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401 [617] MORTON
STOKES [618] niche in the Hall of Fame for Great Americans. [617] MORTON, William Thomas Green American dentist Born: Charlton City, Massachu setts, August 9, 1819 Died: New York, New York, July 15, 1868 Morton may have graduated from the Baltimore College of Dental Surgery, the first dental school in the United States. He opened a dental practice in Boston and devised a new form of dental plate, which required that any remaining teeth be extracted first. Searching for a pain less way of doing this (and even investi gating the use of mesmerism for the pur pose), he approached a chemist and ex physician, C. T. Jackson [543], in 1844. From him, he heard of the effect of ether inducing unconsciousness and in sensibility to pain, and the idea struck him of using it in surgical operations. Actually, the idea of canceling pain was not new. Nearly half a century earlier Davy [421] had studied nitrous oxide and had speculated on its use fulness as an “anesthetic,” a term pro posed by Oliver Wendell Holmes [558]. Crawford W. Long [594] had made use of ether in surgery as early as 1842, and Morton’s notion came four years after that. Morton, however, did two things that his predecessors did not do. First, he pat ented the process in collaboration with Jackson. (Morton accepted this collabo ration since Jackson demanded a large fee for his advice and Morton had no money with which to pay.) Secondly, Morton publicized the matter. In September 1846 he extracted a tooth from a patient under ether and did it successfully. The next month he ar ranged to have a facial tumor removed from a patient under ether in the Massa chusetts General Hospital. The operating doctor, astonished, turned to the as sembled physicians when done and sol emnly said, “Gentlemen, this is no hum bug!” The success of that operation made anesthesia an essential adjunct of surgery and once and for all divorced the surgeon from the torture chamber. In England anesthesia was introduced by Simpson [567], who used chloroform. Morton had a great deal of trouble in attaining the fortune and the public grat itude he thought were his due because Jackson began a savage lifelong fight to claim the credit for the discovery of ether-anesthesia. Others made similar claims and Morton, abandoning dental practice, devoted his own life to these controversies. When a large sum of money was raised for Morton in Great Britain as an award for his discovery of anesthesia, Jackson raised such a fearful fuss that the offer was withdrawn. When a money award was offered by the French Acad emy of Medicine to both Morton and Jackson, Morton would not accept it. A bill introduced into the Congress of the United States for the purpose of appro priating $100,000 to give to Morton as a testimonial of national gratitude failed of passage in 1852, 1853, and 1854. Finally Morton died in poverty and of a stroke brought on, it is said, by his reading an article supporting Jackson’s claims. There never seems to be much difficulty about handing out posthumous gratitude, however, and Morton was elected to the Hall of Fame for Great Americans in 1920. [618] STOKES, Sir George Gabriel British mathematician and physi cist
gust 13, 1819 Died: Cambridge, England, Feb ruary 1, 1903 Stokes was the youngest child of a clergyman. He graduated from Cam bridge in 1841 at the head of his class in mathematics and his early promise was not belied. In 1849 he was appointed Lucasian professor of mathematics at Cambridge; in 1854, secretary of the Royal Society; and in 1885, president of the Royal Society. No one had held all three offices since Isaac Newton [231] a 402 [618] STOKES
FOUCAULT [619] century and a half before. Stokes’s vision is indicated by the fact that he was one of the first scientists to see the value of Joule’s [613] work. Between 1845 and 1850 Stokes worked on the theory of viscous fluids. He deduced an equation (Stokes’s law) that could be applied to the motion of a small sphere falling through a viscous medium to give its velocity under the influence of a given force, such as grav ity. This equation could be used to ex plain the manner in which clouds float in air and waves subside in water. It could also be used in practical problems in volving the resistance of water to ships moving through it. In fact such is the in terconnectedness of science that six dec ades after Stokes’s law was announced, it was used for a purpose he could never have foreseen—to help determine the electric charge on a single electron in a famous experiment by Millikan [969]. He also worked on fluorescence (a word he introduced in 1852), on sound, and on light. He studied ultraviolet radi ation by means of the fluorescence it produced. He was the first to show that quartz was transparent to ultraviolet ra diation, whereas ordinary glass was not. He also worked with the concept of the luminiferous ether through which