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561 [869] THOMSON
THOMSON [869] but his father’s early death made it im possible to pay the extra fees required, so he grew interested in physics instead. In 1876 he entered Cambridge on a schol arship and there he was to remain for the rest of his life. He finished second in his class in mathematics and in 1884, when he was only twenty-seven, he suc ceeded Rayleigh [760], on the latter’s re tirement, as professor of physics. He be came director of the Cavendish Labora tory in 1884, succeeding Rayleigh there too, and remained its head for a genera tion—till 1919. It was largely due to his direction and inspired teaching that En gland maintained clear leadership in the field of subatomic physics for the first three decades of the twentieth century. Thomson was initially interested in Maxwell’s [692] theories of electromag netic radiation, and this led him on to the cathode rays as a novel form of radi ation that was not electromagnetic in character. Crookes [695] and others had presented evidence that the cathode rays consisted of negatively charged particles, pointing to the deflection of the rays by a magnetic field. The demonstration, however, remained inconclusive because no one could show the rays to be also affected by an electric field, as they would have to be if they were charged particles. Thomson worked with very highly evacuated tubes and was finally able, in 1897, to show cathode-ray deflection in an electric field, the final link in the chain of evidence. The cath ode rays were accepted thereafter as par ticulate in nature. Furthermore, Thomson measured the ratio of the charge of the cathode-ray particles to their mass. It turned out that if the charge were equal to the minimum charge on ions as worked out by the laws of electrochemistry first expounded by Faraday [474], then the mass of the cathode-ray particles was only a small fraction (now known to be 1/1837) of that of hydrogen atoms. The cathode-ray particles were thus far smaller than atoms and Thomson had opened up the field of subatomic particles. The cathode-ray particles were ac cepted as units of electrical current. The name earlier proposed by Stoney [664] for a hypothetical unit of electrical cur rent was electron, and Lorentz [839] applied it to the particles over Thomson’s objections. Since Thomson was the one who supplied the final proof for the ex istence of such particles in cathode rays and since he was the first to offer evi dence of their subatomic size, he is usually considered the discoverer of the electron. Thomson viewed the electron as a uni versal component of matter and was one of the first to suggest a theory as to the internal structure of the atom. He believed that the atom was a sphere of positive electricity in which negatively charged electrons were embedded (like raisins in pound cake) in just sufficient quantity to neutralize the positive charge. This theory, although a good be ginning, was quicldy replaced by the far more useful one advanced by Thomson’s student Rutherford [996], In 1906 Thomson was awarded the Nobel Prize in physics for his work on the electron and in 1908 he was knighted. (Subsequently, no fewer than seven of his research assistants were to win Nobel Prizes.) After 1906 Thomson interested him self in the “channel rays,” which Gold stein [811] had discovered. These were streams of positively charged ions, so Thomson named them positive rays. Thomson deflected them by magnetic and electric fields in such a way as to cause ions of different ratios of charge to mass to strike different portions of a photographic plate. In so doing he found in 1912 that ions of neon gas fell on two different spots, as though the ions were a mixture of two types, differing in charge, mass, or both. Soddy [1052] had already suggested the existence of isotopes, that is, of atom varieties of a single element, differing in their mass. Here Thomson had the first indication that ordinary ele ments might also exist as isotopes. Thomson’s pupil Aston [1051] was to carry this research further and he es tablished the fact. Thomson died on the eve of the Battle of Britain, when England’s fortunes seemed lower than at any time in his tory. He was buried in Westminster
[870] KITASATO
JOHANNSEN [872] Abbey, near the remains of Newton [231]. [870] KITASATO, Baron Shibasaburo (kee-tah-sah-toh) Japanese bacteriologist Born: Oguni, Kumamoto, December 20, 1856 Died: Nakanojo, Gumma, June 13, 1931 After graduation from the medical school of the University of Tokyo in 1883, Kitasato, the son of a village mayor, left for Germany to study under Koch [767], with whom he worked from 1885 to 1891. He was a most successful student, for he isolated the bacillus caus ing tetanus and another causing anthrax in 1889. He collaborated with Behring [846] in his work. He returned to Tokyo in 1892 and there had ample opportunity to continue the study of disease. An outbreak of bubonic plague in Hong Kong in 1894 gave him the opportunity to isolate the agent causing that disease, and in 1898 the agent causing dysentery. He was made a baron in 1924. [871] MOHOROVKie, Andrija (moh- hoh-roh-vee'cheech) Croatian geologist
23, 1857 Died: Zagreb, December 18, 1936
Mohorovicic, the son of a shipwright, entered the University of Prague, where he attended lectures by Mach [733], He received a post at the Royal Nautical School at Bakar, where he taught meteo rology.
