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531 [824] FRASCH
DEMARÇAY [825] creatures had instead a flexible rod run ning down their backs, at least in their larval stage if not in their adulthood, and vertebrates showed this same rod (a no tochord) in the embryonic portion of their life. Kovalevski [750] was making similar observations. In 1880 Balfour suggested that all creatures possessing a notochord at some time in their life be grouped in a phylum, Chordata, and that suggestion was accepted. The Vertebrata are a sub phylum within Chordata, making up al most all of it, to be sure. Shortly afterward, Balfour suffered an attack of typhoid fever and in 1882 went to Switzerland in the hope that mountain air would restore his health. He at tempted to climb one of the as-yet-un- conquered crags of Mont Blanc and never returned. He was only thirty years old. [824] FRASCH, Herman (frahsh) German-American chemist Born: Gaildorf, Württemberg, December 25, 1851 Died: Paris, France, May 1, 1914 Frasch’s father was mayor of the town in which young Frasch was bom and he could undoubtedly have received the best chemical education in the world in Ger many. However, he was one of many who felt the call of the land beyond the Atlantic and in 1868 he arrived in the United States during its post-Civil War prosperity and established a laboratory in Philadelphia. Not many years before, the first oil well had been drilled in Pennsylvania and Frasch was astute enough to get into the field, specializing in petroleum chemistry. One of the problems of the infant oil industry was the fact that much of the oil was “sour” and unsalable because it contained sulfur compounds and stank to high heaven even after refining. It was Frasch in 1887 who patented a method for removing the sulfur compounds through the use of metallic oxides. The supply of usable petroleum was multi plied and the industry was ready for the coming of the automobile. Frasch’s attention turned to sulfur, the valuable mineral out of which sulfuric acid, industry’s most vital chemical, was manufactured. The island of Sicily held virtually a world monopoly on sulfur; the sulfur deposits were near the surface of the earth and Sicilian labor was cheap and mercilessly exploited. There were notable deposits of sulfur in Louisiana and Texas, but they were deeper under ground, and American labor was com paratively dear and accustomed to bet- ter-than-Sicilian treatment. Frasch adapted his petroleum experi ence to the problem. Why not pump sul fur as one pumps petroleum? To be sure, sulfur is a solid and not a liquid and not even boiling water is hot enough to melt it. But what if superheated water under pressure were sent down? The sulfur would melt and could be forced up to the surface. In 1894 Frasch had weighed all the factors as far as they could be weighed on paper and decided to gamble with an actual attempt in the field, down in the swamps of Louisiana. He was a cracker jack chemical engineer and he managed to solve each problem that arose (and there were many). Even when he made it work, there was still a problem in the matter of fuel to supply the hot water. If the fuel had to be transported over too great a distance, it would be expensive, and the sulfur would be expensive also— too expensive. Fortunately the famous Texas oil wells began to come in about then and fuel oil was cheap. By 1902 the Frasch process was prac tical from end to end. America had a homegrown and, for the foreseeable fu ture, inexhaustible supply of sulfur (and therefore of sulfuric acid). Imports from Sicily ceased and one more step was taken toward America’s chemical inde pendence of Europe, a process that was to reach a climax following World War I, which began three months after Frasch’s death. [825] DEMARÇAY, Eugène Anatole (duh-mahr-say') French chemist Born: Paris, January 1, 1852 Died: Paris, 1904 5 3 2
[826] LINDE MANN RAMON Y CAJAL
Demargay first worked in organic chemistry with Dumas [514] among his teachers. During an investigation of com pounds of nitrogen and sulfur, an explo sion destroyed the sight in one eye, an accident much like that suffered by Bun sen [565] some forty years earlier. Demargay went on to the study of spectra and grew to be one of the fore most experts in the field, learning with his one eye to read the complicated line patterns like a book. In 1896 he began the research that led to the discovery of a new rare-earth element, europium. In 1898, when Madame Curie [965] believed she had isolated a new element (radium), judging by its radioactive properties, she called in Demargay. He found prominent lines of barium in the sample handed him (barium is very like radium in its chemical properties, and any process intended to separate the one will also separate the other) but in among them were the lines of a new ele ment. The presence of radium was con firmed. [826] LINDEMANN, Carl Louis Ferdinand von (lin'-duh-mahn) German mathematician Born: Hannover, April 12, 1852 Died: Munich, March 6, 1939 Lindemann received his Ph.D. at Er langen under Klein [800] in 1873. Mak ing use of Hermite’s [641] methods, he tackled that well-known quantity, ir (pi), the ratio of the circumference of a circle to its diameter and showed, in 1882, that it was a transcendental number. This was of particular importance because it was possible to