Biographical encyclopedia
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186 [284] LACAILLE
NEEDHAM [285] [267] to Lapland, where he helped deter mine the length of the meridian. This led in 1743 to his writing a book on the shape of a rotating body like the earth, acting under the influence of gravity and centrifugal force. He went far beyond Newton [231] in his analysis and pro duced what is virtually the last word on the subject. He also showed how the shape of the earth could be calculated experimentally by measuring the force of gravity at different points through the timing of pendulum swings. Clairaut was one of those who did much work on the motions of the moon (lunar theory), a popular pastime among eighteenth-century astronomers. He calculated the effects of the gravita tional pull of Venus on earth as com pared with the pull of the moon. Com bining this with some of the observations of Lacaille [284], he obtained in 1757 the first reasonable figure for the mass of Venus (% that of the earth) and a new figure for the mass of the moon (%7 that of the earth). The former estimate is now known to be somewhat too small, the latter too high, but both were the best obtained up to that time. For a while, his studies on celestial mechanics created a particular stir for they seemed to disprove Newton’s theories. On the advice of Buffon [277], he extended his observations and found Newton to be right after all. As the year approached during which —as Halley [238] had predicted a half century before—Halley’s comet would return, Clairaut with the assistance of Lalande [309] worked out the effect of the gravity of Jupiter and Saturn upon the comet. He found that the two giant planets would slow it to the point where it would not reach the point closest the sun in its orbit (perihelion) until April 13, 1759. It was spotted on Christmas Day 1758 and reached perihelion within a month of the predicted time. [284] LACAILLE, Nicolas Louis de (la-kah'yuh) French astronomer Born: Rumigny, Marne, May 15, 1713
Died: Paris, March 21, 1762 Lacaille, the son of a gendarme, in tended to enter the Roman Catholic priesthood, but, with the help of Cassini [209], his interests drifted toward astron omy and mathematics and the church lost out. He was commonly referred to by the title “abbé,” however. He attained professorial rank at Ma zarin College in 1739. The most important event of Lacaille’s life was directing an expedition to the Cape of Good Hope from 1750 to 1754. His purpose was to obtain an accurate figure for the moon’s parallax in combi nation with observations by Lalande [309] in Berlin. From his observations in South Africa he prepared a catalogue of nearly two thousand southern stars plus a star map which was much more extensive and ac curate than Halley’s [238]. He discov ered Alpha Centauri, our nearest stellar neighbor, to be a double star and he filled the southern heavens with constel lations named for astronomical instru ments. In 1757 he prepared 120 copies of a small but very accurate catalogue of 400 of the brightest stars, more accurate, in fact, than any work except that of Brad ley [258], which was then being issued. Despite his poverty Lacaille gave away copies of his chart to any who asked. In 1761 he made a new and more accurate estimate of the distance of the moon, using calculations that for the first time took into account the fact that the earth was not a perfect sphere. His unremitting labor at his star charts, singlehanded, is supposed to have shortened his life. [285] NEEDHAM, John Turberville English naturalist Born: London, September 10, 1713
Died: Brussels, Belgium, Decem ber 30, 1781 Needham was ordained a Roman Catholic priest in 1738, and to get an ed ucation for that purpose in those days, he had to leave England. He finally set tled in Brussels in 1768.