He grew increasingly interested in seis mology. Studying the wave patterns set up by a Balkan earthquake in 1909, Mohorovicic deduced the fact that the earth possessed a layered structure. Waves that penetrated deeper into the earth arrived sooner than waves traveling along the surface, even allowing for the difference in distance traversed. Mo horovicic maintained that the earth’s out ermost crust rested on a layer that is more rigid and in which earthquake waves traveled more quickly. Further more, the separation between the two layers does not seem to be gradual, but is sharp. The separation is now called the Mohorovidic discontinuity and it is known to lie from ten to forty miles below sea level. (Americans dodge the Slavic name by speaking of it as the Moho discontinuity.) The discontinuity is nearest the surface under the deep ocean basins, where, moreover, a great deal of the distance separating it from the sea level is just water. Attempts were considered in the 1960s to penetrate the three or so miles of solid crust under chosen spots in the ocean floor in order to reach this discon tinuity and study the nature of the layer below. The name of the penetration planned still bears a piece of the geolo gist’s name, for it is the Mohole. [872] JOHANNSEN, Wilhelm Ludwig (yoh-han'sun) Danish botanist Born: Copenhagen, February 3, 1857
Died: Copenhagen, November 11, 1927 Johannsen, the son of a Danish army officer, could not afford a university edu cation and, in 1872, was apprenticed to a pharmacist but continued his program of self-education in chemistry and biol ogy. In 1881 he worked as an assistant in the chemistry department at Carlsberg under Kjeldahl [801]. He reached profes sorial rank in 1903 and in 1917 was rec tor of the university, though still without a formal education. He is another one of those scientists whose fame in the history of science rest chiefly on the invention of a word. After Mendel’s [638] work had been rediscovered by De Vries [792] in 1900, the former’s factors of inheritance be came matters of intense importance to biologists. In 1909 Johannsen suggested they be called “genes” from a Greek word meaning “to give birth to.” The suggestion was adopted and from it 563 [873] HERTZ
HERTZ [873] other words such as “genotype” and “ge netics” arose. [873] HERTZ, Heinrich Rudolf German physicist
1857
Died: Bonn, January 1, 1894 After starting his studies in engineer ing, Hertz, a Lutheran who was the son of a Jewish lawyer, abandoned that for physics, studying at the University of Berlin under Helmholtz [631] and Kirchhoff [648]. He obtained his Ph.D.
