Jean Beguin’s first chemical equation.
The slow process of differentiation, separation of chemical practice from that complex body of philosophical and scientific knowledge that goes by the name of alchemy, began in the 17th century. The field of application and development of chemistry was medicine. The main aim was the search for new drugs, especially of inorganic origin. Minerals were therefore the main source of employment. The medical practice in force was based on the Galenic pharmacopoeia and on the use of non-rational techniques of which the main one was bloodletting.
The power of the medical caste
The spread of the new medical chemistry encountered major obstacles from the powerful doctors’ guilds, especially the Faculty of Medicine of Paris. The Faculty of Medicine’s opposition to chemistry lasted a long time, and the teaching of chemistry was not permitted at the University of Paris until the end of the 17th century. The diffusion took place only through private lessons and courses, with the use of laboratories where the preparation of drugs was taught. In 1607 the first private chemistry lessons began to be held in Paris. They were open to the public, free, mostly attended by students of the Faculty of Medicine and apothecaries. The teacher was Jean Beguin (1550 – 1620), an iatrochemist, i.e. medical chemist.
A popular chemistry text
The teaching of Jean Beguin, which due to its content together with the objective of making knowledge accessible, contrasted with the secrecy of traditional medicine and its Galenic imprint, found strong hostility on the part of the powerful Faculty of Paris and the medical orders . Twice Beguin’s laboratory was burgled, many valuable preparations were destroyed and Beguin himself was beaten. To guide and orient his students, Jean Béguin published a small volume entitled Tyrocinium chymicum e naturae Fonte et manual experientia depromptum in 1610, which was very popular among chemistry students. From this revised and expanded volume with the addition of some chapters on general principles was born the first edition of his complete treatise, intended for the public which appeared in Paris in 1612 and should be considered the Editio Princeps of Beguin’s work.
A famous book
The first translation into French dates back to 1615, with the title Les Éléments de chimie, de maître Jean Béguin, aumônier du roi, and the first translation into English dates back to 1669. This text was the most popular classical work of the 17th century, since between 1612 and 1690, nearly 50 editions were published, mostly in Latin. Tyrocinium chymicum inaugurated a new genre of chemical works, the introduction to a wider and more interested public. This genre was among the prerequisites for the eventual emergence of chemical science. He intended his text to be useful from a practical point of view, therefore reporting clear and precise observations on chemical instruments and techniques with numerous definitions of technical terms.
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A chapter on Antimony
His text Tyrocinium Chymicum is divided into three books. In the second book there is a chapter, entitled De Calcinatione Antimoni, dedicated to antimony and its salts. After talking about various calcinations of antimony, in the paragraph Autre calcination d’antimoine, appelle poudre Emetic ou Mercure de vie describes the preparation of one of the most discussed and used drugs in iatrochemistry, antimony oxychloride SbOCl (Since the compound works as both an emetic and a laxative, it was originally used as a purgative). The drug was obtained from a double exchange reaction between mercury sublimate and the mineral stibnite.
Over the centuries, Antimony in its metal state and in its compounds has been a protagonist of alchemical practice first and of medical chemistry later
The Triumph of Antimony by Basilius Valentinus (1394-1450) translated edition of 1671
Frontispiece
The illustration depicts a personification of Antimony in the image of a woman sitting in a chariot. To her right is Mercury (mercury), driving the chariot is Vulcan, the same chariot is pulled by Saturn (lead), Diana (silver), Venus (copper) and Mars (the iron). Mercury and Antimony join their hands through a frame held by Fama, the goddess of fame. Note how mercury and antimony are close in the illustration and join hands: antimony was believed to have a mercurial nature
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The first representation of a reaction
Despite the fact that at the time there was no concept of element, compound and an objective criterion to define a chemical reaction, which involved the use of interpretations that belonged to abstract and imaginary categories, Jean Beguin provides an explanation of the reaction that we could define as revolutionary. He not only interprets the reaction correctly as a double exchange between two compounds, but he offers us the representation in a scheme that is virtually an equation in the modern sense. It is the first ever representation of a chemical reaction. It is one of those intuitions, often solitary, that fall on deaf ears, because they are well ahead of their time. He made no generalizations about chemical reactions. An entire century passed before such a generalization was advanced.
William Cullen (1710-1790) Scottish doctor and chemist, known for his innovative teaching methods, in his notes of lectures he gave at the University of Edinburgh, makes use of this scheme, which appears for the first time after that of Jean Beguin, in session 1756-7.
The PDF tells the historical context in which Jean Beguin worked and how he arrived, problematically for the first time, to understand the nature of a chemical reaction and write its equation.
