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696 [1096] BLACK
SVEDBERG [1097] It was known that muscle contained glycogen, the substance Bernard [578] had discovered in liver over half a cen tury before. Hopkins [912] and his co workers had shown, the decade before, that working muscle accumulated lactic acid. Meyerhof, in a series of careful ex periments, showed that there was a quantitative relationship between the gly cogen that disappeared and the lactic acid that appeared and that in the pro cess oxygen was not consumed. What was taking place, then, was anaerobic glycolysis (“glycogen-breakdown without air”). Meyerhof also showed that when muscle rested after work, some of the lactic acid was oxidized (molecular oxy gen being then consumed to pay off what the physiologists called the “oxygen debt”). The energy so developed made it possible for the major portion of the lac tic acid to be reconverted to glycogen. Meyerhofs work initiated the labors, carried on later by the Coris [1192, 1194], that worked out the detailed steps whereby glycogen is converted to lactic acid and this is therefore known as the “Embden-Meyerhof pathway” after him self and a co-worker. For this work Meyerhof was awarded the 1922 Nobel Prize in medicine and physiology, shar ing it with Hill [1108]. Under the Hitler regime Meyerhofs position in Germany grew increasingly uncomfortable. In 1938 he left for France, and in 1940, when that country fell to the Germans, he was forced to flee again, this time to the United States, where he joined the faculty of the Uni versity of Pennsylvania in Philadelphia. In 1948 he qualified for citizenship and the last three years of his life were there fore spent as an American. [1096] BLACK, Davidson Canadian anthropologist Born: Toronto, Ontario, July 25, 1884
Died: Peking, China, March 15, 1934
Black, the son of a lawyer, chose a medical career and obtained his M.D. at the University of Toronto in 1909. After teaching at Western Reserve University (now Case-Western Reserve University) in Cleveland as an anatomist, he grew interested in anthropology. He worked in England and the Netherlands in the field and then decided it must be Asia that was the home of early ancestors of hu manity. In 1920, he took a post at the Peking Union Medical College in order to ad vance his investigations. Twenty-five miles west of Peking at Chou K’ou-tien, in 1927, he located a single human molar. From this tooth alone, he de duced the existence of a small-brained ancestor he called Sinanthropus pekin-
came to be popularly known as Peking man. Other teeth were found then in 1929 and 1930, skulls were found, together with other bones, tools, and remains of campfires. Peking man, very much like Dubois’s [884] Java man, is now consid ered an example of Homo erectus, ancestral to Homo sapiens. [1097] SVEDBERG, Theodor H. E. (svayd-bare'y) Swedish chemist
August 30, 1884 Died: Stockholm, February 25, 1971
Svedberg, the son of a civil engineer, studied at the University of Uppsala, graduated and joined its faculty in 1907, becoming professor of physical chemis try in 1912. Svedberg was chiefly interested in the chemistry of colloids and during his stu dent years he prepared colloidal suspen sions of metals by setting up electric arcs between metal electrodes under water. As was the case for that other colloid chemist, Zsigmondy [943], Svedberg in vented a new tool for studying them. Colloid particles are so small that the incessant banging of water molecules is enough to keep them from settling out. If only gravitational force were more in tense than it is, molecular collisions of 697 [1097] SVEDBERG
RORSCHACH [1099] the solvent would not be enough and the colloidal particles would then settle out, the largest ones fastest. It is, of course, impossible with pres ent-day techniques to alter the gravita tional field itself, but Svedberg could make use of an effect that resembled gravitation—the centrifugal effect Cen trifuges were already being used to sepa rate milk from cream and blood corpus cles from blood plasma. However, cells and fat droplets are relatively large. To force the much tinier colloid particles out of solution, much stronger centrif ugal effects were necessary. For the pur pose Svedberg developed the ultracen trifuge in 1923. (Such an ultracentrifuge can be made to whirl so fast that an effect equivalent to hundreds of thou sands of times normal gravity is devel oped.)
Colloidal particles did indeed settle out. From the rate of settling, the size of the particles and even the shape could be deduced, while a mixture of two dif ferent types of particles could be sepa rated.