for two years more as Helmholtz’s assis tant. He maintained a strong friendship with Helmholtz which remained lifelong, for the sadly short-lived Hertz was sur vived by the older Helmholtz by nearly a year. Working at the University of Kiel in 1883, Hertz grew interested in the equa tions governing the electromagnetic field that had been worked out by the then recently deceased Maxwell [692], The Berlin Academy of Science was offering a prize for certain work in the field of electromagnetics and Helmholtz sug gested to his young protégé that he take a stab at it. Hertz, who by then had a professorial position at a school in Karlsruhe, got to work without too much enthusiasm, but in the course of that work he succeeded, in 1888, in finding something that went far beyond anything for which he had been searching. He had set up an electri cal circuit that oscillated, surging into first one, then another, of two metal balls separated by an air gap. Each time the potential reached a peak in one di rection or the other, it sent a spark across the gap. (In the course of these experiments, he noted that when ultravi olet light shone on the negative terminal of the gap, the spark was more easily elicited. He did not follow that up, but this was the first observation of the pho toelectric effect, which, a generation later, Einstein [1064] was to explain, earning a Nobel Prize thereby.) With such an oscillating spark, Max well’s equations predicted, electromag netic radiation should be generated. Each single oscillation should produce one wave, so that the radiation would be ex pected to be of extremely long wave length. After all, since light travels at 186,282 miles a second, a wavelength formed in an oscillation of a mere thou sandth of a second would still be over 186 miles long. Hertz used, as a device for detecting the possible presence of such long-wave radiation, a simple loop of wire with a small air gap at one point. Just as cur rent gave rise to radiation in the first coil, so the radiation ought to give rise to a current in the second coil. Sure enough, Hertz was able to detect small sparks jumping across the gap in his de tector coil. By moving his detector coil to various points in the room, Hertz could tell the shape of the waves by the intensity of spark formation and could calculate the wavelength as 66 centime ters (2.2 feet). This is a million times the size of a wavelength of visible light. He also managed to show that the waves involved both an electric and a magnetic field and were therefore electromagnetic in nature. He thought at first they might travel at only two-thirds the speed of light but this proved an error and was soon corrected. In this way Hertz verified the use fulness of Maxwell’s equations. Hertz’s experiments were quickly confirmed in England by Lodge [820], while Righi [810] in Italy demonstrated the rela tionship of these “Hertzian waves” to light. When Marconi [1025] devised a practical means for using these waves as a form of wireless communication, they came to be called radio waves. (Actu ally, “radio” is short for “radioteleg raphy”; that is, telegraphy by radiation as opposed to telegraphy by electric cur rents. )
In 1889 Hertz succeeded Clausius [633] as professor of physics at the Uni versity of Bonn. There he worked on cathode rays, which he believed were waves and not particles because they penetrated thin metal films; it did not seem to him particles would be able to do so. He might have lived to see radio become an important factor in human
[874] WAGNER VON JAUREGG ROSS
society. However, he did not even wit ness its beginnings. Nor did he witness the discovery of the electron by J. J. Thomson [869], who showed it to be a particle far smaller than the atom, and therefore one that, not surprisingly after all, could easily penetrate ordinary mat ter. Hertz died, after a long illness due to chronic blood poisoning, before his thirty-seventh birthday. [874] WAGNER VON JAUREGG, Julius (vahg'ner-fun-yoo'rek) Austrian psychiatrist Born: Weis, Upper Austria, March 7, 1857 Died: Vienna, September 27, 1940
Wagner von Jauregg, the son of a civil servant, obtained a medical education at the University of Vienna, met Freud [865] while still a student, and es tablished a lifelong friendship with him. Wagner von Jauregg found his way into psychiatry somewhat by accident but by 1887 was a qualified teacher in the field, and in 1889 succeeded Krafft-Ebing [749] as a professor of psychiatry at the University of Graz. Wagner von Jauregg achieved his best- remembered claim to fame when he no ticed that patients with advanced syphilis sometimes improved after they had suffered from diseases that were accom panied by high fever. The high tempera ture apparently damaged the germ caus ing syphilis. It occurred to Wagner von Jauregg, therefore, that patients far gone in syphilis might deliberately be infected with malaria. The malarial fever could greatly ameliorate the syphilis, while the malaria itself could be controlled by qui nine. He tried this for the first time in 1917 and by and large it worked. The method was widely adopted and in 1927 earned him the Nobel Prize for physiology and medicine. The malaria treatment of syphilis did not long endure; it has been replaced by antibiotics. However, it was the fore runner of shock treatment for a variety of mental ailments. [875] PEARSON, Karl English mathematician
27, 1936 Pearson, the son of a lawyer, studied at Cambridge under Stokes [618], Max well [692], and Cayley [629], and in 1879 graduated third in his class in mathematics. He eventually went on to qualify in law, but never practiced. He obtained a professorship in applied mathematics at University College, Lon don, in 1884. During postgraduate studies in Ger many he had attended lectures by Du Bois-Reymond [611] on Darwin’s evolu tionary thinking, and had grown inter ested. The writings of Gal ton [636] on heredity interested him further. He began to apply mathematics to the ran dom processes of heredity and evolution and in so doing served as the founder of modern statistics. Among other things he evolved the chi-square test of statistical significance. His work in this direction was carried on by Fisher [1142]. [876] ROSS, Sir Ronald English physician Born: Almora, India (near Nepal), May 13, 1857 Died: London, September 16, 1932
Ross was born of an Anglo-Indian family and first saw England at the age of eight. He received his education in England and obtained his medical degree in 1879. In 1881, however, he entered the Indian Medical Service and returned to India, where he served in a British military campaign in Burma in 1885. There (in addition to writing novels, plays, and poems) he grew interested in malaria and in the suggestion that mos quitoes might play a role in transmitting it. Despite the hampering effect of his military service he devoted himself to collecting, feeding, and dissecting mos quitoes.
