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Giraud-Soulavie studied at Saint Nicolas College from 1771 to 1773.
Giraud-Soulavie studied at Saint Nicolas College and the Holy Spirit Seminary from 1771 to 1776.
Ordained in 1776, Giraud-Soulavie was one of the many philosophical abbés and pamphleteers active before the Revolution. He became an early member of the Jacobin Club, supported the Civil Constitution of the Clergy in 1790, and served as the diplomatic resident of the First Republic in Geneva from 1793 to 1794. After 1794 he devoted himself to the writing and editing of memoirs concerned with the history of France. Perhaps best known is his Mémoires historiques et politiques du règne de Louis XVI, which, like his other works, remains difficult to evaluate for its accuracy and historical significance.
Giraud-Soulavie’s scientific activities occupied a relatively short period of his life. A self-taught amateur, he was widely read and spent some time during the 1770s exploring the volcanic regions of Vivarais and Velay. On his arrival at Paris in 1778, his geological views had already been formulated. After additional field trips, he returned to Paris in 1780, established permanent residence there, and became a familiar figure at several salons.
Giraud-Soulavie published numerous studies on natural history, his major work being a Natural History of Southern France in seven volumes. In this book he estimates the age of the Earth to several hundred million years, the most enormous figure advanced so far. Dividing the history of sedimentary lands into five epochs, he sketches a transformist theory of flora and fauna which, under the influence of the environment, become more complex and transform. In 1784, the Church, considering that his work contradicts the Bible, forbade publication of the last two volumes. A great collector of manuscripts and prints, Giraud-Soulavie abandoned publishing of scientific works from 1785, and then of collections and memoirs from 1799.
During the French Revolution, having embraced new ideas, Giraud-Soulavie became a member of the Society of Friends of the Constitution and published political articles in the various newspapers.
Beginning with the then-common idea that most sedimentary formations had been deposited by a universal, gradually diminishing ocean, Giraud-Soulavie stressed and developed the principle of superposition. He used superposition not only to determine the relative ages of strata, but he also attempted to correlate age with fossil remains. He argued that the oldest Strata also contain the largest proportion of extinct species, while the youngest show a predominance of forms with living analogues. He then attempted to work out local geochronology for Vivarais by taking note of those sedimentary formations in which volcanic debris could be found. These observations and ideas were expressed on geological maps of his own design, using combination symbols, hachures, and color.
Soulavie’s geological ideas were actually less clear and consistent than is suggested by any one of his publications. Although he always insisted dial volcanic activity was more important and widespread than some contemporaries believed, he was vague and contradictory about the source of volcanic heat. On occasion, he seems to have held Neptunist views of the nature of the earth’s core and oldest formations; elsewhere, however, he discussed the probable existence of a central heat within the earth. In different portions of the Histoire naturelle, he emphasized both the extinction of species and the likelihood that seemingly extinct species had merely migrated to warmer climates.
Jean-Louis Giraud-Soulavie was a member of the Royal Academy of Inscriptions and Literature and Russian Academy of Sciences.
Giraud-Soulavie married to Marie-Madeleine, daughter of the lawyer and notary Urbain Mayaud and Madeleine Tarbouillet, in 1792.