In the received history, chemistry began to transform from cookery to science toward the end of the 17th century with the introduction of sustained systematic experiment, color indicators, and the mechanical philosophy. Robert Boyle is usually considered the chief promoter of these improvements. In fact, the mechanical philosophy played a marginal part in the development of chemistry during Boyle's time and he was too eager an alchemical adept to establish the cooperative enterprise that precipitated modern chemistry. While Boyle sought the philosopher's stone, members of the Paris Academy of Sciences set the course of modern chemistry by developing a style of thorough, repeated, systematic experimentation and accurate measurement that resemble the practices that historians customarily credit to the late 18th century. The present paper makes this case by reconstructing the Academy's program of experiments to determine the constituents of chemical “mixts,” mainly parts of plants, as recorded in the laboratory notebooks of Claude Bourdelin. These experiments typically employed maceration or a similar technique to “loosen” the ingredients of the substance under investigation followed by distillation at various temperatures. The academicians tested the several fractions of distillate thus produced with many reagents, including color indicators of acidity. Some of the preliminary steps lasted for weeks, and some of the distillations for days. To reassure themselves that their procedures did not destroy or discard important constituents, they weighed both raw materials and end products and totted up the sum in a manner worthy of Lavoisier.