Unlike some other reproductions of classic texts (1) We have not used OCR(Optical Character Recognition), as this leads to bad quality books with introduced typos. (2) In books where there are images such as portraits, maps, sketches etc We have endeavoured to keep the quality of these images, so they represent accurately the original artefact. Although occasionally there may be certain imperfections with these old texts, we feel they deserve to be made available for future generations to enjoy.

Geology coalesced as a discipline in the early part of the nineteenth century, with the coming together of many strands of investigation and thought. The theme of experimentation and/or instrument-aided observation is absent from most recent accounts of that time, which rely on an admixture of theory and field observations, informed by close examination of minerals. James Hutton emerged as the person who had it right with suggestion of a central heat source for Earth, while Abraham Gottlob Werner and his Neptunist supporters were derided as being blinded by overarching belief, as opposed to sober application of observed facts. However, despite several claims that Hutton had won the day, primary literature from both England and the Continent reveals that the question was by no means settled for decades after Hutton derided information derived from "looking into a little crucible." This Special Paper makes the case that it was just those parameters of heat, pressure, solution, and composition discovered in the laboratory that prevented resolution of the overriding questions about rock origin.