1920 in reference to a plan or system of school education designed by Helen Parkhurst, from Dalton, Massachusetts, U.S., where it was first adopted. For Daltonism (a reference to English chemist John Dalton), see color-blindness. Daltonian, in reference to Dalton's work, is attested by 1813.

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Definitions of Dalton from WordNet

Dalton (n.)
English chemist and physicist who formulated atomic theory and the law of partial pressures; gave the first description of red-green color blindness (1766-1844);
Synonyms: John Dalton