Art du Coutelier, Tire-Tête de Gregoire et celui de Mr Levret.

Denis Diderot (1713 - 1784)

Diderot was the most prominent of the French Encyclopaedists. The Encyclopédie is the most famous publications representing the thought and ideals of the Enlightenment. The Encyclopédie's aim was "to change the way people think". Diderot wanted to incorporate all of the world's knowledge into the Encyclopédie and it was the first general encyclopaedia to describe the mechanical arts. It attempted to collect and summarise human knowledge in a variety of fields and topics, including philosophy, theology, science and the arts. The Encyclopédie was controversial for reorganising knowledge based on human reason instead of by nature or theology.

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Jean-Jacques Perret (1730 - 1784)

Perret was the son of a poor cutler and destined to follow in his father's business. At the age of 12 , at the end of his apprenticeship, he left for a tour of France, traveling through the main towns of the south, traveling on foot, with the ambition of going to Paris, after having made his hand in the provinces. When he arrived, aged 15 , he went to the most skilled and renowned master cutler in the capital. The foreman, of the workshop who were made up exclusively of experienced workers, refused to test him. He then went to beg to the boss himself who was a maker of surgical tools, a specialty not familiar to Perret, the foreman ordered him to make a lancet, an instrument whose design required the greatest care and the most extensive knowledge on handling steel. Since this task could not be entrusted to the untrained hand of an apprentice, the latter had to fail, and his dismissal from the workshop was assured. However, without uttering a word, he set to work and only left the workshop after having made the tool. The perfection of the instrument was so extraordinary, the turn of the lancet so new that the foreman, who was called Foucou, became his friend and his protector. The workshop workers also awarded him the instrument he had so advantageously perfected, as a reward. The manufacture of surgical instruments being the noblest part of the art of the cutler, he only thought of advancing knowledge and as it was essential for him to operate on a corpse himself, and to carry out almost all the surgeon's operations, in their presence, to achieve his goal, he attended the anatomy course of the School of Medicine. His attendance was noticed by a medical student Claude-Nicolas Le Cat, who was to become the famous surgeon. One day at the dissection workshop, Lecat was complaining about his scalpel, Perret came up to him to offer him one of his own making. Lecat, having admired the finish of the instrument, asked him who he was and what he was taking dissection lessons for. Perret having answered him that he was a cutler worker wishing to improve himself in the manufacture of surgical instruments, but that he was too poor to be able to devote himself to dissections, Le Cat replied: "You are poor. , you say, eh! well you will dissect with me." The plan of the cutler worker has long fuelled conversations at the School of Medicine in Paris. The Morand doctor, royal censor and inspector of military hospitals, have desired to know him, soon granted him protection. No major operation was undertaken without Perret being informed. Doctor Morand even allowed him to operate under his eyes. In 1753 he became a distinguished anatomist, aged 23, against all requests from Le Cat, who strongly urged him to be admitted to a surgeon, he asked to be received master at the provost of the cutlers of Paris. His reputation was such that he was received unanimously. He had even been dispensed, as a master's son, from the masterpiece, but he formally declared that he did not want to enjoy any dispensation and that he would perform a job to be submitted for the approval of the guard jurors. To do this, he presented his colleagues with a steel cup, which has been kept in the archives of the provost, as a model of its kind. He given the hallmark as a new master of the sign of a cup on May 24, 1753. His workshop, until the time of his death, was located in rue de la Tixéranderie and quickly became the busiest in the capital. The manufacture of surgical instruments was continuous; twenty workers could not meet all the demands. Perret nevertheless undertook to leave his name to posterity by reproducing the surgical instruments of the ancients. After eight years of work, he succeeded in recomposing the arsenal of surgical instruments from antiquity and modern times. In 1761 he gained the esteem and gratitude of the Royal Academy of Surgery by presenting for its approval the most complete collection that has existed of both ancient and modern surgical instruments. He was then designated to all operating physicians as the man who combined the superior qualities of the educated man with the skill of the maker. He carried out serious studies on all parts of the art of the cutler, improving the most common processes, descending to the most minute details when he believed his investigations would result in the relief of mankind. This is how he devoted the year to improvements to be introduced in the shape and manufacture of razors. To solve this problem, he was inspired by the carpenter's plane to adjust a wooden barrel to a razor blade. After many successful tests of the instrument, he turned to the editor at Mercure de France , Pierre-Antoine de La Place , who described it and advocated its advantages. Perret's razors have