Chaptal, Jean Antoine
Chaptal, Jean Antoine
(b. Nojaret, Lozère, France, 5 June 1756; d. Paris, France, 30 July 1832),
applied chemistry.
Chaptal’s parents, Antoine Chaptal and Françoise Brunel, were small landowners. It was, however, his uncle, Claude Chaptal, a wealthy and successful physician at Montpellier, who was to exercise the decisive influence on Chaptal’s education.
Chaptal was educated at the collèges of Mende and Rodez. In 1774 he enrolled in the Faculty of Medicine at Montpellier; on 5 November 1776 he submitted a thesis for the degree of bachelor of medicine and three months later was received as a doctor of medicine. He persuaded his uncle, who wanted him to go into general practice, to allow him to go to Paris to obtain wider experience. In Paris, Chaptal not only attended courses in medicine but also followed courses in chemistry given by Bucquet, Mitouard, and Sage. His enthusiasm for chemistry led to his appointment to a specially created chair at Montpellier (1780).
Some idea of Chaptal’s religious position may be obtained from a political tract published by him in 1790, Catechisme à l’usage des bons pairiotes, in which he inferred the brotherhood of man from the fatherhood of God. Later Chaptal showed his respect for the work of the church in France. As minister of the interior he effected the return of nuns to hospital work. In 1802 he presented a silver monstrance to the cathedral at Mende, and in 1827 he remembered the parish church where he had been baptized with another generous gift.
In 1781 Chaptal married Anne-Marie Lajrd, the daughter of a merchant dealing in cotton. Apart from a substantial dowry, Chaptal received 120,000 francs from his uncle. This gave him considerable independence and, equally important, it gave him capital to invest in the chemical industry that he was to found in the next few years. After a temporary setback at the time of the Revolution, Chaptal soon regained his former fortune. As Bonaparte’s minister of the interior he was a rich man; and when he left this post in 1804, he became a member of the Senate, again at a large salary. In 1802 Chaptal bought a magnificent château at Chanteloup in the Loire valley. He spent a considerable sum on the restoration of this property, and in 1808 he claimed that it was fit to receive a king. On the estate he raised sheep, distilled brandy, and experimented with the cultivation of sugar beets. Chaptal spent a considerable part of each year at his country house in the period 1804–1810 and again after Napoleon’s final exile in 1815. Later he was obliged to sell his property to pay the large debts incurred by his son in the chemical industry.
As evidence of Chaptal’s early interest in medicine we have his membership in the Société Royale de Médecine of Paris (3 October 1781) and one or two later medical memoirs. More important was his membership in the Société Royale des Sciences de Montpellier (from 24 April 1777), where he began to present a succession of memoirs. Most of this early work was of little value and was never published. In 1787, however, a memoir by Chaptal on fermentation was considered by the Montpellier society to be worthy of a prize of 300 livres. By then, though Chaptal was looking for national recognition, and his work began to appear in the Mémoires of the Paris Académie Royale des Sciences. Chaptal was elected a nonresident associate in the chemistry section of the First Class of the Institute on 28 February 1796. On his removal to Paris he was elected as a resident member to a vacancy in the chemistry section on 24 May 1798. He was president of the First Class in 1803–1804. As minister of the interior at this time Chaptal drew up a project for the reform of the Institute, by which the post of permanent secretary was reestablished and each class of the Institute was given greater autonomy. Chaptal was again elected president in 1825 of what was once more known as the Académie des Sciences. He joined the Société Philomatique in 1798 but was never a very active member. Chaptal was a close friend of Berthollet, whose house at Arcueil he often visited. It was probably only in 1810, however, that he joined the famous Society of Arcueil. There was only one society to which Chaptal devoted himself wholeheartedly. This was the Société d’Encouragement pour l’Industrie Nationale, of which he was president from its founding in 1801.
At the beginning of the Revolution, Chaptal showed himself to be a liberal in politics; but in 1793, when extremists gained the upper hand, he was imprisoned for a short time. In December 1799 a consulate was established in France. One of the consuls, Jean Cambacérès, was a close friend of Chaptal and appreciated his abilities, so Chaptal was appointed a councillor of state. On 6 November 1800 Chaptal was made acting minister of the interior, an appointment that was confirmed on 21 January 1801. For four crucial years in the reconstruction of post-revolutionary France Chaptal held the key post in the government. As minister of the interior he was responsible, through the system of prefects, for the general administration of the whole of France. In particular he was responsible for education, religion, public works, customs and excise, theaters, state factories, palaces and museums, hospitals, and prisons. Chaptal exercised patronage generally in the field of industry and commerce.
