After Fifty Years,So Much Learned,but So Much Still to Learn:On the Laws of Combining Gas Volumes and Atomic Heats

摘要

Gay-Lussacs law of integral volume proportions of combining gases（1808）and Dulong and Petits law of atomic heats（1819）provided the potential basis for deriving an unambiguous system of atomic weights and molecular formulas,but such a system achieved significant acceptance only after 1860.These two discoveries have been investigated and re-investigated innumerable times in the last fifty years,including by the present speaker forty years ago.One might well think that the early history of the atomic theory in chemistry had long since been squeezed dry of interesting new facts and insights.Nevertheless,a careful new study of these two famous landmarks一based solely on published sources一 offers new light,and also poses important new questions.This discussion provides an object lesson regarding the relative youth and promise of our field,fhere is still much to do,and much to learn.