This book is one of the first applications of a functional approach to language across time. It first summarizes and evaluates previous studies of the development of scientific language, including HallidayOCOs exploration of this fascinating topic. It then traces the development of scientific writing as a genre, in terms of its linguistic features, from ChaucerOCOs Treatise on the Astrolabe (the first technical text written in English) almost to the present. It goes on to consider texts by major scientists of the late seventeenth century, and then analyses and discusses a corpus of texts taken from the Philosophical Transactions of the Royal Society, covering the period 1700 to 1980."