Jean Andre Deluc


Jean Andre Deluc was a Swiss meteorologist, physicist, and geologist. Despite also being a physicist though, the main interests of the scientist were meteorology and geology and even famous geologist Georges Cuvier mentioned him to be an authoritative figure when it came to geological concerns. “Lettres physiques et morales sur les montagnes et sur l’histoire de la terre et de l’homme” was a 6-volume publication back in 1778-1780 by Jean Andre Deluc which he made in dedication to Queen Charlotte. He was also a scientist who had made contributions to instruments used for scientific measurements.

Early Life and Educational Background

His birthplace was Geneva, Switzerland although he traces his roots from his family whose origins were from the town of Lucca, Italy. Françoise Huaut, Deluc’s mother, was married to Jacques-François Deluc who was then the main author of publications which refuted Mandeville as well as other writers of rationalism. Jacques-François Deluc had given Jean Andre Deluc a great education which ad first focused on natural science and mathematics. For his mathematics classes, he had been a pupil of Georges-Louis Le Sage.

Because of his competence especially in the field of mathematics, he had then involved himself with affairs related to commerce which became a major part of his years—around 46 years of it. It had only been interrupted by some business journeys which took him to other countries, and some scientific trips to the Alps.

Together with Guillaume-Antoine, his brother, they were gradually able to collect, his very own specimen for mineralogy as well as natural history. This same collection had started a kind of museum which was later on enriched by a lad referred to as J. André Deluc, his nephew, who also happened to be a writer in the field of geology.

Career and Other Engagements

There was a time when Jean Andre Deluc had taken a prominent role in political engagements. In 1768, Deluc had been successful in gaining the friendship of the duc de Choiseul when he was in Paris. Four years later, he was able to become one of the members of Geneva’s Council of Two Hundred.

It was in 1773 though that a change in the field of commerce which had made it necessary for Deluc to move from his hometown. He was only able to go back to his hometown after a couple of days, and despite this change which others may have seen as a sad one, this had made him become freer to pursue his scientific endeavours. He moved to England that same year and was made as one among the Royal Society’s fellows and was even appointed as the reader to the Queen Charlotte. He was able to hold this position for 44 years and it had given him both enough time on his hands for personal scientific pursuits as well as income.

Scientific Interests and Contributions

The main interests of Jean Andre Deluc included meteorology and geology. He was able to publish several volumes on findings about geology he was able to record during his travels in Europe in 1810, England in 1811, and also in France, Germany, and Switzerland in 1813.

One of his more prominent theories had been on how heat disappeared when ice was being thawed—and this happened around the same period when Joseph Black had made this the basis of his personal hypothesis on latent heat. Deluc had ascertained how waster was denser when it was at 40 °F and not while it was at its freezing temperature. He had been the proponent of this theory, and later on it was revived by scientist John Dalton

Apart from his publication which was dedicated to Queen Charlotte, he had “Lettres sur l’histoire physique de la terre” in 1798 which was written to Johann Friedrich Blumenbach which contained the essays on General Principle of Morality.

When he had his time to pursue his scientific interests, he had dedicated time to perfecting his inventions which were instruments for scientific measurements. He was able to devise a portable kind of barometer which can be used for geological expeditions. His two-volume publication called “Recherches sur les modifications de l’atmosphère” was published in 1772 and the second edition in 1784 and contained experiments regarding moisture as well as evaporation and indications of thermometers and hygrometers. He had even used the barometer for determining heights.

He even had a publication called The Philosophical Transactions which was his accounts on a new kind of hygrometer that resembled a kind of mercurial thermometer equipped with a bulb made of ivory that expanded through moisture which would then cause the descent of mercury. He was the one who had given the first set of correct rules to measure heights using a barometer. It was also he who argued using mercury rather than alcohol when it came to making thermometers.

Personal Life and Latter Years

He had been a religious man, and apart from his being involved with scientific studies h had done on his own, the latter years of Deluc’s life was dedicated to theological matters. He even had a controversial experience with Hutton which expressed how although Deluc had never argued Hutton’s being an atheist, he had accused the man of his failure to properly counter atheism.

During his years he had collected Scriptural data which he had also considered as descriptions of the world’s history. He had even explained how the first six days of Creation as accounted in the Bible had been epochs that had preceded the present state of his time in his work called “Lettres physiques et morales.” In this work he had also attributed the great deluge as the reason of the filled up cavities inside the earth.

He had also been given the leave to explore France, Switzerland, Germany and Holland. He had even been distinguished at the University of Göttingen with honorary professorship of philosophy and geology. He had also been one trusted correspondent of the French Academy of Sciences as well as other learned and esteemed societies. He had 70 years of research and scientific works before he died in Berkshire, England in November 1817. In honour of his scientific efforts, there is an impact crater on the surface of the moon which had been named as “Deluc.”