Chaptal’s administration was notable for its advocacy of an expansion of technical education. He had plans for the establishment of a school of dyeing at Lyons, a school for pottery at Sèvres, and a school at Montpellier concerned with distillation and the preparation of acids. He was not able to realize all these projects, but he did bring about the removal of the École des Mines from Paris to a mining locality in 1802 so that students should have a coordinated program of lectures and practical work, He was able to extend the Conservatoire des Arts et Métiers in Paris into an institution for technical education, including technical drawing, spinning, and weaving. It was Chaptal who was responsible for the first major exhibition of French industry, which was held in Paris in 1801. Even after he resigned from the post of minister of the interior (8 July 1804), Chaptal continued to be available to the French government for technical advice—for example, as a member of the Council for Commerce and Industry. In the final months of Napoleon’s rule Chaptal was given special powers to organize conscription. Napoleon’s confidence in Chaptal’s loyalty and ability was again shown during the Hundred Days, when he was appointed minister of agriculture, commerce, and industry. Under the Restoration, Chaptal at first withdrew completely from public life. On 7 December 1815 William Lee, as United States consul, wrote to the French chemist, inviting him to immigrate to the United States, where the government fully appreciated his talents. Chaptal declined this invitation, as he had an earlier one after the Revolution. In 1818 Chaptal was nominated to the Chambre des Pairs.
In 1780 Chaptal took up his appointment to the new chair of chemistry at Montpellier. In an inaugural lecture to the States of Languedoc, he pointed to the danger of science’s becoming a language intelligible only to a small circle of initiates. In the spirit of Diderot, he claimed the need for someone to act as a link between the academies and the people and to explain in simple language the value of science to society. There was a great potential application for chemistry in the south of France. The mines, salt deposits, large grape harvest, and other natural resources were waiting to be exploited. These ideas were repeated in his first book, Mémoires de chimie, which, dating from November 1781, was too early a work to constitute a significant contribution to chemistry. In this book he understandably showed his concern with the chemical industry—for example, in a memoir on a means of reducing the consumption of soda in glassworks—but there were also many contributions to pure chemistry.
Chaptal held two further teaching appointments. In 1795 he was professeur de chimie appliquée aux arts for a few months at the newly founded École Polytechnique, where he shared a course with Berthollet. He then returned to Montpellier to take up the post of professeur of chemistry at the reorganized medical school there.
Chaptal made few original contributions to pure chemistry, but he was one of the greatest chemical manufacturers of his age. He was always ready to apply the lessons of the chemistry laboratory to the factory. For example, he improved his process for the manufacture of sulfuric acid by applying Lavoisier’s new chemical theory based on oxygen. He distinguished three degrees of oxidation in the acid corresponding to sulfurous, sulfuric, and fuming sulfuric acids, respectively. Nevertheless, he compares unfavorably as a man of science with someone like his friend Berthollet. Whereas Berthollet was concerned with establishing general principles and applying them to particular cases. Chaptal wrote as an industrialist with great practical experience, whose concern with the fundamental understanding of nature was subordinate to his interest in controlling chemical reactions. Nevertheless, Chaptal’s voice was an important and influential one in advocating the introduction of science into the old craft procedures. On the practical importance of chemistry he wrote:
Chemistry bears the same relation to most of the arts, as the mathematics have to the several parts of the science which depend on their principles. It is possible, no doubt, that works of mechanism may be executed by one who is no mathematician; and so likewise it is possible to dye a beautiful scarlet without being a chemist; but the operations of the mechanic and of the dyer are not the less founded upon invariable principles, the knowledge of which would be of infinite utility to the artist.
We continually hear in manufactories of the caprices and uncertainty of operations; but il appears to me that this vague expression owes its birth to the ignorance of the workman with regard to the true principles of their art. For nature itself does not act with determination and discernment, but obeys invariable laws; and the inanimate substance which we make use of in our manufactures, exhibits necessary effects, in which the will has no part and consequently in which caprices cannot take place. Render yourselves better acquainted with the materials you work upon, we might say to the artists; study more intimately the principles of your art; and you will be able to foresee, to predict, and to calculate every effect….1
Chaptal was also an economist who showed a detailed concern for questions of cost, transport, use of chemicals, and the sources of labor to be used. He was also deeply concerned with agriculture, which he described as “the basis of public welfare.” He insisted on the utility of chemical knowledge in improving the yield of crops. As minister of the interior he tried by imports to raise the standard of French cattle and sheep. In the production of wine he proposed that in years in which there had been insufficient sun, and fermentation of the grape juice took place only with difficulty, an improvement could be made by adding sugar. This simple but effective method of improving the yield of wine became known as “chaptalization.” Chaptal showed that in fermentation it was not necessary to leave the vats open to the air, and by enclosing them he prevented the evaporation of the alcohol. He proposed improvements in the apparatus for distilling alcohol in which heat was retained and fuel consumption was drastically reduced.
