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291 [430] BRACONNOT STEPHENSON
the heart through the insulating breast tissue by direct application of the ear. So he rolled up a paper notebook into a cyl inder, placed one end to the chest and the other to his ear. He was pleased to find that the heart sounds were actually louder. He constructed further cylinders out of wood and, in short, invented what he named the stethoscope (“to view the chest”), the instrument the general pub lic most closely associates with the medi cal profession. He is supposed to have got the idea of the stethoscope by watch ing children listening to one end of a long stick that was being tapped at the other end. In 1819 he published the details of his discovery and described his methods of diagnosis by listening to sounds (“aus cultation”). Laénnec fought against the then prevalent medical practice of bleed ing (usually by the application of leeches). This was so common that “leech” came to mean physician. The pernicious practice killed many in its time (including George Washington in 1799) and as the mid-nineteenth century approached, it faded. Laennec was appointed to a profes sorial post at the College de France in 1822. He did not die at so young an age as Bichat [400] but his death of tubercu losis (probably contracted from his pa tients) at forty-five may fairly be said to be too soon. [430] BRACONNOT, Henri (bra-kuh- noh')
French naturalist Born: Commercy, Meuse, May 29, 1781
Died: Nancy, January 13, 1855 Braconnot was the son of a lawyer who died when Henri was seven. The boy did not enjoy the school he was placed in, nor did he like his stepfather. At fourteen he was apprenticed to an apothecary and eventually he gained enough prominence as a self-taught natu ralist to be recommended by Fourcroy [366] for the position of director of the Botanic Garden in Nancy. He was ap
pointed to the job and with that, things improved for him. He grew interested in the chemical constitution of plants. In 1819 he boiled various plant products such as sawdust, linen, and bark with acid and from the process obtained glucose, a simple sugar. This had previously been obtained by the boiling of starch with acid. It was easy to decide that the molecule of starch was built up out of glucose units and that in many plants there must be some nonstarch material that was also built up out of glucose units, presumably in different fashion. It was the nonstarch material that Braconnot was breaking down. Some fifteen years later, this was isolated and studied by Payen [490], who named it cellulose. Braconnot never married and, after the death of his stepfather, lived with his mother till she died in 1843. He was painfully shy and, mistrusting doctors (not without reason in those days), suffered agonies from untreated stomach cancer—which carried him off eventu ally.
[431] STEPHENSON, George English inventor Born: Wylam, Northumberland, June 9, 1781 Died: near Chesterfield, Derbyshire, August 12, 1848 Born in humble circumstances Ste phenson nevertheless had the advantage of a father who was fireman for a steam engine that was used to pump water at a coal mine. At the age of fourteen he was helping his father and by seventeen he was going it alone. This exposed him to mechanical contrivances and he was fascinated. However, he so completely lacked an education that he had to at tend a night school in his late teens to learn to read in order to study the work of Watt [316] and to read the news re ports of the Napoleonic Wars. Then, he was called up to the army but he hired a substitute to report for him. This was legal at that time but it consumed his savings and kept him from emigrating to [431] STEPHENSON BREWSTER
the United States as, after the death of his wife and daughter in 1805, he had been planning to do. But he had a son, whom he sent to school. As the son stud ied, Stephenson did the homework along with the young man so that he, too, could get at least the beginnings of an education. By 1815 he had learned to manufac ture engines and was ingenious enough to devise a miner’s safety lamp at about the same time that Davy [421] was devis ing his. Stephenson received £1,000 for this feat. Stephenson put his ingenuity to work to devise a traveling steam engine, one that could turn wheels that would carry itself and cargo overland, as Fulton [385] had demonstrated could be done on the water. In this he was not first in the field, for others, notably Trevithick [399], had preceded him, as Fitch [330] had preceded Fulton. It was Stephenson, however, whose devices caught on and became profitable and so it is he who is usually considered the inventor of the steam locomotive (“self-moving”). Ste phenson was the first to make use of flanged wheels. On September 27, 1825, one of his lo comotives pulled passenger cars along rails, the first practical passenger railway ever built. Thirty-eight cars were drawn at speeds of twelve to sixteen miles an hour; and for the first time in the history of the world, land transportation at a rate faster than that of a galloping horse became possible. By 1830 a railway using eight engines built by Stephenson and his co-workers was opened between Liverpool and Man chester. This was the beginning of a vast flowering of railways that put horse- drawn coaches out of business, restricted the use of canals, and opened the inte riors of continents, making land areas as traversible in all directions as the sea it self. Stephenson, having retired in 1840, lived to see the beginning of this revolu tion in transportation. However, a less spectacular advance in land trans portation, pioneered by McAdam [369] and seemingly defeated at the time, was to come into its own a century later. [432] POISSON, Simeon Denis, (pwah- sohn')
