The extension of Black's method by the physicist Lavoisier led to the downfall of the purely qualitative theory of phlogiston, and gave to chemistry … - J. R. Partington

The philosopher Comte has made the statement that chemistry is a non-mathematical science. He also told us that astronomy had reached a stage when further progress was impossible. These remarks, coming after Dalton's atomic theory, and just before Guldberg and Waage were to lay the foundations of chemical dynamics, Kirchhoff to discover the reversal of lines in the solar spectrum, serve but to emphasize the folly of having "recourse to farfetched and abstracted Ratiocination," and should teach us to be "very far from the litigious humour of loving to wrangle about words or terms or notions as empty".

The blue dye indigo was obtained from the indigo plant by the Egyptians more than 4000 years ago. ...The famous and valuable "purple of Tyre" was perhaps first made in Crete in very early times... obtained at great cost... from tiny marine molluscs. ...The scarlet dye mentioned in the Bible was obtained from the kermes insect (hence the name "crimson").

Disagreement between theory and experiment has proved a most potent agent in broadening theoretical views, and in making clear the necessity for new concepts or hypotheses.