show that no line equivalent in length to a transcendental number could be constructed in a finite number of steps by use of a straight-edge and compass alone. It was by the use of these (the proper tools of the geometer, according to Plato [24]) that, for two thousand years, math ematicians had been trying to construct a square equal in area to a given circle (“squaring the circle”). Since ir was transcendental and since any method of squaring a circle had to construct a line equivalent to ir, Lindemann had finally shown once and for all that squaring the circle by Platonic methods was impossi ble, though by other methods it was not. (Nevertheless, the circle-squarers have not given up and will always be with us.) Lindemann had less luck with another famous mathematical problem. He spent six years or more attempting to prove Fermat’s [188] last theorem and in 1907 published a very long paper in which he thought he had succeeded; but it con tained a blatant error at the very begin ning, one he had somehow overlooked. He joined the faculty of the University of Königsberg in 1883 and the Univer sity of Munich in 1893, retiring in 1923. [827] RAMON Y CAJAL, Santiago (rah-mone' ee kah-hahl') Spanish histologist
1852
Died: Madrid, October 18, 1934 Ramon y Cajal, like Golgi [764], had a father in the medical profession, but Ramon’s own schooling was less aimed in the family direction. He seemed back ward in school and it was only after suc cessive apprenticeships to a barber and to a shoemaker that he finally got the chance to study medicine. After obtaining his degree in 1873 and serving a year in Cuba, he became pro fessor of anatomy at the University of Zaragoza in 1877. He was hampered for a time by serious illnesses—malaria while he served in Cuba (a Spanish possession at the time), tuberculosis at home in Spain. In the 1880s he learned of Golgi’s stain, improved upon it, and went to work on the nervous system. By 1889 he had worked out the connections of the cells in the gray matter of the brain and spinal cord and had demonstrated the extreme complexity of the system. He also worked out the structure of the ret ina of the eye. He established the neuron theory, which proclaimed the nervous system to consist entirely of nerve cells and their processes, in contradistinction to Golgi, who opposed it. 533 [828] LÖFFLER
VAN’T HOFF [829] In 1889, at a scientific meeting in Ger many, Ramon y Cajal demonstrated his improved Golgi stain and won the sup port of Kolliker [600] and Waldeyer [722]. He shared the Nobel Prize in medicine and physiology with Golgi in 1906. He retired in 1922. [828] L6FFLER, Friedrich August Johannes (lerf'ler) German bacteriologist
Prussia, June 24, 1852 Died: Berlin, April 9, 1915 Loffler, the son of an army surgeon, obtained his M.D. from the University of Berlin in 1874. He worked for Koch [767] from 1879 to 1884 and applied Koch’s methods to the isolation of specific bacteria. His most important discovery, in 1884, was that of the bacillus of diphtheria. He showed that natural immunity to diph theria existed among some annimals and this laid the groundwork for Behring’s [846] labors in preparing an antitoxin. He also showed in 1898 that hoof-and- mouth disease was caused by a virus, the first animal disease pinned to such a cause. [829] VAN’T HOFF, Jacobus Henricus (vahnt hof) Dutch physical chemist Born: Rotterdam, August 30, 1852
Died: Steglitz (part of Berlin), Germany, March 1, 1911 Van’t Hoff, the son of a physician, de cided on a chemical career against the wishes of his parents. He had his way and after attending college in the Neth erlands (where Beijerinck [817] was a friend) he traveled to Bonn, Germany, in 1872 to study under Kekule [680], who paid him little attention. After that he spent some time in Paris before re turning to the Netherlands. However, he did not wait to complete his education to begin his career. In 1874, at the age of twenty-two, and with his Ph.D. from the University of Utrecht as yet a few months in the future, he published a startling paper on the struc ture of organic compounds. Chemists had been puzzling for more than half a century over the fact that some organic compounds were optically active while others were not. As long ago as Biot [404] there had been the suggestion that this was due to some sort of asymmetry, but the nature and location of the asym metry remained a mystery. Pasteur [642] had located the asymmetry in crystals, but that did not help with respect to the optical activity of substances in solution. Van’t Hoff suggested that the asym metry existed in the molecules them selves. He drew the four valences of the carbon atom (each represented as a short line or “bond”), not two-dimen sionally toward the four angles of a square, as Couper [686] had done, but three-dimensionally toward the four an gles of a tetrahedron. When the tetrahe dral arrangement was considered, mat ters cleared up. If four different types of groupings were attached to the four car bon bonds, an asymmetric situation re sulted and two compounds, mirror im ages of each other, could be shown to exist. It was just these asymmetric com pounds that showed optical activity (ro tating the plane of polarized light); others did not. A similar theory was put forth simultaneously by another young ster, Le Bel [787], and the two share the credit.
