Biographical encyclopedia
Download 17.33 Mb. Pdf ko'rish
|
|
626 [981] SPEMANN
SPEMANN [981] was to dominate his scientific life. He then returned to the United States and joined the newly formed Rockefeller In stitute (now Rockefeller University) in 1905.
Levene isolated the carbohydrate por tion of the nucleic acid molecule and identified it, a feat that had stumped even Kossel. In 1909 Levene showed that the five-carbon sugar, ribose, was to be found in some nucleic acids, and in 1929 he showed that a hitherto unknown sugar, deoxyribose (ribose minus one ox ygen atom), was to be found in others. To this day, no other sugars have been found in nucleic acids and, indeed, all nucleic acids are divided into two groups, ribonucleic acid and deoxy ribonucleic acid, depending on which sugar they contain. Under the abbrevi ations RNA and DNA these have be come almost the best-known letter com binations in biochemistry, especially after the vast breakthrough in nucleic acid chemistry a generation later with James Watson [1480] and Crick [1406]. Levene worked out the manner in which the components of the nucleic acids were combined into nucleotides (the building blocks of the large nucleic acid molecule) and how these were com bined into chains. This work was ex tended and elaborated later by Todd [1331], [981] SPEMANN, Hans (shpay'mahn) German zoologist Born: Stuttgart, Württemberg, June 27, 1869 Died: Freiburg-im-Breisgau, Baden, September 12, 1941 Although Spemann, the son of a book publisher, studied medicine, physics, and botany, as well as zoology (physics under Roentgen [639]), it was upon zo ology that he centered his professional life. He obtained his doctorate in that subject in 1895 at the University of Würzburg under Boveri [923]. From 1919 until his retirement in 1935, he was professor of zoology at the University of Freiburg. His outstanding work was done on embryos. One of the most puzzling ques tions in biology was just how an embryo developed. In the 1880s it had seemed as though the first act of a fertilized ovum, that of dividing in two, determined the plane of bilateral symmetry. If one of the resulting cells was killed with a hot needle, what was left developed into a longitudinal half of an embryo. It seemed that the fertilized ovum was or ganized within, into precursors of its eventual parts from the very start; even, there was reason to think, from before the moment of fertilization. This was al most a kind of revival of the early theory of preformation that Wolff [313] had laid to rest a century before. Further experiments showed that if the egg divisions were not killed, but sepa rated, then the individual cells after the first division, or even after the first five divisions, could each develop into a com plete (though smaller) embryo. This led to the suggestion that there was some vital force within the cell that directed it toward normal development even when it represented a part rather than the whole of the original fertilized egg. To Spemann, it seemed that the difference in behavior when a cell was killed but allowed to remain where it was, and when a cell was actually sepa rated, showed that the various cells of an embryo exerted an effect upon then- neighbors. In the 1920s he undertook a series of experiments. He demonstrated that even after an embryo had begun to show definite signs of differentiation, it could still be divided in half with each half producing a whole embryo, although one half was almost all “potential back” and the other almost all “potential belly.” This showed that the cells remained plas tic quite late in the game and once again knocked out the possibility of preforma tion. Furthermore, Spemann found that an area of an embryo develops according to the nature of the neighboring areas. An eyeball develops originally out of the brain material and is joined by a lens that develops out of the nearby skin. If the eyeball is placed near a distant section of the skin, one that would
[982] PREGL
POULSEN [983] never, in the course of nature, develop a lens, it nevertheless begins to develop one.
There were apparently “organizers” in the embryo (not a mysterious vital force, but definite chemicals) that brought about certain developments in their neighborhood. An area containing an organizer that brought about the de velopment of nerve tissue in a frog em bryo could even bring about the develop ment of nerve tissue in a newt embryo. By properly transplanting parts of em bryos, a portion on the way toward de velopment as brain will develop as intes tine. In Spemann’s time the hormone con cept advanced by Starling [954] and Bayliss [902] was well understood, as it was not in the time of his predecessors. It could be seen that embryonic develop ment was under hormonal control, and neither a vital force nor preformation had to be called upon. For his work Spemann was awarded the 1935 Nobel Prize in medicine and physiology. [982] PREGL, Fritz (pra/gul) Austrian chemist
Ljubljana, Yugoslavia), September 3, 1869
Pregl attended the University of Graz (in the town to which he and his mother had moved in 1887 after his father’s death) and obtained his medical degree in 1894. In 1904 he was appointed to a professorial position there after having done postgraduate work in physical chemistry under Ostwald [840] at Leip zig.
