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[893] BOSE ARRHENIUS [894]
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[893] BOSE
ARRHENIUS [894] [893] BOSE, Sir Jagadischandra (bose) Indian physicist
Nasirabad, Bangladesh), November 30, 1858
November 23, 1937 Bose, the first Indian scientist to gain an international reputation, was the son of a civil servant. He studied at St. Xavier’s School in Calcutta, graduating in 1879. He then went to England, in tending to gain a medical education, but switched to science instead. He attended Cambridge, where Rayleigh [760] was one of his teachers. He returned to India in 1884 and gained a professorial posi tion at Calcutta in 1887. The Bose Re search Institute was founded in Calcutta in 1917. Bose presided over the dedica tion and served as director till his death. He was knighted in 1917. Bose was best known for his careful studies of plant growth. He devised very sensitive instruments capable of record ing extremely small movements. These were capable of magnifying plant growth ten million times. Bose was thus able to follow plant responses to a variety of stimuli. [894] ARRHENIUS, Svante August (ar-ray'nee-us) Swedish chemist Born: Vik (near Uppsala), February 19, 1859 Died: Stockholm, October 2, 1927
Arrhenius, the son of a surveyor, was an infant prodigy (he taught himself to read at three) and a brilliant student, graduating from high school as the youngest and brightest in his class. While attending the University of Uppsala he began to study how electricity passed through solutions, an important subject since the days of Davy [421] nearly a century earlier. Faraday [474] had worked out the laws of electrolysis and from those laws it seemed that electricity, like matter, must exist in the form of tiny particles. Faraday had spoken of “ions” (from a Greek word for “wanderer”), these being the particles that carried electricity through the solution, but there remained the question as to just what the ions were. Men like Williamson [650] and Clausius [633] had suggested they might be atoms or groups of atoms, but they did not proceed to make the necessary points that would explain matters. Ar rhenius did. He considered the fact that some sub stances, such as salt (sodium chloride), conducted electricity when in solution and were “electrolytes,” while others, such as sugar (sucrose), did not and were “non-electrolytes.” Other differ ences between electrolytes and non electrolytes arose in connection with the freezing point of water. A substance dissolved in water low ered the water’s freezing point some what. This lowering was in proportion to the quantity of substance dissolved, as had been shown by the work of Raoult [684]. Doubling the quantity doubled the lowering. For different substances in solution, the lowering was in inverse proportion to the molecular weight. Thus, ordinary sugar (sucrose) had a molecular weight about twice that of grape sugar (glu cose). A gram of glucose dissolved in a liter of water lowered the freezing point twice as much as a gram of sucrose so dissolved. Since the glucose molecule was only half the size of the sucrose molecule, a gram of glucose would con tain twice as many molecules as a gram of sucrose. It was easy to show, then, that the amount of lowering of the freez ing point was proportional to the number of particles present in solution, whatever the dissolved substance. This held, at least, for non-electrolytes. What about electrolytes? A fixed quantity of sodium chloride is composed of a fixed number of molecules. From this the amount of lowering of the freez ing point could be calculated. However, as it turned out, the amount of lowering induced by dissolved sodium chloride was just twice what it ought to be. One explanation for this was that each mole cule of sodium chloride gave rise to two particles. This was also true of other 577 [894] ARRHENIUS ARRHENIUS
electrolytes—potassium bromide, for in stance, or sodium nitrate. On the other hand, a substance like barium chloride or sodium sulfate pro duced three times the lowering that one might expect. Each molecule must give rise to three particles. This anomalous behavior of electro lytes held for other properties that de pended upon the number of particles present, as, for instance, the osmotic pressure; that is, the pressure forcing liquid through a semipermeable mem brane of the type Graham [547] used in separating crystalloids from colloids. Arrhenius decided that the only expla nation was that sodium chloride did break up into two particles, a sodium and a chlorine, as soon as it was placed in solution. Of course, these solutions did not contain metallic sodium and gaseous chlorine; so what happened must be that the sodium and chlorine carried electric charges, and that was why sodium chloride solutions could transmit an elec tric current. The positively charged sodium ion and the negatively charged chloride ion would have properties quite different from the uncharged atoms. In the same way, barium chloride would split into three particles, a doubly charged positive barium ion and two singly charged nega tive chloride ions. This turned out to be a revolutionary concept; a bit too revolutionary for most of the chemists of the time. Electrically charged atoms were inconceivable to those who accepted the century-old view of Dalton [389] that atoms were struc tureless and indivisible. Where would the electric charge come from? And how could a stable substance like sodium chloride break up at once as a result of solution in so mild a substance as water? One of Arrhenius’ teachers, Cleve [746], dismissed the young man peremptorily when the latter tried to explain his theory.
