The present paper claims that M. S. Tswett’s chromatographic adsorption analysis, which today is a ubiquitous and instrumentally sophisticated chemical technique, was either ignored or outright rejected by chemists and botanists in the first three decades of the twentieth century because it did not make sense in terms of accepted chemical theory or practice. Evidence for this claim is culled from consideration of the botanical and chemical context of Tswett’s technique as well as an analysis of the protracted (...) debate over Tswett’s chromatographic analysis of chlorophyll between him and Leon Marchlewski, a noted chlorophyll chemist of the period. In this way, the paper expands and amends what it calls the ‘textbook story’ of the early history of chromatography, examples of which may be found in historical notes in many textbooks of chemical instrumental analysis and numerous short articles in chemistry journals. The paper also provides an accessible introduction to the early history of chromatography for historians of science likely to know little or nothing about it. (shrink)

We propose a new account of calibration according to which calibrating a technique shows that the technique does what it is supposed to do. To motivate our account, we examine an early twentieth-century debate about chlorophyll chemistry and Mikhail Tswett’s use of chromatographic adsorption analysis to study it. We argue that Tswett’s experiments established that his technique was reliable in the special case of chlorophyll without relying on either a theory or a standard calibration experiment. We suggest that (...) Tswett broke the experimenters’ regress by appealing to material facts in the common ground for chemists at the time. (shrink)