He practiced medicine, performing eye surgery, but his real interest lay in re search. In particular he investigated the bile acids, complicated compounds that one could isolate in small quantities from liver bile. He began his work from the medical standpoint but found himself slowly lured into chemistry. It was the smallness of the quantities of material he had to deal with that forced Pregl into the path of fame. In 1909 he found himself staring at a barely visible amount of a new com pound whose molecular structure he had to determine. There was not enough to analyze by usual methods, so he was faced with two alternatives. Either he had to start all over, working on a far larger scale, or he had to invent analytic methods for unprecedentedly small quan tities of substances. He chose the latter course and from then on became an analytical chemist. He obtained a balance that was ex tremely precise and worked with a glass blower to produce new and tiny pieces of equipment. He put his surgeon’s hands to work in delicate manipulations. By 1911 he was demonstrating methods of analysis for the different elements, ac curately, with only 7 to 13 milligrams of substance at hand. He drove this further downward and by 1913 could handle as little as 3 milligrams. (Since Pregl’s time, microchemists have learned how to work with organic samples of only a few tenths of a milligram in weight.) Pregl’s manipulations made him world-famous. Levene [980] brought his methods to the United States, and in 1923 Pregl was awarded the Nobel Prize for chemistry for his microchemical feats. [983] POULSEN, Valdemar (powl'sin) Danish inventor Born: Copenhagen, November 23, 1869
Died: Copenhagen, July 1942 Poulsen was the first to reduce to practice the notion of having sound con trol the imposition of a varying magnetic field on a length of wire. That varying magnetic field could then be used to reproduce the sound wave. The idea was a perfectly good one but there were bugs in the practical applica tion thereof that could not easily be ironed out. Poulsen, who patented his device in 1898, could not find the neces sary financial backing. His company failed, and it was not till after World War II that the invention was perfected and that tape and wire recording became useful and popular. 6 2 8
[984] ADLER
BORDET [986] [984] ADLER, Alfred Austrian psychiatrist
28, 1937 Adler obtained his M.D. at Vienna in 1895 and began his medical career as an ophthalmologist, but his interest shifted to mental disorders and in 1902 he was one of the first to gravitate toward Freud [865], joining a discussion group which became the first psychoanalytic society. He was also one of the first to secede, disagreeing with Freud’s tendency to base his theories on the sex impulse. By 1911 he had evolved his own theories, in which power, not sex, was the main spring of action. The child, being a small and powerless item in a world dominated by adults, was painfully conscious of in feriority (Adler popularized the term “inferiority complex”) and the rest of his life was spent in an effort to attain “compensation.” Adler even viewed sex as primarily an attempt by each of two people to gain power over the other. Sex ual abnormality was not the cause of mental disturbance, in his view, but the consequence of it. His version of psychi atric treatment was much briefer than Freud’s psychoanalysis and dealt more actively with the patient’s overt difficul ties.