[286] DIDEROT
DIDEROT [286] His most notable contribution to sci ence was his experimentation in 1748, in collaboration with Buffon [277], on spontaneous generation. He boiled mut ton broth and sealed it in glass con tainers. When the containers were opened a few days later, there were numerous microorganisms present. These, he concluded, had arisen from nonliving matter. It was twenty years later that Spallanzani [302] showed that Needham simply hadn’t boiled his broth long enough and that some spores had survived the short boiling period. In 1768, he was elected to the Royal Society, the first Roman Catholic to ac quire the distinction. When he died, he was the director of the Academy of Sci ences at Brussels. [286] DIDEROT, Denis (dee-drohO French encyclopedist Born: Langres, Haute-Mame, Oc tober 5, 1713 Died: Paris, July 31, 1784 As a youngster Diderot, the son of a master cutler, was educated at a Jesuit school, but the education did not take in certain ways, although he received a master’s degree from the University of Paris in 1732. He might have been a doctor or a lawyer, but he preferred to make a precarious living by small writ ings of all sorts, fiction, essays, transla tions, anything and to teach himself sci ence, as well. He produced some valu able material, too. He wrote a pamphlet, for instance, that represented the first se rious study of deaf-mutes. He developed notions on religion, despite his training, that seemed heretical, even atheistic, and spent three months in jail in 1749 possi bly because in one of his essays he spec ulated on the possibility that evolution might take place through a form of natu ral selection. In this there was an in teresting anticipation of Charles Darwin [554] and the theory he was to propound a century later. Life really began for Diderot when he emerged from prison. A bookseller suggested to him that he translate an En glish encyclopedia into French. Diderot agreed and quickly decided to make it a different and better project, to commis sion the best scholars in France to write articles on every facet of the new learn ing of Newton [231] and his followers. The mathematician D’Alembert [289] became his colleague and the first vol ume was published in 1751. For twenty years thereafter, additional volumes, first of text, then of plates, were produced, the Encyclopedia being completed in 1772 in twenty-eight volumes. It was a superhuman labor, for the au thorities from the beginning frowned on a work that, while not openly subversive, was riddled with views that ran counter to the accepted theories of monarchic absolutism and religious orthodoxy. It was legally suppressed in 1759, when it was half done. Diderot continued working on it clan destinely. Many of his collaborators and commissioned writers, including D’Alem bert, quit, not wishing to risk imprison ment. Diderot continued virtually alone, performing prodigies of self-education and composition, ending by writing many major articles himself. In the end the bookseller who was publishing the volumes turned prudent and eliminated many passages he believed too risky to include. The work, when done, accomplished a great deal. It was the first of the great encyclopedias, and it brought all the scientific views of the Age of Reason into one place where the general public might reach them. The Encyclopedia may have made Di derot famous, but it did not make him rich. Over a period of twenty years it had earned him perhaps twelve dollars a week. Once it was completed he decided to sell his library, out of financial neces sity, in order to supply a dowry for his daughter. The empress of Russia, Cath erine II (the Great) intervened. She bought it for five thousand dollars, then asked him to keep it for her and serve as her librarian at an annual salary. He was even invited to St. Petersburg in 1773 for some months of philosophizing with the empress. (She was even more op pressive in her country than Louis XV
[287] GUETTARD
LIND [288] was in France, but she fancied herself a liberal, as long as that liberality was confined to high philosophy and never had to be put into practice.) Diderot died just five years too soon to see the beginning of the French Revolu tion. The Encyclopedia had done much to rouse the emotions that were to ex plode in violence in 1789 and thereafter, so perhaps the old French government had been right to fear the industrious scribbler. [287] GUETTARD, Jean Étienne (geh- tahrd') French geologist Born: Étampes, Seine-et-Oise, September 22, 1715 Died: Paris, January 6, 1786 Guettard studied medicine at the Uni versity of Paris and like other physicians of the day was keenly interested in natu ral history, botany in particular. He kept the natural history collections of the duke of Orléans. Guettard observed the rocks of central France and, although he had never seen a volcano, he had read enough descrip tions of eruptions and their results to de cide that the rocks he saw had been formed at high temperatures. He was not quite ready to suppose the existence of a volcanic past, but others, notably Des- marest [296], took this logical final step. [288] LIND, James Scottish physician Born: Edinburgh, October 4, 1716