The manufacture of acids was a particularly important part of Chaptal’s contribution to industry. He sold his first nitric acid and sulfuric acid in 1785, and in 1786 he added spirit of salt. By carefully dissolving hydrogen chloride in water he was able to produce hydrochloric acid successfully and comparatively cheaply, so that, according to Fourcroy, he was able to supply not only towns in France, including Lyons and Paris, but was able to export it to England and Germany.
In January 1786 Chaptal discovered that oil of vitriol could form hexahedral crystals, given suitable conditions of concentration and cold. This memoir was first presented to the Academy of Sciences at Montpellier, which considered it of sufficient merit to submit it to the Paris Academy for publication. In this way it became the first memoir of Chaptal’s to be published. In 1787 Chaptal reported on his efforts to manufacture acids of great purity at minimum cost. In 1788 he asked the States of Languedoc for a subsidy to cover further research on the production of alum and mineral acids.
Apart from the mineral acids, Chaptal manufactured large quantites of oxalic acid; sal ammoniac; blue, green, and white vitriol; white lead; and, especially, alum. Alum was a particularly important product, being used not only as a mordant in dyeing but also in tanning and in the preparation of paper and cloth. In 1784 Chaptal discovered a source of alum in Languedoc; and by suitable treatment with air and water, followed by calcination, extraction, and crystallization, he was able for the first time to produce alum in reasonable quantities on French soil. Manufacturers continued to prefer alum of Tolfa, imported from Italy, but Chaptal and others were later able to show by chemical analysis that alum produced in France need not be inferior.
Although Lavoisier had suggested in 1780 that alum was not a simple double salt, this possibility was overlooked. Chaptal, for example, writing in 1790, considered alum as the sulfate of alumina but said that alkali had to be added to neutralize the excess of acid which would otherwise prevent the formation of crystals. Berthollet, in his Elemens de l’art de la teinture (1791), reported the opinion of François Descroizilles that the sulfate of potash and the sulfate of alumina enter into the composition of alum in some way. It was left, however, to Vauquelin and Chaptal independently in 1797 to conclude that alum was a triple salt. In his textbook of 1790 Chaptal was concerned with the composition of several salts. He corectly stated that fuming liquor of Libavius (stannic chloride) is a “muriate” in which the acid is in the state of “oxymuriatic acid.” He was concerned with the impurity of many salts sold in France, notably Epsom salts and antimony compounds. Because of the dangers involved in the medicinal use of the latter he advocated governmental inspection.
Although Chaptal was not in Paris at the time that Lavoisier collaborated with Guyton de Morveau, Berthollet, and Fourcroy in the reform of chemical nomenclature (1787), he was able to suggest a simple improvement in the new nomenclature by the logical substitution of nitrogène (1790) for the azote of the Paris chemists. About this time Chaptal became conviced of the superirity of the new oxygen theory, and in 1791 Lavoisier wrote to him to express his satisfaction at having won him over from the old phlogiston theory. Chaptal was happy to testify to the improvement the oxygen theory made not only in theoretical chemistry but also in the practical chemistry of which he was such an influential exponent: “It is this doctrine alone which has led me to simplify most of the processes, to bring some of them to perfection, and to rectify all my ideas.”2
Chaptal made few contributions to animal chemistry, although it should be remembered that he had first embarked upon a study of chemistry through medicine. Because of his medical qualifications it is all the more interesting to examine his ideas on vitalism, a subject to which he devotecd several pages in one of his technical works. He summed up his views as follows:
Chemistry in its application to living bodies may therefore be considered as a science which furnishes new means of observation, and permits us to verify the resuls of vitality by the analysis of its products. But let us beware of intermeddling in the peculiar province of vitality. Chemical affinity is there blended with the vital laws which defy the power of art.3
Chaptal carried out work on the extraction of saltpeter, being one of many French chemists called upon in 1793–1794 to apply their knowledge to national defense. In the southwest of France he organized the extraction of saltpeter from suitable natural sources of decaying organic matter. He also insisted on the construction of artificial niter beds to safeguard future supplies. Equally useful to the national economy was Chaptal’s work on bleaching. The use of “oxymuriatic acid” (chlorine) to bleach cotton had been discovered by Berthollet. In a memoir published in 1787 Chaptal extended this process to the treatment of paper. He proposed the use of chlorine for treating old paper and rags so that they could be used in the manufacture of white writing paper previously made exclusively from unprinted linen. He suggested that chlorine could also be used in the restoration of faded books and prints and in the removal of ink stains. Chaptal later favored the use of chlorine as a disinfectant—for instance, in prisons—and suggested that it was superior to the hydrogen chloride favored by his colleague Guyton de Morveau. He also introduced the method of bleaching by soaking the material in alkali and then treating it with steam.
