Geoffrey Blumenthal (University of Bristol), James Ladyman (University of Bristol)
There are two particularly noteworthy examples in late eighteenth-century chemistry of experiments that were explicitly taken by participants on different sides to be turning points in theory choice. This paper argues that in both cases the experiments were "crucial" in the sense of deciding in favour of one among selected testable hypotheses, and establishing its approximate truth in the terms of the contemporary debate. The views of various influential philosophers of science are reviewed in the light of these cases. It is argued that the crucial experiments in question took considerable practical and intellectual ingenuity to engineer and that they are not typical of how science progresses, but nonetheless important when they can be found.