The theory of the spatial distribution of the carbon bonds was bitterly at tacked by some of the more conservative chemists such as Kolbe [610] who thought that atoms and bonds were just convenient fictions and that giving actual directions to carbon bonds was to take them far too literally. Helmholtz [631] also was suspicious of the wild growth in the popularity of the structural formula. However Van’t Hoff’s theory explained so much that it was eventually accepted in full and for over half a century served as an adequate guide to structural theory in organic chemistry. To be sure, a more sophisticated view of chemical bonds arose with the work of men such as Pauling [1236] in the 1930s, but the 534 [829] van
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h o f f HALSTED
[830] Van’t Hoff theory is still the easiest way to explain optical activity to students. Van’t Hoffs reputation did not suffer unduly from Kolbe’s blast, for only a few months afterward he was offered a position as professor of chemistry, min eralogy, and geology at Amsterdam Uni versity and started on his duties in 1878. He promptly turned from organic chem istry to the new field of physical chemis try being established by Ostwald [840]. He went to work on thermodynamics and in 1884 published the results of his researches. These consisted among other things of a good statement of the law of mass action and of considerable material on chemical thermodynamics. Here, however, he was unfortunate. Much of his work had (unknown to the French and German leaders in the field) been done a decade and more before by Gibbs [740], Guldberg [721], and Waage [701]. The primary credit went to them rather than to Van’t Hoff. Van’t Hoff continued working on chemical thermodynamics, however, and grew interested particularly in the prob lems of dilute solutions. In 1886 he showed that in some ways the simple laws that govern the behavior of gases could also be applied to the material that was sparsely dissolved in liquid solvents. It was as though the dissolved molecules moved around in the liquid as gas mole cules moved around in space. He devel oped these notions over the next decade and this led to a far better understanding of solutions than had been possible be fore, although here again he was at tacked rather violently, this time by Lothar Meyer [685]. And again the at tack did not harm him. In 1893 he received the Davy medal of the Royal Society. When the Nobel Prizes were established in 1901, the first to receive the award in chemistry was Van’t Hoff, for his work on solutions. In 1896 he transferred his labors from Amsterdam to Berlin, and his last years were spent in studies on the behavior of the mixture of salts found in the Stass- furt deposits, the results of which were important to Germany’s chemical indus tries. [830] HALSTED, William Stewart American surgeon Born: New York, New York, September 23, 1852 Died: Baltimore, Maryland, Sep tember 7, 1922 Halsted, the son of a prosperous mer chant, was privately tutored at first and was then sent to a religious school from which he ran away. Finally, he found stability at Phillips Exeter at Andover, Massachusetts. He graduated from Yale in 1874, where he was primarily inter ested in sports (serving as captain of the football team, for instance). It was not till his senior year that he became inter ested in medicine. He bent his ambition toward medical school and obtained his M.D. at Columbia in 1877. He went on to spend a year in Europe, where he studied under Kolliker [600] among others. He was the first professor of surgery at Johns Hopkins University, joining the faculty in 1886. There he es tablished the first separate surgical school in the United States. He was one of the first to make use of cocaine injections for local anesthesia following the pioneer work of Freud [865] and Roller [882], In his work with cocaine, he experimented on himself to determine safety of use and became ad dicted (the dangers of such drug addic tion were not yet understood) and it was only with difficulty, and several opera tions, that he freed himself of the in cubus. Halsted continued the work of Lister [672] and even went beyond it. In 1890 he became the first surgeon of impor tance to use rubber gloves dining opera tions. He used them first to protect a nurse against contact dermatitis and then, in June 1890, married her. The use of rubber gloves was a valuable innova tion, since rubber can be sterilized more drastically and effectively than the skin of the hands. This marked the transition from antiseptic surgery (killing the germs that are present) to aseptic sur gery (not letting the germs get there in the first place). Halsted was particularly noted for the skill of his breast amputa tions.
