It's the right idea, but not the right time.

He also rediscovered George Hadley's theory of atmospheric circulation (now known as the Hadley cell) around this time. Public and personal life
Before he had propounded the atomic theory he had already attained a considerable scientific reputation. It has been proposed that this theory was suggested to him either by researches on ethylene (olefiant gas) and methane (carburetted hydrogen) or by analysis of nitrous oxide (protoxide of azote) and nitrogen dioxide (deutoxide of azote) both views resting on the authority of Thomas Thomson.

John Dalton FRS (6 September 1766 – 27 July 1844) was an English chemist meteorologist and physicist.