Guillaume François Rouelle (, 15 September 1703 – 3 August 1770) was a French
chemist
A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe th ...
and apothecary. In 1754 he introduced the concept of a base into chemistry as a substance which reacts with an
acid
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a se ...
to form a
salt
Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quant ...
).
He is known as ''l'Aîné'' (the elder) to distinguish him from his younger brother, Hilaire Rouelle, who was also a chemist and known as the discoverer of
urea
Urea, also known as carbamide, is an organic compound with chemical formula . This amide has two amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest amide of carbamic acid.
Urea serves an important ...
.
He started a public course in his laboratory in 1738 where he taught many students among whom were
Denis Diderot
Denis Diderot (; ; 5 October 171331 July 1784) was a French philosopher, art critic, and writer, best known for serving as co-founder, chief editor, and contributor to the '' Encyclopédie'' along with Jean le Rond d'Alembert. He was a promi ...
Antoine-Augustin Parmentier
Antoine-Augustin Parmentier (, , ; 12 August 1737 – 13 December 1813) was a French pharmacist and agronomist, best remembered as a vocal promoter of the potato as a food source for humans in France and throughout Europe. His many other contri ...
The modern meaning of the word "base" and its general introduction into the chemical vocabulary are usually attributed to the French chemist, Guillaume-François Rouelle (1703–1770), who used the term "Base" in a memoir on salts written in 1754 (see The Origin of the Term "Base" by William B. Jensen). In this paper, which was an extension of an earlier memoir on the same subject written in 1744, Rouelle pointed out that the number of known salts had increased significantly during the 17th and early 18th centuries. This was due not only to the preparation of new salts, but also to an increasing ability to distinguish between sodium and potassium compounds, and to a generalization of the concept so as to include many substances, such as the alums and
vitriols
Vitriol is the general chemical name encompassing a class of chemical compound comprising sulfates of certain metalsoriginally, iron or copper. Those mineral substances were distinguished by their color, such as green vitriol for hydrated iron( ...
(i.e., sulfates), that had been previously excluded. In order to incorporate this extended concept of salt formation, Rouelle explicitly defined a neutral salt as the product formed by the union of an acid with any substance, be it a water-soluble alkali, a volatile alkali, an absorbent earth, a metal, or an oil, capable of serving as "a base" for the salt "by giving it a concrete or solid form".Source https://www.physicsforums.com/threads/etymology-of-base.543937/