1 8 Meldrum, Development of the Atomic Theory. 



the 27th August, and Dalton's reply to Gough is dated 

 8th September. Thus Thomson's objections to the 

 theory, with Gough's in addition, may have compelled 

 Dalton to reconsider the matter. There was time for 

 reconsideration between the 8th September and the 14th, 

 the date of Dalton's decision to put the explanation of 

 the diffusion of gases on a new basis. 



The principal references connected ivitJi the theory of 

 mixed gases, 



1792. 



1. "On Evaporation," by Jean Andre Deluc. Phil. Trans.,. 



p. 400. 



1793- 



2. " jMeteorological Observations and Essays," by John 



Dalton. 



1799. 



3. " Experiments and Observations, to determine whether the 



quantity of Rain and Dew is equal to the quantity of 

 Water carried off by the rivers and raised by evaporation ; 

 with an Inquiry into the Origin of Springs," by John 

 Dalton. Read* March ist. Vwh. Manchester AlemoirSy 

 vol. 5, part 2, p. 346, 1802. (The footnote, p. 351, was 

 added after the paper was read.) 



1800. 



4. " Experimental Essays, to determine the Expansion of 



Gases by Heat, and the maximum of Steam or Aqueous 

 Vapour, which any Gas of a given temperature can admit 

 of; with observations on the common and improved 

 Steam Engines," by John Dalton. Read April i8th. 

 Never published in full ; see no. 8. 



* In ihe above list, " read '" means read before the Manchester Literary and 

 Philosophical Society. 