light was supposed to travel, a concept that had been vexing physicists during the half century since the time of Fres nel [455]. Stokes tried to explain the ap parently contradictory properties of ether by suggesting it was like wax that would be firmly resistant to a hard, sud den blow, but would yield under a slow, steady force. (Thus, light would find the ether rigid, but a planet, moving much more slowly, would find it yielding.) He also suggested that the ether in the neighborhood of a moving planet would be dragged along with it. Such explana tions of the properties of the ether served to introduce new difficulties, how ever, and the whole matter came to a head shortly afterward with the work of Michelson [835]. In his lectures at Cambridge, Stokes announced interpretations of the sig nificance of the Fraunhofer [450] lines, which were in effect anticipations of the later theories of Kirchhoff [648]. Although Stokes never published his views, others tried to award him the credit. Stokes himself (whose character was warm with generosity and modesty) always insisted that he had not seen cer tain key points that were involved and that he could lay no claim to priority. In 1896, toward the end of his long life, Stokes was among the first to sug gest that X rays, newly discovered by Roentgen [774], were electromagnetic ra diation akin to light. Stokes received the Rumford medal of the Royal Society in 1852 and its Copley medal in 1893. He served as a Conser vative member in Parliament, sitting for Cambridge University, as once Newton had done, from 1887 to 1892, and was made a baronet in 1889. [619] FOUCAULT, Jean Bernard Léon (foo-koh') French physicist
Foucault, the son of a bookseller- publisher, had a sickly childhood and was privately educated. He finally en tered on medical studies and began his professional life as a physician but was an utter failure since, like Darwin [554], he couldn’t stand the sight of blood. In stead, he became a science reporter for an important newspaper. His articles did not always produce friends, and the cranky Leverrier [564] was, as a result of some of the things Foucault wrote, al ways hostile to him. Having met Fizeau [620], Foucault joined him and took up physics as his lifework. He collaborated with Fizeau in the measurement of the velocity of light by means of a toothed wheel, then devel oped an improved method of his own based on a suggestion advanced a decade earlier by Arago [446]. Imagine a ray of light striking mirror A and reflected at an angle to a second mirror, B, which reflects it in turn back to mirror A. If both mirrors were mo tionless, then the light would, in theory, bounce back and forth forever. If, how 403 [619] FOUCAULT
FOUCAULT [619] ever, mirror A is made to revolve rap idly, then when the light returns to it from mirror B, mirror A will have moved slightly and will reflect the light to a new position. From the speed with which mirror A revolves, from the total length of the light path, and from the angle by which the reflected beam of light is moved, Foucault could determine the velocity of light with hitherto un equaled accuracy. His value was more accurate than that of Fizeau and is just a trifle under the value ultimately obtained by Michelson [835], Foucault went further. He also made use of his mirror method to measure the velocity of light through water and other transparent media. As long before as the time of Huygens [215] and Newton [231], it had been suggested that one way of settling the dispute as to whether light was a wave form or a stream of particles was by measuring its velocity in water. According to the wave theory, light should slow down in water; accord ing to the particle theory, it should speed up. In 1853 Foucault showed that the velocity of light was less in water than in air, a strong piece of evidence in favor of the wave theory. He presented this work as his doctoral thesis. Foucault’s name is most often as sociated with a spectacular series of ex periments that began in 1851. Foucault knew that a pendulum had a tendency to maintain the plane of its oscillation, however the point of its attachment might be twisted. Foucault saw then that if a large pendulum were set in motion it would maintain its plane of oscillation while the earth twisted under it. If the pendulum were at the North Pole the earth would make a complete twist be neath it in twenty-four hours. At more southerly latitudes the earth would seem to twist more slowly, as areas to the north traveled at a slightly slower veloc ity than areas to the south. This velocity difference would become less as one traveled south and at the equator there would be no twist at all. South of the equator the twist would begin again (but in the opposite direction) and would have a period of twenty-four hours again at the South Pole. To someone watching the pendulum (and himself partaking of the motion of the earth) it would seem as though the pendulum