French mathematician Born: Pithiviers, Loiret, June 21, 1781 Died: Paris, April 25, 1840 Poisson, the son of a retired soldier, was marked for the medical profession by his father, but had very little aptitude for it, and he turned to mathematics in stead, qualifying for the École Poly technique in 1798. There he studied under Laplace [347] and Lagrange [317] and impressed both of them with his ability. On his graduation in 1800, he was in stantly offered a teaching position there, thanks to the strong backing of Laplace and by 1806 had replaced Fourier [393] in an important professorial position. Poisson labored to refine the earlier work of Laplace and Lagrange in celes tial mechanics, and the work of Fourier on heat. He also applied mathematics to the study of electricity and magnetism. He is best known for his work on probability and on something called Poisson’s distribution, which deals with events that are in themselves improbable but that take place because of the large number of chances for them to occur (like automobile deaths, for instance.) This is now central to any serious con sideration of such events. Like Laplace, Poisson adjusted himself without difficulty to political changes, and in 1837 was made a baron by Louis Philippe. [433] BREWSTER, Sir David Scottish physicist
December 11, 1781 Died: Allerly, Roxburghshire, February 10, 1868 Brewster, the son of a schoolmaster, was educated for the ministry but hated to preach and in his twenties gave up the calling for science and became editor of the Edinburgh Encyclopaedia. In 1815 he found that a beam of light could be split into a reflected portion
[434] BIELA
GUTHRIE [435] and a refracted portion, at right angles to each other, and that both would then be completely polarized. This is still called Brewster’s law and earned him the Rumford medal in 1819. The law can be neatly explained by supposing light to consist of transverse waves. Neither the longitudinal wave theory nor the particle theory could explain it. Nevertheless, Brewster remained an ardent adherent to the particle theory all his life, refusing to accept the ether. This seemed at the time to be an example of scientific ultraconservatism, but a half century after his death he was to be vin dicated by Einstein [1064]. Brewster, by the way, invented the ka leidoscope in 1816, a scientific toy that has never ceased to amuse the young— and the old. He patented it and although thousands were sold in a few days, it was so easy to pirate, he earned virtually nothing from it. He also invented the stereoscope, through which one views two slightly different pictures, one with each eye, giving the illusion of three- dimensionality. Brewster wrote a biography of Newton [231] and helped found the British Asso ciation for the Advancement of Science in 1831. He was knighted in 1832. At the age of 75, he married a second time and had a daughter some years later. [434] BIELA, Wilhem von (bee'luh) Austrian astronomer Born: Rossla, March 19, 1782 Died: Venice, Italy (but then under Austria), February 18, 1856 Biela, bom into the Bohemian aristoc racy, served as an officer in the Austrian army. He achieved a captain’s rank and was wounded at the battle of Leipzig in 1813, fighting against Napoleon. He re tired from the army in 1846 with the rank of major. While in the army, Biela studied as tronomy and eventually amused himself by becoming a comet-hunter. This is a useful task for an amateur since profes sional astronomers, by and large, had other things to do. As a comet-hunter Biela gained unex pected fame, for in 1826 he observed “Biela’s comet,” which had been ob served before. His own name became at tached, however, because he worked out its orbit, which had not been done before and which turned out to be a short one. The comet had a period of less than seven years, which made it the second short-period comet to have been discov ered, the first having been pinned down the previous decade by Encke [475], Biela then passes from scientific his tory, leaving his name, as did the con temporary English amateur astronomer Baily [406], firmly fixed to an astro nomic phenomenon, without doing much more of note. However, Biela’s comet did something more. It turned out to be mortal, something Kepler [169] had sus pected of comets generally three cen turies earlier, and it is that which gave Biela’s name its immortality. In 1846 Biela’s comet split in two. When it showed up next time round in 1852, the two parts were widely sepa rated. Before its next scheduled return, Biela himself died, which was perhaps just as well in one respect, for Biela’s comet never returned. It was the first time a member of the solar system had died before the eyes of watching astrono mers.