Died: Gosport, Hampshire, En gland, July 13, 1794 Lind, the son of a merchant, began his medical career as surgeon’s mate in the British navy and was promoted to sur geon in 1747. He left the navy in 1748 and obtained a medical degree at the University of Edinburgh in that year. It was natural for him to become in terested in scurvy, a disease that at tacked men on long sea voyages. Great Britain, as a maritime nation and depen dent for its national security on the efficiency of its fleet, was most threat ened by this disease, which killed far more sailors than enemy action did. (Its most eminent victim, perhaps, was Be ring [250].) Lind believed scurvy to be caused— and curable—by diet, after reading of the disease in besieged towns and explor ing expeditions, wherever the diet was limited and monotonous, without fresh fruits and vegetables. In 1747, he treated scurvy-ridden sail ors with various foods and found that citrus fruits worked amazingly well in effecting relief. When he was placed in charge of the naval hospital at Haslar in 1758 he began attempts to get the navy to adopt citrus fruit as a dietary staple. Unfortunately, brass hats are notoriously conservative and progress was slow. Cap tain Cook [300] kept off scurvy by this means in his great expedition in the 1770s, losing only one man in three years, and still the navy hesitated. Lind became physician to King George III in 1783 and still could not carry his point. In 1795, British sailors mutinied against vile treatment of all sorts. The British suppressed the mutiny brutally, but they were engaged in a desperate war with the French revolutionaries and they could not afford to keep the sailors sullen and disaffected. They therefore in stituted reforms. One of the sailors’ de mands had been to make use of Lind’s findings, so the navy adopted the prac tice of feeding lime juice to the sailors. Scurvy was wiped out, and British sailors have been called “limeys” ever since. It was to be a century before the work of Eijkman [888] and others showed that Lind unknowingly was treating a vi tamin-deficiency disease by supplying vi tamins in the diet. Lind also strove for the establishment of hospital ships in tropic waters, for cleanliness and good ventilation in sick bays, and is generally considered the fa ther of naval hygiene. He also suggested that sea water be made a source of ship board fresh water, through distillation, a matter now of world importance.
[289] D’ALEMBERT BONNET
[289] D’ALEMBERT, Jean le Rond (dah-Iahn-bearO French mathematician Born: Paris, November 16, 1717 Died: Paris, October 29, 1783 D’Alembert was brought up by a gla zier and his wife, after having been found abandoned at the church of St. Jean-le-Rond, from which he derived his name. He was the illegitimate son of an aristocrat who did, however, contribute to his support. In later years, when his talents were clearly evident, his mother tried to claim him, but D’Alembert proudly refused her. “The glazier’s wife is my mother,” he said. He never mar ried and lived with his foster parents till he was forty-seven. He graduated from Mazarin College in 1735 and was admitted to the Academy of Sciences in 1741, becoming its perpet ual secretary in 1772. He worked on gravitational theory, particularly on the precession of the equinoxes, and spon sored both Lagrange [317] and Laplace [347], who completed the job. For a time, he aided in the preparation of the great Encyclopedia of Diderot [286], writing the introduction to it, yet despite the “anti-establishment” character of this work, he received a pension from Louis XV.
As was tme of many of the great minds of the time D’Alembert was in vited to Berlin by Frederick II and to St. Petersburg by Catherine II, but he re fused both invitations. Rather out of character for D’Alembert is the fact that he bitterly disputed with Clairaut [283], apparently driven by jealousy of the lat ter’s work on Halley’s comet. [290] CANTON, John English physicist
July 31, 1718 Died: London, March 22, 1772 Canton, the son of a weaver, had little formal schooling, since his father took him out of school to work at the family business. Canton persisted in studying at night and a minister in the neigh borhood, recognizing the young man’s talent, offered to take charge of him. With this help, Canton eventually learned enough to become a school master. He made a number of minor dis coveries in physics and chemistry. He prepared artificial magnets in 1749 and was elected to the Royal Society as a re sult. In 1762 he demonstrated the fact that water was slightly compressible. He invented a number of devices in connec tion with electricity. His most interesting observations were made between 1756 and 1759, when he noted that on certain days the compass needle was more irregular than usual and that on those same days the aurora borealis was sometimes very conspic uous. This was the first