In 1919 he founded the first child guidance clinics in the Vienna school system. They were closed in 1934 by the reactionary regime of Engelbert Doll- fuss. After 1925 Adler visited the United States frequently. He proved a popular lecturer there and by 1935 decided to settle permanently in the United States. He died while on a lecture tour in Scot land. [985] HONDA, Kotaro Japanese metallurgist Born: Aichi-ken Prefecture, Feb ruary 1870 Died: Tokyo, February 12, 1954 Honda, the son of a farmer, was one of the Japanese scientists who seemed to burst on the world after Japan’s indus trialization in the late nineteenth cen tury. He was educated at Tokyo Imperial University. Between 1907 and 1911 he did graduate work in Germany and then returned at Tohoku University, becom ing its president in 1931. In 1916 he found that the addition of cobalt to tungsten steel produced an alloy capable of forming a more power ful magnet than ordinary steel. This opened the way to the new mag netic alloys and eventually thanks to fur ther research by Japanese metallurgists, led to the production of alnico, not only more strongly magnetic, but corrosion- resistant, relatively immune to vibration and temperature change, and cheaper than ordinary steel magnets. Nothing more advanced in the field of magnetism was produced until the mid-twentieth century, with the construction of elec tromagnets working at liquid helium temperatures and wound with super-con ducting wires. In 1937 Honda was awarded the Cul tural Order of the Rising Sun, the Japa nese equivalent of the Nobel Prize. [986] BORDET, Jules Jean Baptiste Vin cent (bawr-dayO Belgian bacteriologist Born: Soignies, Hainaut, June 13, 1870
Died: Brussels, April 6, 1961 Bordet obtained his medical degree in 1892 from the University of Brussels and then went on to the Pasteur Institute in Paris, where he worked under Mech- nikov [775]. In 1901 he founded the Pas teur Institute in Brussels and served as its director, thus, in effect, going into business for himself. In 1898 during his stay in Paris, Bor det discovered that if serum is heated to 55°C, the antibodies within it may not be destroyed (as is shown by the fact that the serum will still react with an tigens) but its ability to destroy bacteria is gone. Presumably some very fragile component or group of components of the serum must act as a complement for the antibody and make it possible for it
[987] BOLTWOOD
IVANOV [988] to react with the bacteria. Bordet called this component alexin, but Ehrlich [845] named it “complement” and it is so known today. In 1901 Bordet showed that when an antibody reacts with an antigen, comple ment is used up, a process called com plement fixation, and this has proved of importance in immunological work. In fact, Wasserman [951] devised his well- known diagnostic test for syphilis on the basis of complement fixation. Bordet went on, in 1906, to discover the bacillus of whooping cough and to devise a method of immunization against that disease. In 1907 he was appointed professor of bacteriology at the Univer sity of Brussels and, as a climax to his work on immunology, and with particu lar reference to his work on complement fixation, he received the 1919 Nobel Prize in medicine and physiology. In 1920 he wrote a treatise on immunology that admirably summarized the knowl edge of the time. He held out, however, against the cur rent of gathering knowledge concerning viruses, refusing to consider that the bac teriophages, discovered by Twort [1055], were actually organisms and long main taining they were merely toxins. [987] BOLTWOOD, Bertram Borden American chemist and physicist Born: Amherst, Massachusetts, July 27, 1870 Died: Hancock Point, Maine, August 15, 1927 Boltwood, the son of a lawyer, earned his doctor’s degree at Yale in 1897 and spent most of his later life on the faculty of that university. He turned to the study of radioactivity and in 1904 confirmed something that had been suspected by Ernest Ruther ford [996] (with whom Boltwood was to spend a year in 1909) and demon strated in one particular, at least, by Dorn [795]; that is, the point that the ra dioactive elements were not independent, but that one might be descended from another to form a radioactive series. In particular, radium was descended from uranium, and Boltwood discovered an el ement between, which he called ionium. Ionium turned out eventually to be a va riety of thorium and not a truly new ele ment. Boltwood, among others, was on the track of such atomic varieties, a con cept finally nailed down by Soddy [1052], In 1905 Boltwood carried through his radioactive series notion by pointing out that lead was always found in uranium minerals and might be the final stable product of uranium disintegration. In 1907 he was the first to suggest that, from the quantity of lead in uranium ores and from the known rate of ura nium disintegration, it might be possible to determine