Catholic Encyclopedia (1913)/De Jussieu
Name of five French botanists.
(1) ANTOINE DE JUSSIEU, physician and botanist, b. at Lyons, France, 6 July, 1686; d. at Paris, 22 April, 1758. He studied medicine at Montpellier, but as early as 1708 he was appointed, upon the recommendation of Fagon, to succeed the celebrated Tournefort as professor and demonstrator at the Jardin du Roi. By 1711 he was a member of the Academy of Sciences. After making botanical journeys over a large part of France, he explored in 1716 the flora of the Pyrenean peninsula. In addition to his activity as botanist he had a large medical practice, giving much attention to the poor. From 1718 he also made use in his practice of quassia bark (Cortex Simarubæ), the first of which had been sent in 1713 to the Jesuit Father Soleil at Paris from Cayenne. Antoine de Jussieu wrote an account of the bark in the "Mémoires" of the Academy for 1729, and Linnæus named after him the plant Simaruba Jussiæi. The "Mémoires" of the Academy for 1728, and Linnæus named after him the plant Simaruba Jussiæi. The "Mémoires" of the academy also contain papers by Jussieu on human anatomy, zoology, palæontology, and mineralogy. Haller ["Bibliotheca botanica", II (1772)] enumerates twenty botanical papers, of which the "Descriptio et icon Coffeæ (coffee)" of 1713 has historical value. In 1719 he published a new and revised edition, with an appendix, of Tournefort's "Institutiones rei herbariæ". He edited, further, the chief botanical work of the Dominican Jacques Barrelier (1606-73), a large and not unimportant treatise. Barrelier had left numerous drawings of plants and the text for a large work; the text was destroyed in a fire after Barreleir's death, but the drawings were saved. The work edited by de Jussieu contains 334 botanical plates, in folio, with 1392 figures, and is entitled "Plantæ per Galliam, Hispaniam et aliam observatæ" (Paris, 1714). He also left a work, "Traité des vertus des plantes" (Nancy, 1771).
(2) BERNARD DE JUSSIEU, brother of the above, b. at Lyons, 17 August, 1699; d. at Paris, 6 November, 1777; the date of death is sometimes given as 1776. He was educated at the large Jesuit college at Lyons until he had finished the study of rhetoric. In 1716 he accompanied his brother Antoine on the latter's journies to Spain, and developed into an enthusiastic botanist. He studied medicine at Montpellier, obtaining his degree in 1720, but practised medicine only for a short time. He was called to Paris by his brother Antoine, at the request of the botanist Vaillant, and after Vaillant's death in 1722 was appointed the latter's successor as professor and assistant demonstrator at the Jardin du Roi. He devoted all his energies to the royal garden, which his brother Antoine left almost entirely to him. He also made botanical excursions in the country surrounding Paris, and was able in 1725 to issue a revised and enlarged edition of Tournefort's work, "Histoire des plantes des environs de Paris"; this publication gained his admission into the Academy of Sciences. Many persons studied botany under his guidance, as the chemist Lavoisier. Owing to de Jussieu's unusual modesty and unselfishness he published very little, notwithstanding the wide range of his learning. He wrote an important paper on zoophytes, sea-organisms whose classification as plants or animals was then a matter of dispute. To study them he went three times to the coast of Normandy, proved in the "Mémoires" of 1742 that they belonged to the animal kingdom (before Peyssonel), and sought to classify them at this early date into genera. He also separated the whale from the fish and placed it among the mammals. The few botanical papers which he published (1739-42) treat of three water-plants.
In 1758 Louis XV made de Jussieu superintendent of the royal garden at Trianon near Paris, in which all plants cultivated in France were to be reared. His greatest achievement is the system according to which he arranged and catalogued the plants in the garden at Trianon; it is called "the older Jussieu natural system of plants of 1759", or the Trianon system. Jussieu himself never published anything about his system, nor did he offer any explanation of his arrangement, or give it a theoretical foundation. The genera are not arranged systematically in groups according to a single characteristic, but after consideration of all the characteristics, which, however, are not regarded as of equal value. De Jussieu proposed three main groups, to which he gave no name; these contained altogether fourteen classes, with sixty-five orders or families. Beginning with the cryptogams, the system proceeds from the monocotyledon to the dicotyledon, and closes with the coniferæ. Before this Linnæus had pointed out that only the natural system should be the aim of botanical classification, and published, outside of his artificial system, fragments of a natural system as early as 1738. Compared to the present development of the natural system, both Linnæus and de Jussieu offer scarcely more than a weak attempt at a natural classification of plants, but their attempt is the first upon which the further development rests.
De Jussieu was a thoughtful observer of nature, who behind things saw the laws and the Mind which gave the laws. Notwithstanding the great range of his knowledge he was exceedingly modest and unselfish. He was always animated by an intense love of truth, and his influence in the Academy and over French scholars was very great. He was besides deeply religious, preserving his religious principles and acting upon them to the end of his life. An old biography says of him: "No one has proved better than he how religious feeling can be combined with many sciences and true knowledge." He was a member of numerous academies and learned societies, e.g. the academies of Berlin, St. Petersburg, Upsala, London, and Bologna. In 1737 Linnæus named after him the genus Jussieua, which belongs to the family of the Onograceæ, and at the present day includes some thirty-six tropical species, chiefly South American.