When Biela’s comet should appear, a crowd of meteors often appears instead. These, first observed in 1872, are called the Bielids and they offered the first con crete evidence of a close connection be tween comets and meteors. [435] GUTHRIE, Samuel American chemist and physician Born: Brimfield, Massachusetts, 1782
Died: Sackets Harbor, New York, October 19, 1848 Guthrie obtained his medical degree from the University of Pennsylvania and began practice in Sherburne, New York. He was one of the pioneers in the intro duction of Jenner’s [348] vaccination procedure into the United States. He served as surgeon in the army dur ing the War of 1812. One of his warlike 2 9 4
[436] STURGEON
MAGENDIE [438] inventions was percussion powder, which would explode on impact and without use of a flame. More important he discovered chloro form in 1831. This compound was shortly to come into prominence in con nection with anesthesia, one of the few advances in nineteenth-century science (as opposed to technology) that can be associated mainly with the United States. [436] STURGEON, William English physicist
May 22, 1783 Died: Prestwich, Lancashire, De cember 4, 1850 Sturgeon was a shoemaker’s apprentice in early life. He was educated in the army with the help of his officers, who apparently recognized his ability. Sturgeon grew interested in electricity while observing a severe thunderstorm in Newfoundland, and after he returned to civilian life in 1820 he put Ampère’s [407] notion of a solenoid into practice (in about 1823). His own addition, per haps accidental to begin with, was to wrap the wire about an iron core, mak ing eighteen turns or so. The wires them selves, when a current was running through them, became magnetic. Each coil reinforced all the rest, since they formed a set of parallel wires with the current running in the same direction through all. The magnetic force seemed to be concentrated in the iron core. Stur geon varnished the core to insulate it and keep it from short-circuiting the wires, and used one that was bent in the shape of a horseshoe. His device could lift nine pounds— twenty times its own weight—while the current was running. When the current was turned off the magnetic properties ceased. Sturgeon had invented the first electromagnet, a device soon to be greatly improved by Henry [503]. In later life Sturgeon invented a new and improved galvanometer and founded the first English journal to be devoted entirely to electricity. He died, however, as he had begun, in poverty. [437] SERTÜRNER, Friedrich Wilhelm Adam Ferdinand (sehr-tyoor'ner) German chemist
19, 1783 Died: Hameln, Saxony, February 20, 1841 Sertürner, whose father was Austrian, was apprenticed to an apothecary in 1798. In 1809, at which time Westphalia was part of Napoleon’s French Empire, Sertürner qualified to open his own pharmacy. Sertürner was interested in opium and tried to isolate that portion of the juice that induced sleep. In doing so, he dis covered morphine and laid the ground work for alkaloid chemistry. He was entirely self-taught and had some peculiar notions, a few mystical and useless, a few with some merit. He seems, in fact, to have been mentally dis turbed in later years. However, his dis covery of morphine was a remarkable job and, after some delay, its importance was recognized in his lifetime. [438] MAGENDIE, François (ma-zhabn- dee') French physiologist Born: Bordeaux, October 6, 1783 Died: Sannois, Seine-et-Oise, Oc tober 7, 1855 Magendie was the son of a surgeon of radical philosophic views, who was ac tive among the French revolutionaries. In 1799, the young Magendie was ap prenticed to a surgeon who was a friend of the elder Magendie. In 1803 Magen die entered his formal medical studies and obtained his M.D. at the University of Paris in 1808, studied anatomy at first, but then turned to physiology, where he was strongly antivitalist. Obsessed with a desire to experiment, he did so almost uncritically, to the extent that he gained a rather unpleasant repu tation as a vivisector. However, he es tablished experimental physiology and this, in the more analytical hands of his disciples, particularly in that of his most 295 [438] MAGENDIE