Finally, in 1884 Arrhenius prepared his theory of ionic dissociation as part of his Ph.D. dissertation. He underwent a rigorous four-hour examination and was then awarded the lowest possible passing grade by his incredulous examiners. Fortunately it was a day when a new kind of physical chemistry was on the rise. The two brightest stars of the new discipline, Van’t Hoff [829] and Ostwald [840], were intrigued by the new theory as were Clausius [633] and J. L. Meyer [685]. They took up the cudgels on its behalf against such powerful opponents as Mendeleev [705], Ostwald even trav eled to Uppsala just to discuss the matter with the young man. Arrhenius worked with the two in Germany (also with Boltzmann [769]) and for a decade they formed a loud minority view in the world of chemistry. In 1889 Arrhenius contributed to the new physical chemis try again by studying how rates of reac tion increased with temperature. He suggested the existence of an energy of activation, an amount of energy that must be supplied molecules before they will react. This is a concept that is essen tial to the theory of catalysis. Arrhenius’ stock began to go up sud denly in the 1890s, when J. J. Thomson [869] discovered the electron and Bec querel [834] discovered radioactivity. The atom was not structureless after all, it appeared, but was made up of electri cally charged particles, notably the nega tively charged electron. A negative ion such as a chloride ion could now easily be seen to be a chlorine atom that had obtained one electron more than its fair share, while a positive sodium ion was a sodium atom with an electron missing. If the sodium and chlorine in a sodium chloride molecule were held together by the attraction of electric charges, the somewhat insulating properties of water could make the atoms fall apart, so to speak. If, in doing so, they divided the electrons unequally, a positively charged ion and a negatively charged ion would be formed. Suddenly Arrhenius’ ionic theory made the very best kind of sense. He re turned to Sweden from Germany in 1891 and in 1895 he was appointed to a professorship at the University of Stock holm. In 1903, for the same thesis that had barely earned him a passing grade in his doctor’s examination, he won the Nobel Prize in chemistry. This took place only after considerable
[894] ARRHENIUS POPOV
discussion within the group awarding the prize as to whether it should be recorded as the prize in chemistry or in physics; some even suggested giving Arrhenius a half share in both prizes. Cleve, who had turned a deaf ear to Arrhenius a score of years earlier, now explained that it was this “in-betweenness” of the work that had obscured its importance to him, and he made up for this by earnestly sup porting Arrhenius for the award. Arrhenius then turned to the large mysteries of science. He studied the ap plication of physical chemistry to the life processes and was one of the forerunners of modem molecular biology. In a book entitled Worlds in the Making, published in 1908, he upheld the notion of the universality of life and suggested that life on earth had begun when living spores had reached it across the emptiness of space. He pointed out that spores could withstand the cold and airlessness of space for indefinite periods and he believed that the driving force that car ried spores from star to star was the pressure of radiation, a pressure that had recently been measured by Lebedev [952],
The consequence of this theory, he believed, was that life was diffused throughout the universe wherever it could exist at all, a view which has recently been revived in modified form by Crick [1406]. He was particularly interested in the possibility of life on Mars, a point made popular at the time by the work of Schiaparelli [714] and Lowell [860], Unfortunately, two points, one experi mental and one philosophical, militate against the Arrhenius theory of space wandering spores. The first is that al though spores are resistant to cold and vacuum they are not resistant to ultravi olet light and other energetic radiation. Since space (at least in the neighborhood of stars) is riddled with such energetic radiation, the survival of spores is very questionable. The second objection is that a spore theory does not really explain the origin of life; it merely puts it off. If life did not originate on the earth but on another world and reached us only in the form of already living spores, how did the life originate in the first place on the other world? It took another