were slowly changing direc tion. Foucault’s first experiment was in decisive. A longer pendulum was needed. First Arago offered the use of the obser vatory building for a second test, and then Napoleon III arranged to have a large Paris church used for the third and most famous test. Foucault suspended a large iron ball about two feet in diameter from a steel wire more than two hundred feet long, under the dome of the church. The pendulum ended in a spike that just cleared the floor but would score a mark in the sand with which the floor of the church was sprinkled. The iron ball was drawn far to one side and tied to the wall by a cord. Every attempt was made to keep the air and the building free of vibrations that might disturb the steady swing of this tremendous pendulum. When all was quiet, the cord holding the pendulum was set on fire. (If it had been cut by scissors or knives, vibrations would have interfered with the experiment.) The cord broke, the pendulum began its swing, and a large audience caught and held its breath. As time went on, the mark made by the pendulum spike visi bly changed its orientation. It twisted in the direction and at just the rate that was to be expected for the latitude of Paris, one rotation in 31 hours, 47 minutes. The spectators were actually watching the earth rotating under the pendulum. The experiment caused great excite ment at the time. Heracleides [28] had first suggested twenty-two centuries be fore that the earth was rotating and Copernicus [127] had renewed the sug gestion three centuries before. Since the time of Galileo [166] two and a half cen turies before, the world of scholarship had not doubted the matter. Never theless, all evidence as to that rotation had been indirect, and not until Fou cault’s experiment could the earth’s rota tion actually be said to have been dem onstrated rather than deduced. A massive sphere in rotation, like a pendulum, has a tendency to maintain
[620] FIZEAU
FIZEAU [620] the direction of its axis of spin, as the earth does. Foucault demonstrated this point, which had been established theo retically, by an experimental demon stration. In 1852 he set a wheel with a heavy rim into rapid rotation. It not only maintained its axial direction (and could be used to demonstrate the rotation of the earth) but if it was tipped the effect of gravity was to set up a motion at right angles that was equivalent to the preces sion of the equinoxes. In doing this, Foucault had, incidentally, invented the gyroscope. In 1857 Foucault developed the mod em technique for silvering glass to make mirrors for reflecting telescopes. This meant glass could be used instead of metal. Mirrors became much lighter, less likely to tarnish and easier to renew if tarnished. For the first time since New ton’s invention, reflecting telescopes took a clear lead over refracting ones. At one point Foucault scored a miss. He saw the significance of the fact that the solar spectrum showed a dark line just where the sodium light showed a bright one. In fact it was upon Fou cault’s work that Stokes [618] based his lectures on the significance of the Fraun hofer [450] lines. However, neither Fou cault nor Stokes carried matters far enough and it was Kirchhoff [648] who, a few years later, was to develop spec troscopy. In the 1840s though, Foucault was one of the first to make micropho tographs. Foucault led an uneventful life, and was interested only in his work (too much so, apparently, for overwork seems to have made him an invalid and con tributed to his early death). [620] FIZEAU, Armand Hippolyte Louis (fee-zohO French physicist Born: Paris, September 23. 1819 Died: Venteuil, Seine-et-Mame, September 18, 1896 Fizeau was one of those fortunates bom into wealth who can pass their lives in pleasure, and the world is fortunate that there are some of those who find their pleasure in scientific research. Since his father was an eminent pathol ogist, it isn’t surprising that Fizeau tried at first to study medicine, but like Fou cault [619], with whom his name is so often linked, he was not cut out for it and eventually realized his bent was to ward physics. Fizeau’s overriding interest was light, and he was the first to measure its veloc ity by a terrestrial method. Up to the mid-nineteenth century, light’s velocity had been measured only by Roemer [232] and Bradley [258], each using an astronomical method. Fizeau, however, refined Galileo’s [166] unsuccessful method of flashing lights back and forth from adjacent hills. In 1849 Fizeau set up a rapidly turn ing toothed disc on one hilltop and a mirror on another, five miles away. Light passed through one gap between the teeth of the disc to the mirror and was reflected. If the disc turned rapidly enough, the reflected light passed through the next gap. From the speed of revolution at which light was first suc cessfully reflected, the time required for light to travel ten miles could be calcu lated.