Finally, in 1897, he located Laveran’s [776] malarial parasite in the Anopheles 565 [877] ABEL
BINET [878] mosquito. Ross’s discovery meant that it was rational to launch a systematic at tack on the breeding places of mosqui toes as a way of wiping out malaria. There was reason for efforts as small as using netting at night and as great as draining swamps. Ross returned to England and was eventually a professor of tropical medi cine, first at Liverpool, then at King’s College in London. He was rewarded with the 1902 Nobel Prize in medicine and physiology. He was knighted in 1911. The attack on insects has continued ever since and a half century after Ross’s time, new weapons were discovered by Paul Miiller [1216] and others in the form of powerful insecticides. [877] ABEL, John Jacob American biochemist Born: Cleveland, Ohio, May 19, 1857
Died: Baltimore, Maryland, May 26, 1938 Abel, the son of a prosperous farmer, got his undergraduate training at the University of Michigan, graduating in 1883. He then went to Germany for his graduate training, remaining there for six years, and studied under men such as Ludwig [597]. He got his Ph.D. in 1888 and his M.D. in 1890. On his return to the United States, he had a professorial appointment first at the University of Michigan, then at Johns Hopkins Uni versity.
In 1897 he was the first to isolate an active molecule from the adrenal me dulla. He called it epinephrine, though it later came to be better known as by the trade name Adrenalin or as adrenaline. Abel’s compound was not, however, the hormone itself, but a somewhat more complicated analogue. It was Takamine [855] who obtained the bare hormone soon afterward. He was also interested in another hor mone, insulin, which had come into par ticular prominence with the work of Banting [1152]. In 1925 Abel prepared insulin in crystalline form for the first time. This was an important step in pre paring pure and reproducible solutions of this important substance. Then, too, in 1912, he was the first to work on an artificial kidney and even managed to produce one that could be useful in laboratory work. [878] BINET, Alfred (bee-nayO French psychologist Bom: Nice Alpes-Maritimes, July 8, 1857
Died: Paris, October 18, 1911 At the time of Binet’s birth, Nice was part of the Italian-speaking kingdom of Sardinia, so that Binet was not, strictly speaking, French. However, Nice was ceded to France before Binet’s third birthday. In 1871 he went to Paris for his education and studied medicine and law. In the 1880s he grew interested in psychology and in the uses of hypnotism, much as Freud [865] was to be doing in Vienna shortly afterward. In 1891 he be came associated with the Sorbonne in Paris, and in 1894 he became director of its psychology laboratory. Binet, however, was concerned more with the normal workings of the mind than with the abnormal; and, in particu lar, in measuring human intelligence ob jectively. Tests of various sorts had al ways been used to determine the prog ress a student was making in his studies, but Binet wanted more than that. He wanted to test those facets of human ability that did not depend on specific in structions in one field or another or upon the memorization of facts. He wanted to measure the innate ability of a mind to think and reason. For this he designed various tests which asked children to name objects, to follow commands, to rearrange disor dered things, to copy designs, and so on. In 1905 he and his associates published the first batteries of tests designed to measure intelligence, and in 1908 others were published. The value was tested empirically. If a particular test was passed by some 70 percent or so of the nine-year-olds in the Paris school system, 5 6 6
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