The expression "sequence of experiments" is a discreet but important element in the lexicon of 18th-century method. We propose here, through a few quotations, to identify its transformations and its main definitions in the life sciences in the mid-Enlightenment. This study is part of a broader framework that takes as its working hypothesis the presence of a pragmatic unity of method in the eighteenth century, manifested in the concrete practice of experimentation as well as in the mastery of the methodological vocabulary. In this respect, the study of the conceptions underlying the "sequence of experiments" is part of the investigation of a historically determined methodological language.