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Antoine-Laurent de Jussieu

1748-1836

French Physician and Botanist

Antoine-Laurent de Jussieu was an important influential botanist in France at the time of the French Revolution. He developed the principles that served as the basis for a system of classifying plants for over two centuries (in fact, it was only in 1999 that a major revision to this system was proposed), and he helped to completely reorganize the Natural History Museum during his tenure there.

Jussieu was born into a family of botanists. Three of his uncles, Antoine, Bernard, and Joseph, were respected botanists in pre-Revolutionary France, and his son, Adrien-Henri, followed the family tradition in the first half of the nineteenth century. At the age of 17, he traveled to Paris to live with his uncle Bernard while studying medicine. However, he was appointed a professor and demonstrator at the Jardins du Roi (the Royal Gardens) in 1770 and, thereafter, devoted himself to botany. He was named a botany professor at the University of Paris, remaining there until 1826, and he was elected to the French Academy of Sciences based on a paper he published when he was 25.

In fact, his Uncle Bernard had a significant impact on his own work, to the point that it is sometimes difficult to determine which man to credit for which discoveries. Part of this difficulty lies in the fact that some of his most important work was published before his uncle's death in 1777, and this is compounded by the fact that he was virtually the only person to transcribe and publish his uncle's work. However, it is likely that Antoine-Laurent's most important contribution to botany, his classification scheme for plants, was entirely his work, although it followed from some of the work done by Bernard before his death.

In a nutshell, Antoine-Laurent developed a system for classifying plants that proved much superior to the previous Linnaean system. The chief innovation lay in assigning unequal values to various traits or characteristics used to determine family affinities for plants. That is, when comparing leaf shape, stem branchings, flower petal arrangements, and other morphological characteristics of plants, not all of these were equally considered or weighted when determining which plants were more closely related. Using this scheme, he was able to group plants into three main categories, which were further divided into 15 classes and over 100 families. More importantly, his classification system made it possible to classify new plant species more quickly and accurately, an important advantage during this time of major exploration of the world with new plant specimens being returned from all corners of the globe.

Antoine-Laurent began his classification system by examining only a small number of plants, expanding it gradually during his tenure at the Jardins du Roi and the University of Paris. By the end of his life, it had been accepted by even British scientists (notoriously slow to accept new ideas from their political rivals, the French), and its use continues to this day. The system is not perfect, and mistakes have been made. However, it was not until 1999 that a serious challenge was posed, based on DNA evidence rather than on the physical characteristics of the plants. From this, we can infer that the system worked quite well, indeed, especially well, as it was developed during a time in which the mechanisms and process of heredity (i.e. genes and DNA) were not known.

Antoine-Laurent retired from his teaching duties in 1826, a decade before his death. He published widely during his working career and, even after retirement, continued working on a widely anticipated second edition of his most important book, Genera Plantarum. Unfortunately, he died after completing only a small part of this work, leaving his son, Adrien-Henri, to publish those portions he had completed after his death.

P. ANDREW KARAM


SMALLPOX INOCULATION BEFORE JENNER

Edward Jenner did not invent inoculation. In the 1770s he originated the idea of using cowpox (vaccinia) to inoculate against smallpox. In 1796 he performed his first vaccination, and in 1798 published the results of his 23 case studies. But long before Jenner, doctors were using smallpox itself to prevent smallpox.

The technique of using dried matter from smallpox lesions to inoculate uninfected individuals against smallpox was known in ancient China and precolonial Africa. In 1714 Emanuel Timonius reported the same sort of procedure practiced among the Greeks and Turks. In 1715 Giacomo Pilarino reported inoculating three children in Constantinople, Turkey, in 1701. About the same time, the prominent American Puritan preacher Cotton Mather owned a slave named Onesimus. In his native Africa, Onesimus had learned traditional inoculation. He taught it to Mather, who in turn taught it to his friend, Boston physician Zabdiel Boylston. Influenced not only by Mather but also by Timonius and Pilarino and supported by Benjamin Colman (1673-1747), Boylston began transplanting smallpox lesions into healthy patients in 1721. Of the 240 people he inoculated during the 1721 Boston smallpox epidemic, just 6 died.

Despite Boylston's success, popular superstition prevailed and inoculation became a public scandal in Massachusetts. An anti-inoculation mob bombed Mather's house in 1723. Yet even in the face of opposition from both medical and nonmedical groups, smallpox inoculation became a fairly common preventive medical procedure in England and America by the mid-eighteenth century. Among its supporters were William Douglass, Charles Maitland, Richard Mead, Thomas Dimsdale, Benjamin Franklin, and Benjamin Rush.

ERIC V.D. LUFT


Antoine-Laurent de Jussieu

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