Chlorine was prepared from hydrochloric acid, of which Chaptal was a major manufacturer. After his resignation as minister of the interior in 1804 he was again able to take a close interest in his chemical factories. The one at Ternes, near Paris, of which he made Darcet manager, produced oxalic acid, tartaric acid, corrosive sublimate, potassium and sodium arsenates, copper sulfate, tin and lead salts, alcohol, ether, and ammonia. Soda was refined there and sulfuric acid was concentrated in platinum vessels. According to Pigeire, under the Empire he had at his factory at La Folie, near Nanterre, 150 workmen engaged in the annual production of about 600 tons of hydrochloric acid, 400 tons of sulfuric acid, sixty tons of nitric acid, 1,200 tons of crude soda, 400 tons of potassium carbonate, sixty tons of potassium sulfate, and 600 tons of alum. Chaptal’s third factory was near Martigues, on the Mediterranean coast of France, and here soda was one of the main products.
Chaptal, a constant advocate of France’s self-sufficiency, was an early enthusiast of the possibility of replacing cane sugar with beet sugar. In 1811 he was a member of a committee appointed by the First Class of the Institute to examine the possible production of beet sugar. It was not until 1815, when the end of the war permitted the resumption of trade with the West Indies and threatened the ruin of the sugar beet industry, that Chaptal presented a memoir on the subject to the Institute. He was anxius to show that the industry, if efficiently run, could justify itself economically. It was largely due to his efforts, with the later support of Thenard, that this industry continued to function in France.
In his book Chimie appliquée aux arts (1807), Chaptal warned the industrialist of the danger, on the one hand, of ignoring the potential help of science. On the other hand, Chaptal warned him not to found a new factory just on the basis of a laboratory experiment—suitable large-scale trials were necessary. The chemist could be no more than a consultant. It was the manufacturer who knew the market and who must decide to what extent and in what way science was to be applied. A manufacturer who found his good undercut by a competitor should not ask for government regulations to protect himself. Nor should the manufacturer be protected by tariffs on imported goods, “for the manufactuer does not strive to improve, unless he has before him articles of a better or more economical manufacture than his own.” Chaptal also discussed the location of industry and the supply of labor.
NOTES
1. Elements of Chemistry, W. Nicholson, trans., 2nd ed. (London, 1795), 1, Xliii.
3. Chemistry Applied to Arts and Manufactures, W. Nicholson, trans. (London, 1807), 1, 50.
BIBLIOGRAPHY
I. Original Works. Chaptal’s articles include “Observations sur la crystallisation de l’huile de virtriol,” in Mémoires de l’Académie royale des sciences (Paris) (1784), 622–630; “Observations sur l’acide muriatique oxigéné,” ibid. (1787), 611–616; “Obsevations sur la manière de former l’alun par la combinaison directe de ses principes constituans,” ibid. (1788), 768–77; “Sur les moyens de fabriquer de la bonne poterie a Montpellier, et sur un vernis qu’on pent employer pour les enduire,” in Annales de chimie, 2 (1789), 73–85; “Sur quelques phénomènes que nous presente la combustion du soufre,” ibid., 86–91; “Sur le caves et le fromage de Roquefort,” ibid., 4 (1790), 31–61; “Instruction sur un nouveau procédé pour le raffinage du salpetre,” in Journal de physique, 45 (1794), 146–152, written with Champy and Bonjour; “Observations sur le savon de laine et sur ses usages dans les arts,” in Mémoires de l’Institut, 1 (1796), 93–101; “Analyse comparée des quatre principales sortes d’alun connues dans le commerce; et observations sur leur nature et leur usage,” in Journal des mines, 5 (1796), 93–101; “Analyse comparee des quatre principales sortes d’alun connues