This turned out to be most important in the case of protein molecules. The protein molecule is a giant of the molec ular world and, all by itself, is of colloi dal size. For that reason, proteins, even though going completely into solution, remain colloidal in their properties. The individual protein molecules settle out neatly in the ultracentrifuge, however, and it was in this way that the molecular weight of the larger proteins could be determined (from the rate of settling) for the first time. Later, the technique proved useful for other giant molecules too, such as the synthetic polymers whose molecular properties were studied by Staudinger [1074]. For this and for his other work on colloids Svedberg was awarded the 1926 Nobel Prize for chemistry. In later years he collaborated with his student Tiselius [1257] in working out modem methods of electrophoresis that have proved at least as important as ultracentrifugal methods in studying proteins. Svedberg was director of the Institute for Physical Chemistry at Uppsala. [1098] BERGIUS, Friedrich Karl Rudolf (behrigee-oos) German chemist Born: Goldschmieden, Silesia (now part of Poland), October 11, 1884
March 30, 1949 Bergius’s father was head of a chemi cal factory, and so Bergius was following in family tradition by becoming inter ested in industrial chemistry. He studied under Nemst [936] and Haber [977], gaining his doctorate at the University of Leipzig in 1907. From Haber he developed an interest in reactions under pressure and worked out methods of treating coal and heavy oil with hydrogen to form gasoline, being guided in part by data that had been gathered by Ipatieff [966]. He first ac complished this in 1912, but the evolu tion from laboratory demonstration to practical industrial process took twelve years. He also discovered methods of breaking down the complicated mole cules of wood to simpler molecules, which could, in turn, be made to un dergo chemical reactions that produced alcohol and sugar. For his work on high- pressure processes he shared with Bosch [1028] the 1931 Nobel Prize in chemis try. Germany, during World War II, used the Bergius processes to supply herself with gasoline and to make a certain amount of edible material out of wood. After the war Bergius did not wish to remain in defeated Germany. He moved first to Austria, then Spain, and finally to Argentina, where he served the govern ment of that country as technical ad viser. However, he died about a year after he arrived in Argentina. [1099] RORSCHACH, Hermann (rawri- shahkh)
Swiss psychiatrist Born: Zürich, November 8, 1884 Died: Herisau, April 2, 1922 Rorschach, the son of an art teacher, took his medical training at the Univer
[1100] HEVESY
HE VE SY [1100] sity of Zürich, and was drawn into psy chiatry by his interest in Jung’s [1035] theories. Rorschach the man is buried almost entirely in the technique he devised for diagnosing psychopathological condi tions.
This involved the use of ten symmet rical inkblots, which the patient was asked to interpret. From the inter pretations (the Rorschach test) it was presumably possible to tell a great deal about the patient. This technique has proved very popu lar, although it is difficult to tell how much validity there can be to it. [1100] HEVESY, Gy orgy (heh'veh-shee) Hungarian-Danish-Swedish chemist
Born: Budapest, August 1, 1885 Died: Freiburg-im-Breisgau, Germany, July 6, 1966 Hevesy came of a wealthy family and he called himself “von” Hevesy in Ger many. He was educated in Hungary and in Germany. He received his Ph.D. in 1908 from the University of Freiburg. He worked with Haber [977] for a while, then traveled to England for work with Ernest Rutherford [996]. He served in the Austro-Hungarian army in World War I, but in the chaos of defeat left for Bohr’s [1101] labora tory in Copenhagen in 1920. Hevesy’s two great contributions were both made in 1923 and the less dramatic was by far the more important. The search for new elements, it seemed, was petering out in the twenti eth century. Dozens had been discovered in the nineteenth but the field was nar rowing. Mendeleev’s [705] periodic table had been rationalized by the X-ray stud ies of Moseley [1121] and the theories of atomic structure that Bohr had put forth. From this rationalization one could see that there was an opening for an as yet undiscovered element corresponding to atomic number 72. Bohr suggested that the undiscovered element be sought for in ores of the metal zirconium, just above atomic num ber 72 in the periodic table. In January of 1923 the new element was found by Hevesy and a colleague. Its newness was verified by X-ray analysis in the manner worked out by Moseley, and it was named hafnium, from the Latinized name of Copenhagen. So much for the more dramatic discovery. Hevesy was also interested in using ra dioactive atoms to study living systems. Radioactive atoms could be detected eas ily, even when present only in small traces, through the energetic radiations they threw out in all directions. Hevesy began by using a radioactive isotope of lead, obtained from thorium breakdown products. Working under Rutherford, he had failed to find any chemical difference between radioactive and ordi nary lead, and now he planned to make use of this lack of difference. In 1918 he used it to determine the solubility of lead