(3) JOSEPH DE JUSSIEU, explorer and traveller, brother of the two mentioned above, b. at Lyons, 3 September, 1704; d. at Paris, 11 April, 1779. Highly educated in many directions and able to act as physician, botanist, engineer, and mathematician, he became a member of the scientific expedition sent by the Academy to Peru in 1735 to measure an arc of the meridian. After the task of the expedition was completed he remained in South America, supporting himself chiefly by the practice of medicine. His extended and arduous explorations in Peru took place mainly in the years 1747-50. The botanical results of these journeys were large, but the greater part of his manuscripts and collections was lost, and he finally returned to Paris in 1771, broken in health and with a clouded mind. He sent the seed of the heliotropium peruvianum to his brother Bernard, so that the introduction of this ornamental plant into Europe is due to him. He also undertook an investigation as to the area over which the cinchona tree flourishes and as to the first use of its bark by the Jesuits in South America.
(4) ANTOINE-LAURENT DE JUSSIEU (botanical abbreviation, Juss.), nephew of the above mentioned three brothers, b. at Lyons, 12 April, 1748; d. at Paris, 17 September, 1836. In 1765 he went to his uncle Bernard at Paris, where he first studied medicine. However, after he was appointed in 1770 professor and demonstrator at the Jardin du Roi in place of Lemonnier, he applied himself entirely to botany. In 1804 he was made professor of botany in the medical faculty at Paris, where he lectured until 1826. His memoir on the classification of the family of Ranunculaceæ (1773) led to his election to the Academy of Sciences. He adopted his uncle Bernard's ideas concerning the natural system, expanded them, gave them a theoretical basis, and applied them practically to the different families. All our knowledge concerning the natural system of his uncle we owe to him; consequently it is not possible to make a clear distinction between the work of the two men. As early as 1774, during the lifetime of the uncle, appeared the treatise "Exposition d'un nouvel Ordre des Plantes, adopté dans les démonstrations du Jardin royal", in the "Mém. de l'Acad. des Science" (1774), 175-97. His chief work, the result of many years study on the same subject, was entitled "Genera plantarum secundum ordines naturales disposita, juxta methodum in horto Regio Parisiensi exaratum anno 1774" (Paris, 1789). His work has remained the basis of all advance in the natural system of plant classification. It greatly influenced investigators in France, especially Cuvier and de Candolle. At a later date it also affected the German and English investigators, who had been at first suspicious of it as a product of the French Revolution (from 1789) and were extreme adherents of the Linnæan system. Even more vigorously than his uncle Bernard he upholds the theory of subordination or unequal value of the characteristics of plants, according to which certain characteristic signs have a more general and comprehensive importance than others. The characteristics are "weighed, not simply mechanically counted" (pesés et non comptés). Once ascertained, these essential characteristics are to be used like the chief fossils in geology, in order to assign plants to a definite group. It is true that in the application this principle frequently leads to false results. Antoine-Laurent gave to the three main groups of the original classification of his uncle the names of Acotyledon, Monocotyledon, and Dicotyledon, and divided them into fifteen classes, containing in all one hundred families. A most important fact is that he sought out and clearly defined the characteristics of families, largely indeed in later treatises. In the period, beginning in 1789, of the French Revolution, it may be said in brief that with other scholars he reorganized the Natural History Museum at Paris in 1790, and in 1808 was appointed by Napoleon counsellor of the university. During the years 1789-1802 he published no botanical works. It was not until the "Annales" and "Mémoires" of the Natural History Museum were founded that there began for him a new era of intense activity in investigation. He wrote for these publications, 1802-20, a very large number of memoirs and notes on individual species or genera, and especially monographs on numerous families. He was led largely to these labours by the work "De fructibus et seminibus plantarum" (1788-91) of the German botanist Joseph Gärtner (1732-91). Antoine-Laurent also published "Principes de la methode naturelle des végétaux" (Paris, 1824). He partly prepared a greatly desired second edition of the "Genera plantarum", but the work was never issued. Only what had been left ready for print, an entirely rewritten "Introductio" for the second edition, was published after his death by his son Adrien [An. des Sc. nat. (1837)].
(5) ADRIEN-HENRI DE JUSSIEU (botanical abbreviation, Adr. Juss.), son of Antoine-Laurent, b. at Paris, 23 December, 1797, d. there, 29 June, 1853. He received in 1824 the degree of Doctor of Medicine at Paris, presenting a treatise on the plant family Euphorbiaceæ. When his father retired in 1826 he was made professor of agricultural botany at the Jardin des Plantes; in 1845 he was made professor of organography of plants at the university. His textbook, "Cours élémentaire de botanique" (Paris), passed through numerous editions and translations. Besides a "Géographie botanique" (Paris, 1845), he also published monographs on several families of plants, especially the Malpighiaceæ (1843). He was president of the French Academy of Sciences.
SACHS, Geschichte der Botanik (Munich, 1875); RÁDL, Geschichte der biologischen Theorien, II (Leipzig, 1909).