The Scottish naturalist James Hutton (1726-1797), the founder of modern geology, is best known for his Theory of the Earth.
James Hutton was born in Edinburgh on June 3, 1726. He entered Edinburgh University in 1740 to study the humanities, but he developed an intense and long-lasting interest in chemistry. At 17 Hutton was placed as an apprentice in a lawyer's office; however, performing chemistry experiments during office hours led to his dismissal, and he then chose medicine as a profession. For 3 years he pursued medical studies at Edinburgh University in spite of the fact that no degree of medicine could be obtained from that institution. Therefore, in 1747 he went to Paris to study chemistry and anatomy. He received a medical degree at Leiden in 1749.
Back in London, Hutton realized that even medicine would not give him sufficient spare time for his scientific interests. He therefore abandoned medicine for agriculture. In 1752 he went to a farm in Norfolk, where the scenery apparently turned his mind to mineralogy and geology.
In 1754 Hutton visited Flanders allegedly to compare husbandry methods with those practiced in Norfolk. Actually he spent most of his time making geological observations later to be included in his Theory of the Earth. At the end of the year he settled down at his family property in Berwickshire, where he managed a farm according to the most scientific methods. In 1768 he abandoned his country life and settled in Edinburgh, spending all his time on scientific studies. His interests, however, were by no means confined to geology, for he published treatises on physics and metaphysics and investigated all branches of science except mathematics.
The spectacular geological features around Edinburgh provided Hutton with numerous fundamental observations to combine with his broad knowledge of many parts of Great Britain. Eventually he was led to formulate a definite theory, or system, of the earth, and although he had discussed it at length with his friends, he did not write it down until he was persuaded to address in 1785 one of the first meetings of the newly founded Royal Society of Edinburgh. The full text was published in the Transactions in 1788 under the title "Theory of the Earth; or, An Investigation of the Laws Observable in the Composition, Dissolution and Restoration of Land upon the Globe." The paper attracted little attention, perhaps because of its misleading title of "Theory" and its publication in the transactions of a learned society which had just been founded. However, when the paper was criticized in 1793, Hutton revised and developed his theory in greater detail. The result was the Theory of the Earth, with Proofs and Illustrations (2 vols., 1795). A projected third volume remained incomplete and was published by the Geological Society of London in 1899.
In Hutton's opinion, the purpose of geology is first to collect objective data by observing the earth's crust and second to interpret the evidence with a minimum amount of imagination, rather than to begin with an artificial hypothesis and then attempt to fit the observations into a rigid theoretical framework. Hutton's theory evolved in such a natural fashion from his observations that it achieved the prerequisite of involving very little speculation. His basic assumption is that the past history of the globe should be interpreted in the light of what is happening today or has happened in recent times. This dominant idea that the present is the key to the past is so commonplace in modern geological thinking that one often fails to fully appreciate the genius of the man who first formulated it in modern times.
Hutton first turned his attention to sedimentary rocks, observing that they consist of debris of older rocks. He drew a parallel between such rocks and present-day marine deposits, comparing conglomerates with gravels, sandstones with sands, limestones with accumulations of organic debris, and shales with silts and muds. From the wide distribution of these beds—which form the continents—he understood that they could only have been deposited in the sea. Hutton's first conclusion was that the continents consisted of indurated sediments which, eroded from some preexisting emerged land, had been spread in strata over the sea floor. Since all these sedimentary rocks were originally deposited as soft sediments but appear today as indurated rocks, he attributed this change to the combined action of pressure and subterranean heat.
Hutton's next problem was to explain how beds originally deposited in a horizontal fashion on the sea floor could occur in mountains such as the Alps, tilted, ruptured, and contorted in a spectacular fashion. Hutton understood that such occurrences resulted from powerful revolutions which at different times in the past seem to have affected the entire earth's crust. After having demonstrated the existence of episodes of large-scale deformation which had uplifted the sea bottom with its indurated sediments and folded them in a complex manner to build the existing continents, he investigated the possible cause of these processes. He assumed the existence of forces acting vertically and upward which were probably related to deep-seated reservoirs of heat. The action of these vertical forces interfering with gravity and the resistance of the rocks would create a lateral and oblique component responsible for the contortions of the beds.
Hutton considered volcanoes as safety valves through which some of the earth's internal heat could escape, but he understood that the heat was not due to the combustion of coal seams or the oxidation of pyritic shales, as believed for a long time, but to a deep-seated and molten mass. By means of this concept, Hutton attempted to explain the origin of the various types of nonstratified rocks, either massive or in veins, which he had observed in different places. He called them whinstones (basic rocks, including basalts), porphyries, and granites, and interpreted them as material that once had been in a molten condition and subsequently had been injected upward during the great disturbances of the earth's crust.
Most of the modern ideas on geomorphology are to be found in the Huttonian theory, including the importance of the erosion and transportation power of mountain glaciers. However, these concepts were ignored or even rejected for many years.
Hutton died on March 26, 1797. His Theory of the Earth is marred by a rather obscure style and defective organization. One of his friends, John Playfair, the mathematician and natural philosopher, was able to give the work a well-organized and elegant presentation, combined with a series of personal comments, under the title Illustrations of the Huttonian Theory of the Earth (1802).
A modern biography of Hutton, including excerpts of his major works, is Edward Battersby Bailey, James Hutton: The Founder of Modern Geology (1967). Other accounts of Hutton's life and contribution to geology are in Sir Archibald Geikie, The Founders of Geology (1897; 2d ed. 1905); Karl Alfred von Zittel, History of Geology and Palaeontology to the End of the Nineteenth Century (1899; trans. 1901); and F. D. Adams, The Birth and Development of the Geological Sciences (1938).