535 [831] MOISSAN
MOISSAN [831] His meticulousness persisted outside the operating room: He sent his shirts to Paris to have them laundered. [831] MOISSAN, Ferdinand Frédéric Henri (mwah-sahn') French chemist
Moissan was the son of a railway em ployee. His early schooling was ham pered by poverty and at the age of eigh teen he was apprenticed to an apothe cary. His interest in chemistry was great enough, however, for him to break away two years later and obtain by hard labor the education he believed he needed. In 1879 he qualified as a professional phar macist and in 1882 he married a loving and charming wife who, by good for tune, had a sympathetic father (also a pharmacist) who was willing to help sup port Moissan while he devoted himself to chemistry and finally earned his Ph.D. in 1885. He then joined the faculty of the School of Pharmacy in Paris in 1886 and, in 1900, moved on to the Sorbonne. Moissan’s chemistry teacher, Edmond Frémy [582], back in the 1870s had been interested in isolating the element fluorine. Since the days of Davy [421], chemists had realized this element existed and must be similar in properties to chlorine but even more active. Nu merous chemists had tried to isolate the gas. Davy himself had tried; so had Gay- Lussac [420] and Thénard [416], All had failed and most, including Davy, suffered badly from poisoning by fluorine or its compounds; some chemists died. The trouble was that even if fluorine gas could be broken loose from its com pounds, it proceeded to combine with al most anything in sight. Moissan decided to undertake this dangerous task and he, too, suffered the consequences of exposure to the com pounds of this violent element. He was only fifty-four when he died and in mid dle age he dolefully stated a number of times that he believed fluorine had short ened his life by ten years. In his attempt to isolate fluorine he used platinum, one of the few materials that were reasonably immune to the on slaughts of fluorine, for his apparatus. He tried numerous variations of tech nique and on June 26, 1886, passed an electric current through a solution of potassium fluoride in hydrofluoric acid in all-platinum equipment. He chilled the solution to — 50°C to reduce the activ ity of fluorine. He isolated a gas in these platinum surroundings, a pale yellow gas that bit savagely at anything but plati num that was brought near it. It was the long-sought fluorine, the most active of all the elements. Shortly after this dramatic discovery Moissan was appointed professor of pharmacy at the School of Pharmacy and in 1900 received a professorial ap pointment in the University of Paris, where his lectures were superb. The cli mactic reward, however, was the Nobel Prize in chemistry, which was awarded him in 1906 for his isolation of fluorine. He won this award, according to report, by only one vote over Mendeléev [705] who, it might well be argued, deserved it more. Moissan’s discovery of fluorine and his invention of an electric furnace by means of which many uncommon ele ments could be prepared in unprece dented purity, were by no means his most dramatic achievements or the ones for which he is best known. That honor belongs to what most people now con sider a fake (though not Moissan’s). He grew interested in trying to prepare carbon in its most beautiful and valuable form, that of diamond. At first he tried to get diamonds from compounds of car bon and his beloved fluorine. When that didn’t work, he involved himself in un pleasant, long-drawn-out experiments in which he tried to convert charcoal into diamond by the use of high pressures. We now know that with the pressures and temperatures available to Moissan it was impossible to produce diamonds. The deed was not accomplished for a half century and had to await the equip ment devised by Bridgman [1080] for at taining new levels of pressure. In 1893, nevertheless, it seemed to Moissan he had succeeded. Several tiny Download 17.33 Mb. Do'stlaringiz bilan baham: 
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