became fashionable in France and abroad. Patient in his research, Perret never engaged in the making of a surgical instrument, without seeking to know what were the improvements to which he was susceptible. If the author of the instrument was alive, he would get in touch with him, and share his discoveries with him. If the instrument had an old date, it delivered it to the public with modifications which always received the sanction of learned bodies. Perret was also interested in substances sprayed and prepared to polish and give shine to cutlery works, which cutlers call potées. After passing from emery to pewter pot to give the edge of lancets, which needed a more beautiful polish, a luster and shine more beautiful than emery, the English had made a red pot, which gives the steel a very beautiful black polish. Since its establishment, Perret has never ceased to make tests to find out the substances that went into so-called “England” red, which French cutlers used, but without knowing their composition. In 1769 he solved the problem, after infinite manipulations, by developing a composition which gave the steel a polish as lively and as beautiful as that of England, to which he gave the name of potée d 'steel. To prove the quality of his hotpot, he came up with the idea of ​​forging a steel mirror nearly 9 cm wide and 15.5 cm high, with an exquisite finish and perfect polish. Having submitted this piece, proving that its method in no way yielded to that of the English, to the Academy of Sciences, it charged the academicians Gabriel Jars andMathieu Tillet to report this discovery to him. After long investigations and a most serious examination during which he handed over a host of cutlery objects, the polish of which was more and more perfect, new tests were carried out before the commissioners themselves. same, a solemn report of the July 15, 1769, proclaimed that Perret's discovery deserved the approval of the Academy. Perret still had to perfect the steel pot, the process of which he had already published in the Gazette des arts et métiers . In 1780, in his Memoir on Steel, he gave his new recipe by declaring that his new hotpot was made without the intermediary of any acid and that it was free from all the defects of which the others were. fulfilled, that it was the best, the most expeditious, and very preferable to the red of England, which was nothing other than rock calcined in the furnace where one melts the iron mine. Far from keeping this invention to himself, he delivered it to his colleagues by a general circular, and the steel pot was put into practice, wherever cutlery had representatives. the September 24, 1769, he had the opportunity to present his mirror in polished steel to Louis XV , who made him cutler of the Château. Having already submitted several well-received dissertations to the Academy of Sciences and that of Surgery, he published, the January 15, 1770, The Pogonotomie or the art of learning to shave himself with how to know all kinds of clean stones to sharpen the tools or instruments, and how to prepare the hides for iron razors, how to 'to make some very good ones, followed by an important observation on bleeding. In 1770, Perret made a great improvement in the making of Doctor Charpentier's instrument , intended to pull out teeth. Perret removed anything that could interfere with the service of this instrument, whose mechanism was complicated and malfunctioned. He reduced its proportions and changed its shape and contours so much that it was visible that it was no longer the original instrument. Perret improved and perfected almost all surgical instruments, including scalpels, probes, algalia, lithotomes, instruments used for childbirth, and for the operation of the trephine. In 1761, the Academy of Sciences published several descriptions of certain arts and crafts. Fougeroux and Duhamel were responsible for publishing the section on cutlery. Having recognized the insufficiency of their knowledge to accomplish this meticulous and complicated work, they, in turn, asked Perret to take care of it. The description of the Art of the Cutler required endless work. To do this, he had the drawings made of more than 300 large plates, the meticulous details of which required no less than 3 large folio volumes. Having committed himself to the Academy to have the first part of his work published in the first days of the year 1770, he was exact in fulfilling his promise. The first part of the work relates to cutlery proper, while the second, published towards the end of 1772, deals with the manufacture of surgical instruments, including those intended for dissecting and embalming bodies, but also that of of the small profit of the factory of razor leathers. By publishing the three parts of the Art of the Cutter , Perret announced a Treaty of Metallurgy , which would include the record of his many experiments on the making and handling of steel. In 1773 he completed the third part of the description of Surgical Instruments by a Dictionary of the Art of the Cutler. In January 1774, he contracted a serious illness caused by overworking. To preserve his life, the most famous doctors of the capital prohibited him from using the forge or the anvil for more than a year. Faithful to this prescription, Perret took the opportunity to deal tirelessly with his Treaty of Metallurgy and on April 14, 1774, he submitted his dissertation entitled "On the breaks that hardening causes steel, and on the means of remedying it", to the Academy of Béziers.

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