dans le commerce; et observations sur leur nature et leur usage,” in Journal des mines, 5 (1796–1797), 445–456; “Sur la production artificielle du froid,” in Annales de chime, 22 (1797), 280–296; “Vues generales sur la formation du salpêtre,” ibid., 20 (1797), 308–355; “Considérations chimiques sur l’effet des mordans dans la teinture en rouge du coton,” ibid., 26 (1798), 251–258; “Considérations chimiques sur l’usage des oxides de fer dans la teinture du coton,” ibid., 266–277; “Sur la necessite et les moyens de cultiver la barille en France,” ibid., 178–187; “Observations chimiques sur la couleur jaune qu’on extrait des végétaux,” in Mémories de l’Institut, 2 (1798), 507–516; “Sur la manière dont on fertilise les montagnes dans les Cevennes,” in Annales de chimie, 31 (1799), 41–47; “Essai sur le perfectionnement des arts chimiques en France,” in Journal de physique, 50 (1800), 217–233; “Mémoire sur le vin,” ibid., 51 (1800), 133–149; “Notice sur une nouvelle méthode de blanchir le coton,” ibid., 305–309; “Rapport des expériences sur le sucre contenu dans la betterave,” ibid., 371–389; “Sur les vins,” in Annual de chimie, 35 (1800), 240–299; 36 (1800), 3–50, 113–142, 225–258; 37 (1800), 3–37; “Notice sur un nouveau moyen se blanchir le lings dans nos ménages,” ibid., 38 (1801), 291–296; “Vues générales sur l’action des terres sans la végétation,” in Mémoires de la Société d’agriculture de la Seine, 4 (1802), 5–14; “Rapport sur la question de savoir si les manufactures qui exhalent une odeur désagréable peuvent etre nuidibles à la santé!,” in Annales de chimie, 54 (1805), 86–103, written with Guyton de Morveau; “Rapport sur deux mémories de M. Gratien Lepère, relatifs aux pouzzolanes naturelles et artificielles,” ibid., 64 (1807), 273–285; “Notice sur quelques couleurs trouvées à Pompeïa,” in Mémories de l’Institut (1808), 229–235; “Observations sur le distillation des vins,” ibid., 170–194; “Mémorie sur le sucre de betterave,” in Annales de chimie, 95 (1815), 233–293; n.s. 7 (1817), 191–193; and “Recherches sur la peinture encaustique des anciens,” ibid., 93 (1815), 298–313.
Chaptal’s books are Mémoires de chimie (Montpellier, 1781); Éléments de chimie, 3 vols. (Montpellier, 1790; Paris, 1794, 1796, 1803), also trans. into English by W. Nicholson as Elements of Chemistry, 3 vols. (London, 1791, 1795, 1800, 1803; Philadelphia, 1796; Boston, 1806); L’art de faire, gouverner et perfectionner le vin (Paris, 1801; repr. 1807, 1811; 2nd ed., 1819; 3rd ed., 1839), also trans into Italian (18120–1813); Art de la teinture du coton en rougr (Paris, 1807); Chimie appliquée aux arts, 4 vols. (Paris, 1807; 2nd ed., Brussels, 1830), trans, as Chemistry Applied to Arts and Manufactures, 4 vols. (London, 1807) and as Die chemie in hier Anwendung auf Kiinste, 2 vols. (Berlin, 1808); Principes chimiques sur l’art du teinturier-dégraisseur (Paris, 1808); De l’industrie française, 2 vols. (Paris, 1819); and Chimie appliquée à l’agriculture, 2 vols. (Paris, 1823, 1829), trans. by W.P. Page as Chymistry Applied to Agriculture (Boston, 1835, 1838; New York, 1840).
II. Secondary Litrature. On Chaptal of his work see J.A. Chaptal, La vie et l’oeuvre de Chaptal. Mémoires personnels rédigés par lui-même de 1756 à 1804. Continués, d’après ses notes, par son arrière-petit-fils jusqu’en 1832 (Paris, 1893); M.P. Crosland, The Society of Arcueil. A View of French Science at the Time of Napoleon I (Cambridge, Mass., 1967), passim; P. Flourens, “Éloge historique de Jean Autoine Chaptal” (read at public meeting of 28 Dec. 1835), in Mémoires de l’Académie des sciences de l’Institut, 15 (1838), 1–39; J. M. de Gerando, “Notice sur Chaptal” (read at general meeting of the Société d’encouragement, 22 Aug. 1832); J. Pigeire La vie et l’oeuvre de Chaptal (1756–1832) (Paris, 1932); and R. Tresse, “J. A. Chaptal et l’enseignement technique de 1800 à 1819,” in Revue d’histoire des sciences, 10 (1957), 167–174.
M. P. Crosland