observation of what are now called magnetic storms and led to the discovery of electric charges in the sky far higher than the clouds, by such men as Appleton [1158], a century and a half later. [291] BONNET, Charles (boh-nayO Swiss naturalist Born: Geneva, March 13, 1720 Died: Genthod, near Geneva, May 20, 1793 Bonnet, born of a wealthy French family, was not a good student in his youth. It didn’t help him that he was afflicted with increasing deafness. A pri vate tutor was engaged and eventually he studied law and obtained his degree in 1743. His hobby was natural history, how ever, and in the pursuit of that hobby he spent his quiet life, during the course of which he never left Switzerland. His most interesting discovery was that the tiny insects called aphids could re produce parthenogenetically—the female eggs could develop without the fertilizing action of the sperm. He also studied the respiration of insects and found in 1742 they breathed through pores which he named “stigmata.” He noted the capacity of a very simple animal, the freshwater hydra, to regenerate lost parts. The re
[292] CRONSTEDT CRONSTEDT
suit was that at the age of twenty-three, when he received his law degree, he was also elected to the Royal Society. In the 1750s his eyes began failing him, and to concentrate on tiny life- forms came to be beyond his powers. He turned to speculation. The fact that aphids produced parthenogenetically made him feel that every creature al ready existed, preformed, in the egg, and somewhere within that creature was a smaller egg with another creature, pre formed, within it, and so on without end. Generation nested within generation. This made it seem that species were fixed and could not change and this, in turn, made it necessary to explain those fossils that resembled no living creatures. This explanation Bonnet found by pos tulating periodic catastrophes involving all the earth. The fossils were remnants of creatures that dwelt before a catas trophe. Bonnet believed that after each catastrophe all forms of life stepped a notch upward, and he predicted a future catastrophe after which apes would be men and men would be angels. The principle of catastrophism domi nated geological thinking for a genera tion after Bonnet’s death, thanks to its adoption by Cuvier [396]. It was Bonnet who first made use of the term “evolu tion."
[292] CRONSTEDT, Axel Fredrik (kroon'stet) Swedish mineralogist
December 23, 1722 Died: Stockholm, August 19, 1765
Cronstedt was the son of a high army officer and received a good education. As a youngster he grew interested in mining and mineralogy and studied under Brandt [260]. His career was interrupted by army service between 1741 and 1743 when Sweden was at war with Russia. Cronstedt’s researches paralleled those of his teacher. Brandt had discovered cobalt in an ore that resembled copper ore but was not copper ore. Well, there was a second type of ore that resembled copper ore without being copper ore, and this, too, received a name that testified to the belief of the miners that the false ore was bewitched. It was called Kupfemickel (“Old Nick’s cop per,” in reference to the devil). On the other hand, this false copper ore was not a cobalt ore either and did not impart a blue color to glass as cobalt ore did. In 1751 Cronstedt tackled this ore and obtained green crystals that, when heated with charcoal, yielded a white metal that certainly was not copper. It resembled iron and cobalt, though it was different from both. Cronstedt discovered that, like iron but much less strongly, the new metal was attracted by a magnet—the first time anything but iron had been found subject to magnetic attraction since the days of Thales [3] twenty-three centuries before. In 1754 Cronstedt gave the new metal a shortened form of the old miners’ name and called it nickel. There fol lowed twenty years of controversy as to whether nickel was really a new metal or just a complex mixture of old ones, but Cronstedt’s view won out, though he did not live to see it. Cronstedt was one of those who re formed mineralogy and initiated a classification of minerals not only ac cording to their appearance, but also ac cording to their chemical structure. A book detailing this new form of classification was published in 1758. Cronstedt introduced the blowpipe into the study of minerals. By directing a thin jet of air into a flame, it increased the heat of the flame. When this hot flame impinged on minerals, much infor mation could be learned from the color of the flame, the vapors formed, the color and nature of the oxides or metal lic substances formed out of the mineral, and so oa He thus systematized and sharpened the technique of observing color changes as a means of chemical analysis—a technique which had been foreshadowed a century earlier by Glauber [190], For a century the blowpipe remained the most useful instrument in the armory of the chemical analyst, but its use called Download 17.33 Mb. Do'stlaringiz bilan baham: 
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