salts, since the presence of even minute traces of radioactive lead in water could be detected easily and he could then assume that ordinary lead dis solved to the same extent that radioac tive lead did. Then, again, by watering plants with solutions containing the radioactive isotope, he was able in 1923 to follow the absorption and distribution of lead in great detail. It might have been fair to assume that what was true of lead would be true of substances in general, but it was not. Lead is not a normal component of liv ing systems (indeed it is highly poison ous) and it would be unsafe to general ize from lead-poisoned plants to all plants. However, the principle had been established. If an isotope could be found which, except for its radioactivity, was a normal component of living tissue, then one might follow its trail of radiation with a feeling that it did represent the normal pathways, both physiological and chemical, within the organism. After the discovery of artificial radio activity by the Joliot-Curies [1204, 1227], just such isotopes were developed and the principle of isotopic “tracers” was firmly established. Indeed, without such tracers it is hard to see how the network of metabolic reactions within living 699 [1101] BOHR
BOHR [1101] tissue could possibly have been straight ened out to the extent that it now is. Hevesy’s use of radioactive tracers for the first time made no splash in 1923, but by the time a pair of decades had passed, the importance of the step was manifest. In 1926 Hevesy moved to Germany, accepting a professorship at the Univer sity of Freiburg. When Hitler came to power, Hevesy went back to Copenha gen, and when the Nazis occupied Den mark in 1940, Hevesy managed to es cape to Sweden in 1942. There he taught at the University of Stockholm. While there he was awarded the 1943 Nobel Prize in chemistry. In 1959 he received the Atoms for Peace Award. Eventually, he returned to Germany and there he died. [1101] BOHR, Niels Henrik David Danish physicist
1885
Died: Copenhagen, November 18, 1962 Bohr, the son of a physiology profes sor, entered the University of Copenha gen in 1903, where he studied physics and was also a crackerjack soccer player. (His younger brother was even better and made the 1908 Danish Olympic soccer team, which took a second place.) Bohr received his doctorate there in 1911. The next year, he obtained a grant to travel abroad in order to further his education and went at once to Cam bridge, where he worked under J. J. Thomson [869], and then to Manchester, where he worked under Ernest Ruther ford [996], He married in 1912 (and eventually had five sons) and in 1916 he returned to the University of Copenha gen as professor of physics. Rutherford had put forth the notion of the nuclear atom; that is, of an atom containing a tiny massive nucleus at its center with a cloud of light electrons lo cated on the periphery. It seemed to Bohr, while yet at Cambridge, that if this internal structure of the atom were com bined with the quantum theory put out 7 0 0 by Planck [887] a little over a decade be fore, then perhaps it would be possible to explain how substances emitted and absorbed radiant energy. This absorption and emission was of vital importance in spectroscopy for it accounted for the spectral lines that had been discovered by Fraunhofer [450] a century earlier and put to use by Kirchhoff [648] a half century after that. Through all the past century, however, scientists had been content to measure the position of the lines without attempting to explain why a line should be located in one place rather than another. Bohr attempted to rectify this omission and happened to come across Balmer’s [658] formula for the hydrogen spec trum. He began, then, to consider the hydrogen atom, which was the simplest of all. In 1913 he had his scheme. He suggested that the single electron of the hydrogen atom did not radiate elec tromagnetically as it oscillated within the atom as Lorentz [839] had suggested in 1895. At first thought it would seem it must, according to the equation of Max well [692], from which it appeared that electromagnetic radiations were pro duced whenever an electric charge such as that on an electron was accelerated, as when the electron moved in a closed orbit. Nevertheless, Bohr maintained that radiation was not emitted as long as it stayed in orbit. (The apparent contra diction was resolved the next decade when De Broglie [1157] showed that the electron was not merely a particle but a wave form and Schrödinger [1117] worked out a theory where the electron was not revolving about the nucleus but was merely a “standing wave” formed about it. The electron in a particular orbit was therefore not accelerating and did not have to radiate.) Radiation was emitted, Bohr pointed out, when the electron changed its orbit and approached closer to the nucleus. On the other hand, when radiation was absorbed, the electron was driven into an orbit farther from the nucleus. Thus, electromagnetic radiation was produced by shifts in “energy levels” in subatomic particles and not by oscillations or accel erations of those particles. This seemed [1101] BOHR
BOHR [1101] to divorce the world of the atom from the ordinary world about us and it be came increasingly difficult to picture atomic structure in “common-sense” terms.