The experiment was a success and the velocity of light was determined to be a value that we now recognize to be some 5 percent too high. This was corrected by the improved method of Foucault the next year. Fizeau also considered what was to be expected of light from a moving source. Doppler [534] had already done this, since he had worked out matters well for sound, but he had come to erroneous conclusions. In 1848 Fizeau pointed out that the lines in a spectrum ought to shift toward the red if the light source is receding and toward the violet if it is approaching. It was two decades before instrumentation advanced to the point of being able to take advantage of this anal ysis, but finally Huggins [646] was able to measure the velocity at which a star was approaching toward or receding from the earth. Fizeau, by the way. had married the daughter of Jussieu [345]. 405 [621] FIELD
BECQUEREL [623] [621] FIELD, Cyrus West American businessman
setts, November 30, 1819 Died: New York, New York, July 12, 1892 Field was the younger brother of a fa mous lawyer who pioneered in the field of international law. He began life as an errand boy and, though he never became in any sense of the word a scientist, he had the vision and daring to carry through a dramatic application of nine teenth-century science, an application that nowadays would be supported by governments rather than single individ uals. Over a thirteen-year period Field dissipated his fortune (made in the paper business) and withstood disaster upon disaster in his determined attempt to lay an Atlantic cable. He supplied the money and the drive; Maury [548] sup plied the oceanographic know-how, and Kelvin [652] supplied the electrical. Field’s efforts were finally successful and the United States and Europe were united by electrical signals in 1866. Field’s reward was a gold medal and a vote of thanks from Congress. Later, Field interested himself in building New York City’s elevated railways, where he lost another fortune, particularly through the shady dealings of some financiers. He died poor. [622] BEGUYER DE CHANCOUR- TOIS, Alexandre-Émile (buh-gee- ay' duh shan-koor-twah') French geologist Born: Paris, January 20, 1820 Died: Paris, November 14, 1886 Beguyer de Chancourtois, the grand son of a noted artist, was a geologist who had carried his field explorations from Greenland to Turkey. As inspector general of mines in France, he had en forced safety measures over the protests of mine owners. In 1862 he ventured into chemistry and arranged the elements in order of atomic weights. He plotted them about a cylinder, finding that similar elements fell in vertical lines. He published a paper describing this but was a rather bumbling writer and used geological terms that made little sense to chemists. As if this were not enough to assure oblivion for the paper, the journal publishing it did not see fit to reproduce his diagram of the elements wound about the cylinder or the “telluric helix,” as he called it. The diagram might have explained his points; without it, the paper was impossible. Beguyer de Chancourtois, like New- lands [727], lived to see Mendeleev [705] produce the periodic table and gain the credit. Unlike Newlands, he did not live to see his own vindication. In the 1890s the journal in which his paper originally appeared finally published his diagram. [623] BECQUEREL, Alexandre Edmond (beh-krel') French physicist Born: Paris, March 24, 1820 Died: Paris, May 11, 1891 Becquerel was the son of a professor of physics at the Paris Museum of Natu ral History and worked with him there. He received a doctor’s degree from the University of Paris in 1840 and gained a professorial position at the Agronomic Institute of Versailles. He investigated electricity and magne tism, where his most significant discov ery was the magnetic property of liquid oxygen. He showed, in 1840, that light, by inducing certain chemical reactions, could produce an electric current and devised an instrument that measured light intensity by determining the inten sity of the electric current produced. He also devised a way of measuring the heat of objects hot enough to give off visible light by determining the intensity of that light. He was particularly interested in fluorescence, the phenomenon whereby certain substances absorb light of one wavelength and then re-emit light of an other. This is particularly marked when the light absorbed is ultraviolet and the light emitted is in the visible range. Download 17.33 Mb. Do'stlaringiz bilan baham: 
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