the age of the earth’s crust. Such radioactive dating did indeed prove possible eventually, and for the first time geologists did not need tortuous and un certain reasoning to date the geologic eras. Uranium decay is so slow that it is useless for periods within the era of man’s existence on the planet. For this, nonradioactive methods were developed, notably by Douglass [963], but eventu ally Libby [1342] put radioactivity, in the form of carbon-14, to use here as well. In 1927, due to the strain of over work, Boltwood suffered a nervous breakdown and, in a fit of depression, committed suicide. [988] IVANOV, Ilya Ivanovich (ee- vah'nuf) Russian biologist Born: Shigry, Kursk province, August 1, 1870 Died: Alma-Ata, Kazakh SSR, March 20, 1932 Ivanov, the son of a government clerk, studied at the universities of Moscow and of Kharkov, and did some post graduate work at the Pasteur Institute in Paris. His chief interest was reproductive bi ology and, in particular, the artificial in semination of domestic animals, a prac tice that had been pioneered by Spallan zani [302], Spallanzani merely showed that it was possible. Ivanov made of it a practical procedure. 6 3 0
[989] CLAUDE
PERRIN [990] As early as 1901 he founded the world’s first center for the artificial in semination of horses. Between 1908 and 1917 about eight thousand Russian mares were artificially inseminated, thus making it possible to use the most vigor ous stallions for multiple inseminations. After the October Revolution, the practice (encouraged by Soviet authori ties) was accelerated. By 1932 over 180.000 mares, 385,000 cows, and 1.615.000 ewes had been artificially in seminated and, of course, the practice spread beyond the Soviet boundaries, too.
[989] CLAUDE, Georges French chemist Bom: Paris, September 24, 1870 Died: Saint-Cloud, Seine-et-Oise, May 23, 1960 Claude was particularly interested in liquefying gases. Independently of Linde [625] he devised a method of producing liquid air in quantity in 1902. Earlier, in 1897, he had found that acetylene (which is very inflammable) could be transported safely if dissolved in acetone. This expanded the uses of acetylene. Then, too, during World War I, he pro duced liquid chlorine for use in poison gas attacks. And in 1917 he developed something very much like the Haber process independently of Haber [977]. He helped supply Ramsay [832] with liquid air in which to conduct his search for the inert gases. Then, when Ramsay had found them, Claude grew interested in them and worked successfully on their separation from air and their production in quantity. His researches, beginning in 1910, showed that electric discharges through these gases could be made to produce light, and this was the beginning of neon lights, which made Claude rich. The fact that tubes filled with neon or other gas could be twisted into any shape, so that they could spell out words, for instance, made it inevitable that they replace ordi nary incandescent bulbs in advertising signs. In the 1930s such tubes were coated internally with fluorescent mate rials so that a white light was produced that would be acceptable for homes and factories. After World War II fluores cent lights began to replace the old in candescent bulbs that had come in with Edison [788] three quarters of a century before. During World War II, Claude was a supporter of the Vichy government. He was convicted as a collaborationist in 1945 after France had been liberated and, despite his age, spent the next five years in prison. [990] PERRIN, Jean Baptiste (peh-ran') French physicist
1870
Died: New York, New York, April 17, 1942 Perrin’s father died of wounds re ceived in the Franco-Prussian War soon after the infant was born and he was raised by his mother. He obtained his doctorate in 1897 at the École Normale Supérieure in Paris. He was appointed professor of physical chemistry at the University of Paris in 1910 and remained there for thirty years. He was strongly in favor of Boltz mann’s [769] statistical treatment of atomic motions and against the non atomic views of Ostwald [840] and Mach [733].
During the 1890s he was attracted to the study of cathode rays, which Crookes [695] had shown to be electri cally charged. Even so, there remained controversy over whether they were par ticles (as it seemed they would have to be if they were charged) or whether Crookes’s observations were in error and they were actually a form of wave radia tion. Perrin settled the matter once and for all in 1895 by showing that the radi ation could be made to impart a large negative charge to a cylinder upon which they fell. The cathode rays must, there fore, consist of negatively charged mate rial, and must be particles rather than waves. Almost immediately thereafter, J. J. Thomson [869] was able to deter mine the mass of the particles and to show that they were much smaller than atoms.
Download 17.33 Mb. Do'stlaringiz bilan baham: 
|