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De Ortu & Causis Subterraneorum in five books has always been published in the company of other works. This is Its first appearance. The work consists of five books that contain Agricola's philosophical views on geological phenomena. The major portion of this text is a refutation of the geological ideas of the ancient philosophers, the alchemists and the astrologers. It displays Agricola's wide ranging knowledge of the classic authors and his ability in observation and dialectics. But it is when Agricola presents his own ideas that new territory was established in science. Book I is devoted to a discussion of the origin and distribution of ground water and mineralizing jucies. The last portion of this book and that of Book II consider the origin of subterranean heat that he attributes to burning coal and sulfur and the friction subterranean winds against the walls of caves. Book III is devoted to the origin of ore channels, while Books IV & V describe in summary the principal divisions of the mineral kingdom as given in De Natura Fossilium.