History of Geology - 18th Century

18th Century

From this increased interest in the nature of the Earth and its origin, came a rise in the interest of minerals and other components of the Earth’s crust. Moreover, the increasing commercial importance of mining in Europe during the mid to late 18th century made the possession of accurate knowledge about ores and their natural distribution essential. Scholars began to study the makeup of the Earth in a systematic manner, with detailed comparisons and descriptions not only of the land itself, but of the semi-precious metals that had such great value. For example, in 1774 Abraham Gottlob Werner published the book Von den äusserlichen Kennzeichen der Fossilien (On the External Characters of Minerals), which brought him widespread recognition because he presented a detailed system for identifying specific minerals based on external characteristics. The more efficiently that productive land for mining could be found and that the semi-precious metals could be identified, the more money that could be made. This drive for economic success fueled geology into the limelight and made it a popular subject to pursue. With an increased number of people studying it, came more detailed observations and more information about the Earth.

During the eighteenth century, the story of the history of the Earth; namely the religious concept versus factual evidence once again became a popular discussion in society. In 1749 the French naturalist Georges-Louis Leclerc, Comte de Buffon published his Histoire Naturelle in which he attacked the popular Christian concepts of Whiston and other Christian theorists on the topic of the history of Earth. From experimentation with cooling globes, he found that the age of the Earth was not only 4,000 or 5,500 years as inferred from the Bible, but rather 75,000 years. Another individual who attributed the history of the Earth to neither God nor the Bible was the philosopher Immanuel Kant who published this concept in 1755 in his Universal Natural History and Theory of Heaven (Allgemeine Naturgeschichte und Theorie des Himmels). From the works of these educated men, as well as others, it became acceptable by the mid eighteenth century to question the age of the Earth. This questioning represented a turning point in the study of the Earth. It was now possible to study the history of the Earth from a scientific perspective rather than a religious one.

With science as a driving force behind the investigation of the Earth's history, the study of geology could now become a distinct field of science. First, the terminology and definition of what geological study consisted of had to be determined. The term geology was first used professionally in publications by two Genevian naturalists, Jean-André Deluc and Horace-Bénédict de Saussure. Geology was not well received as a term until it was used in the very popular encyclopedia, the Encyclopédie, published in 1751 by Denis Diderot. Once the term was coined as the study of the Earth and its history, geology slowly became a more prevalent and recognized science of its own standing that could be taught as a field of study at educational institutions. In 1741 the most well-known institution in the field of natural history, the National Museum of Natural History in France designated the first teaching position specifically for geology. This was an important step in the further development of geology as a science and in the recognition of the importance of widely distributing this knowledge.

After the designation of geology as a specific field of study in an institution, this subject flourished in educated society. By the 1770s two feuding theories with designated followers were established. These contrasting theories explained how the rock layers of the Earth’s surface had formed. The German geologist, Abraham Werner proposed the theory that the Earth’s layers, including basalt and granite, had formed as a precipitate from an ocean that covered the entire Earth, referring to the Deluge. Werner’s system was influential and those that believed his theory were known as Neptunists. The Scottish naturalist, James Hutton, argued against the theory of Neptunism. Hutton proposed the theory of Plutonism; the Earth formed through the gradual solidification of a molten mass at a slow rate by the same processes that occurred throughout history and continues in present day. This led him to the conclusion that the Earth was immeasurably old and could not possibly fit within the limits of the inferences from the Bible. Plutonists believed that volcanic processes were the chief agent in rock formation, not water from a Great Flood.