terms in which 

 he did so are remarkably decided, and such as to throw 

 him into almost too pronounced antagonism to Dalton. 

 " In my last communication to the [Royal] Society, I 

 have quoted Mr. Dalton as the original author of the 

 hypothesis that water consists of i particle of oxygen and 

 I of hydrogen, but I have since found that this opinion is 

 advanced in a work published in 1789 — 'A Comparative 

 View of the Phlogistic and Antiphlogistic Theories,' by 

 William Higgins. In this elaborate and ingenious per- 

 formance, Mr. Higgins has developed many happy 

 sketches of the manner in which (on the corpuscular 

 hypothesis) the particles or molecules of bodies may be 

 conceived to combine ; and some of his views, though 

 formed at this early period of investigation, appear to me 

 to be more defensible, assuming his data, than any which 

 have been since advanced." - 



The only public notice wliich Dalton himself took of 

 Davy's words was to publish a paper in which he was 

 careful not to name Higgins. The date of Davy's lecture 

 was 15th November, and of Dalton's paper 19th December. 

 He contended that the use of the word particle, as opposed 

 to atom, was a matter of great consequence — a contention 

 which was quite unworthy of him,'' 



^Bakerian Lecture, 15th Nov., 1810. PliiL Trans., iSii, p. 15 ; Davy's 

 Works, vol. 5, p. 3.^6. 



^ Nicholson'' s Jotirn., vol. 28. p. 81, 181 1. 