generation and the work of Urey [1164] and others be fore scientists believed they could begin to speculate reasonably on the subject of extraterrestrial life. In his book Arrhenius also argued against the “heat death” of the universe, the ultimate state of maximum entropy envisaged by Clausius. Arrhenius be lieved processes existed that would de crease entropy and maintain equilibrium. In this he was a kind of forerunner of those like Gold [1437] who imagined a universe undergoing continuous creation. Arrhenius also pointed out that carbon dioxide in the atmosphere served as a “heat trap,” for it allowed the high- frequency sunlight to penetrate freely to the earth’s surface but was opaque to the low-frequency infrared radiation which the earth reradiated at night. A slight rise in carbon dioxide content in the at mosphere would raise the earth’s temper ature markedly and might account for the worldwide mildness in the dinosaur- ridden Mesozoic Era. A slight fall in car bon dioxide content might, in turn, set off an Ice Age. Such a suggestion is still taken seriously and, indeed, may account for the situation on the planet Venus, where the atmosphere was found, by W. S. Adams [1045] a generation later, to be high in carbon dioxide, and where Mariner II, the Venus probe, demon strated in 1962 that the surface tempera ture of Venus was about 350°C, far higher than would be expected without a carbon-dioxide “greenhouse effect.” In 1905 after turning down (for the second time) the offer of a professorship in Germany, Arrhenius was appointed director of the Nobel Institute for Physi cal Chemistry and held that post until shortly before his death. [895] POPOV, Alexander Stepanovich Russian physicist
March 16, 1859 Died: St. Petersburg, January 13, 1906 Popov, the son of a priest, had plans for the priesthood himself but switched 579 [896] LOEB
CURIE [897] to mathematics. He graduated from the University of St. Petersburg in 1883 and eventually joined its faculty. Like Marconi [1025] he recognized the importance of H. R. Hertz’s [873] dis covery of radio waves and began to work on methods of receiving them over long distances the year before Marconi did. He was the first to use an antenna and in 1897 could send a signal from ship to shore for three miles. In the years following, Popov man aged to persuade the Russian navy to begin the installation of radio equipment in its vessels. However, Popov was mainly interested in using his receiver for signals from lightning strokes, in his studies of the physics of thunderstorms, and it was Marconi who took the crucial step of commercializing the radio signal, and the dramatic one of sending it across the ocean. The Soviet Union, in a fit of nation alist fervor, insists that it was Popov who invented the radio. Though the Soviet Union has a poor case, it is not quite as poor as the nationalist fervor of nations opposed to the Soviet Union makes it out to be. [896] LOEB, Jacques German-American physiologist Born: Mayen, Rhenish Prussia, April 7, 1859 Died: Hamilton, Bermuda, February 11, 1924 Loeb, the son of a prosperous Jewish businessman, obtained his M.D. at Stras bourg in 1884 and taught first at Stras bourg and then at Wurzburg. After mar rying an American philologist, he emi grated to the United States. He arrived in 1891 and joined the faculty of the University of Chicago. In 1902 he trans ferred to the University of California and in 1910 joined the staff of the Rockefeller Institute for Medical Re search (now Rockefeller University) in New York. Leob was a mechanist at the time when mechanism was reaching new heights, thanks to the work of Sherring ton [881] and Pavlov [802] on reflexes. Loeb tried to show that the tropisms that govern plant behavior (simple reactions toward or away from light, water, grav ity, and so on) might be applied to sim ple animals and that, indeed, it was pos sible to elaborate such behavior into quite complicated structures. He even suggested that man’s morals and ethics were but the products of tropism combi nations. In 1899 he attracted wide attention when he found that an unfertilized sea urchin egg could be made to develop to maturity by proper environmental changes. Such “artificial parthenogen esis” was later extended to frogs. Un doubtedly, part of the interest in this work among laymen was founded on the grisly (but unjustified) thought that the male sex might turn out to be superfluous. [897] CURIE, Pierre French chemist Born: Paris, May 15, 1859 Died: Paris, April 19, 1906 Pierre, the son