atomic theory
Preserved but no longer current.
The doctrine that all elemental bodies consist of aggregations of atoms (i.e. the smallest indivisible particles of the element in question), not united fortuit- ously, but according to fixed proportions. The four laws of Dalton are — constant pro- portion, reciprocal proportion, multiple pro- portion, and compound proportion.
Era: ca. 1898 (Victorian)
Sources & notes
Reproduced from Brewer’s Dictionary of Phrase and Fable (1898 edition, public domain; archive.org, retrieved 2026-07-31; OCR text, minor errors possible). Reflects the scholarship and attitudes of its era.
Common questions
What does “atomic theory” mean?
The doctrine that all elemental bodies consist of aggregations of atoms (i.e. the smallest indivisible particles of the element in question), not united fortuit- ously, but according to fixed proportions. The four laws of Dalton are — constant pro- portion, reciprocal proportion, multiple pro- portion, and compound proportion.
Is “atomic theory” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.