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La Lettre
© B.Eymann - Académie des sciences
Jacques Livage
Member of the Académie des Sciences, Honorary Professor at the
Collège de France
Chemistry, the art of transforming matter, played a key
role in the history of humanity. With every progress
achieved in extracting metals from their ores, another
stage was reached in our development. Indeed, we have
gone from the Age of stone to that of copper, then bronze
and iron. Today, high-temperature silica reduction leads
to the formation of silicon, which is at the origin of the
development of all modern electronics.
Chemical Arts
Curiously enough, although "chemical arts" had been practised since earliest antiquity, chemistry as a
science only rose in the late 17
th
century. As soon as it was created, in 1666, the Académie des Sciences
appointed two chemists, Claude Bourdelin and Samuel Cottereau du Clos. As a matter of fact, neither
was really a chemist: the former was an apothecary to the Duke of Orleans, and the latter was an ordinary
physician to Louis XIV. At the time, chemistry was mostly about extracting active principles from plants or
analyzing mineral water: it was part of medicine and pharmacology.
For chemistry, the science of matter, there was still a fundamental question to answer in the early 17
th
century: what is matter, what is it made of? The hypotheses propounded by the Greek philosophers of
antiquity were still predominating. Democritus claimed that matter was composed of tiny grains (atoms),
whereas Empedocles, Aristotle and Plato asserted that it was made of four elements: water, air, fire and
earth – a model that alchemists would apply to their own ambition, transforming metals into gold... In the
18
th
Century, Ernst Stahl, to explain combustion, was still resorting to the element of "flame": it was the
"phlogiston" theory, superseded by Lavoisier when he highlighted the role oxygen played in combustion
phenomena. The publication of the Elementary Treatise of Chemistry, in 1789, marked the birth of a
universal language - chemical nomenclature - that would be used by chemists worldwide! Shortly afterwards,
Chemistry, the science of matter:
to understand and create!