of a physician, was a slow learner as a child and received his early schooling at home. Then he studied at the Sorbonne where he gained his bachelor’s degree in 1875 and his master’s in 1877. From 1878 he was an assistant teacher in the physical labora tory there. In 1880 he and his brother observed how an electric potential appeared across crystals of quartz and of Rochelle salt when pressure was applied to them. The potential varied directly with the pres sure and the brothers named the phe nomenon piezoelectricity, from a Greek word meaning “to press.” Conversely, if a rapidly changing electric potential is applied to such a crystal, its faces can be made to vibrate rapidly. In this way the crystal can be used to set up beams of ultrasonic sound, sound waves with fre quencies far too high to hear. Crystals with piezoelectric properties form an es sential portion of sound-electronic de vices such as microphones and record players. For his doctorate, which he obtained 5 8 0
[898] REID
OSBORNE [900] in 1895, Pierre Curie studied the effect of heat on magnetism and showed that there is a certain critical temperature (still called the Curie point) above which magnetic properties disappear. In that same year he married Marie Sklo- dowska [965] and after that his scientific career merged with hers. Earlier in life he had said a wife was a hindrance to a scientist, but Marie was surely an excep tion.
He conducted one dangerous experi ment on his own. Becquerel [834] had noted a skin bum after carrying some ra dium in his pocket. Curie confirmed this in 1901 by deliberately inducing a bum on his arm. He also measured the heat given off by radium as 140 calories per gram per hour. This was the first indica tion of the huge energies available within the atom; energies that were to make themselves all too evident in nuclear bombs. Thus began an understanding of the dangers of radioactivity, dangers that hang dreadfully over mankind today. In 1904 he was appointed professor of physics at the Sorbonne, a post to which his wife succeeded when, two years later, his life was snuffed out in a street acci dent. [898] REID, Harry Fielding American geophysicist Born: Baltimore, Maryland, May 18, 1859 Died: Baltimore, Maryland, June 18, 1944 Reid, the first American geophysicist, was a great-grandnephew of George Washington on his mother’s side. He ob tained his Ph.D. at Johns Hopkins Uni versity in 1885, and after teaching at Case School of Applied Science (now Case Western Reserve University) and at the University of Chicago, he returned to Johns Hopkins as a professor of phys ics in 1894 and remained there until his retirement in 1930. His early interest was in glaciers and their movements and perhaps it was this that led him to consider the earth’s crust and its movements. He was part of the scientific committee chosen to investigate the San Francisco earthquake of 1906. His observations of the displacement of the crust that resulted from that disaster led him to propose the “elastic rebound theory.” This supposed that faults were preexisting and were not breaks in the cmst caused by earthquakes. Rather, pressures along the fault increased until there was a sudden slippage of one side of the fault against the other, the vibra tions causing the effects of the earth quake. This theory is still accepted today. [899] SMITH, Theobald American pathologist Born: Albany, New York, July 31, 1859
Died: New York, New York, December 10, 1934 Smith was the son of a tailor, who, to gether with his wife, were of German birth (the surname being, originally, Schmitt). He graduated from Cornell University in 1881 with honors, then at tended Albany Medical College, getting his M.D. in 1883 at the top of his class. In 1892 he demonstrated that Texas cattle fever was caused by a protozoan parasite that was spread by blood-suck ing ticks. This was the first definite indi cation of the spread of disease by blood sucking arthropods (ticks in this case, insects in others). It was met with con siderable skepticism but it laid the groundwork for the findings of Reed [822], Ricketts [992], and others. [900] OSBORNE, Thomas Burr American biochemist
August 5, 1859 Died: New Haven, January 29, 1929
Osborne, the son of a banker, gradu ated from Yale in 1881, made a half hearted attempt in the direction of a medical career, then went on to graduate work in chemistry. He obtained his Ph.D. in 1885 with a dissertation on in organic analysis but then took a position
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