For instance, the electron couldn’t take on just any orbit. It could have an orbit only at fixed distances from the nu cleus and each orbit had a certain fixed amount of energy. As it changed from one orbit to another, then, the amount of energy liberated or absorbed was fixed; and this amount consisted of whole quanta. In this way Planck’s quantum theory was interpreted as a manifestation of the discontinuous electron positions within an atom. Bohr was even able to choose orbital energies in such a way as to account for the lines in the hydrogen spectrum, showing that each one marked the ab sorption of quanta of energy just large enough to lift the electron from one par ticular orbit to another farther from the nucleus. (Or to mark the emission of a quantum of energy just large enough to drop the electron from one particular orbit to another nearer the nucleus.) In particular the regularities of the hydro gen spectrum, first noted by Balmer, were easily accounted for. To describe the discrete energies which electrons might possess, Bohr made use of Planck’s constant divided by 2n. This is symbolized as h and referred to as “h bar.” Bohr’s model of the hydrogen atom proved to be insufficiently complex to ac count for the fine detail of the spectral lines, however. He had postulated only circular orbits, but Sommerfeld [976] went on to work out the implications of the existence of elliptical orbits as well. Then orbits at various angles were also included. Regardless of the modifications neces sary Bohr’s scheme was the first reason ably successful attempt to make the inter nal structure of the atom explain spec troscopy and to use spectroscopic data to explain the internal structure of the atom. Not all the older generation was enthusiastic. Rayleigh [760], Zeeman [945], and Thomson were dubious but Jeans [1053], to Bohr’s everlasting grati tude, was firmly on his side. It was Thomson’s opposition to the new atom that sparked Bohr’s shift to Rutherford, by the way. Of course, Bohr won out smashingly in the end. For his new theory, he re ceived the 1922 Nobel Prize in physics. The theory received experimental sup port from the work of Franck [1081] and G. Hertz [1116], who in their turn were awarded Nobel Prizes. Bohr was unable to work out satis factory models for atoms more complex than hydrogen, but he was among those who pointed out that where more than one electron existed in the atom, they must exist in “shells”; and he pointed out that it was the electron content of the outermost shell that determined the chemical properties of the atoms of a particular element. Pauli [1228] brought this notion to fulfillment. The picture of the electron as both a particle (as in his own theory) and a wave (in Schrodinger’s) induced Bohr in 1927 to put forth what has been called the principle of complementarity—that a phenomenon can be looked upon in each of two mutually exclusive ways, with both outlooks nevertheless remaining valid in their own terms. This principle has been eagerly adopted by some con temporary biologists and used as a vehi cle for a new kind of vitalism. The sug gestion is made that living systems can be interpreted, on the one hand, accord ing to physical and chemical laws gov erning the components of a cell and, on the other, according to vitalistic laws, governing the cell or organism as a whole. According to this view there would be elements of life forever un amenable to ordinary investigation by the physical sciences. It seems doubtful, though, that this new variety of vitalism will be any more successful in the long run than the other varieties strewn in the boneyards of history. In Copenhagen, during the 1920s and 1930s, Bohr headed an institute for atomic studies that was supported by the Carlsberg brewery (the greatest service offered by beer to theoretical physics since the time of Joule [613]). It proved a magnet for theoretical physicists from
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