Calibrating Chromatography: How Tswett Broke the Experimenters’ Regress

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