BESSEL [439] famous pupil, Claude Bernard [578], grew steadily in importance. Magendie was particularly interested in the nervous system and in 1825 was the first to deal in detail with the cere brospinal fluid. Working with puppies, he showed that the anterior nerve roots of the spinal cord were motor; that is, carried impulses to the muscles and led to motion. The posterior nerve roots were sensory; that is, carried impulses to the brain that were interpreted as sensa tion. This was confirmed by J. P. Müller [522], In 1815 Magendie had served as chair man of a commission investigating whether a nourishing food could be made out of the gelatinous extract of meat. (France had just undergone twenty years of revolution and war, and the plight of the poor was bad.) It was found that no nourishing food could be formed in this manner. Magendie’s ex periments continued in this field for a quarter century after the commission had done its work, and he was able to show that life could not be sustained in the absence of nitrogen-containing food stuffs (that is, protein) and that even some proteins, such as gelatin, were in sufficient. Magendie thus laid the groundwork for the modem science of nutrition and, in particular, for the work on essential amino acids which cul minated in the researches of Rose [1114] a century later. Despite Magendie’s fail ure, the age of modem food technology was fast approaching, with Borden [524] an early exemplar. Magendie also experimented with the action of various drugs on the human system. He introduced into medical prac tice the use of strychnine and morphine as well as compounds containing bro mine and iodine. He may therefore be considered the founder of experimental pharmacology. In 1830 he succeeded Laënnec [429] as professor of medicine at the Collège de France and established the first medi cal-school laboratory, something that rather disturbed his colleagues, who re tained a bit of the old notion that it demeaned a physician to dissect with his own hands. In 1837 he became president of the Academy of Sciences. He was not always right. He main tained (wrongly) that cholera was not contagious, and he objected to the use of ether as an anesthetic. And yet in 1839 he noted the suddenly heightened sensitivity to serum on a sec ond injection, something Richet [809] was to bring out in the full light of day six decades later. [439] BESSEL, Friedrich Wilhelm German astronomer Born: Minden, Prussia, July 22, 1784
Died: Königsberg, Prussia (now Kaliningrad, Soviet Union), March 17, 1846 Bessel, the son of a civil servant, began life as an accountant in Bremen but taught himself astronomy and math ematics and quickly did well at it. In 1804, at the age of twenty, Bessel recal culated the orbit of Halley’s comet and sent the results to Olbers [372], who was sufficiently impressed to obtain a post at an observatory for the young man in 1806. (In later years, Olbers would say that his discovery of Bessel was his greatest astronomic achievement.) By 1810 Bessel had grown prominent enough to attract the attention of King Frederick William III of Prussia, who appointed him to superintend the con struction of an observatory at Königs berg. He remained as director of that ob servatory until his death. In order to qualify for the post, by the way, and for the professorial dignity that went with it, Bessel needed a doctor’s degree and he was awarded it for the astronomical work he had already done. At the new observatory, Bessel worked industriously on the observations of James Bradley [258], in 1818 producing a new and excellent star catalogue con taining fifty thousand stars—later out done by his pupil Argelander [508], Bes sel introduced numerous refinements into astronomical calculations and worked out a method of analysis involving what are still called Bessel’s functions, applica 2 9 6
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