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496 [764] GOLGI
ABNEY [765] perceptible discs with boundaries that are fuzzy because of their atmospheres. This makes it difficult to determine the precise time when they make apparent contact with the sun. It occurred to Gill, as it had previously occurred to Galle [573], that observation of the more prominent asteroids, which were starlike points of light, might be more profitable, even though the asteroids were further than either Venus or Mars. By 1889 he had completed such observations with heartening results and obtained the first determination of the sun’s distance with modem accuracy in 1901. Nine years later, the asteroid Eros was discovered and was found to have an un precedented orbit lying between Mars and the earth. It could approach the earth to within 15 million miles (closer than either Mars or Venus). Gill’s initial efforts were therefore improved upon by Jones [1140] a generation later at the time of a close approach of Eros to the earth.
From 1879 to 1907 Gill was astrono mer royal at the Cape of Good Hope Observatory. In 1882 he photographed a comet, and the number of stars on the plate convinced him that stellar photog raphy was eminently practical. From his strategically placed post in the south ern hemisphere, he swept the heavens photographically—the first to perform this service for the southern stars. With Kapteyn [815] he extended Argelander’s [508] star chart to the south celestial pole. He was knighted in 1900. [764] GOLGI, Camillo (gole'jee) Italian histologist
Golgi [renamed in his honor] Brescia), July 7, 1843
21, 1926 Golgi, the son of a physician, entered medicine and obtained his degree in 1865 from the University of Padua, going on to do his research at the Uni versity of Pavia. At first he gravitated to ward psychiatry, but he came under the influence of Virchow’s [632] work and devoted himself thereafter to the study of cells and tissues. In 1873 he published the key discov ery of his life. Cellular staining was being brought into prominence by men such as Flemming [762], Koch [767], and Ehrlich [845], but they used organic dyes. Golgi, on the other hand, intro duced the use of silver salts. By staining with this material, cellular components were revealed that are still called by such names as Golgi bodies and Golgi com plex. These, first detected in the brain of a bam owl in 1898, have fascinated cytologists ever since, but their functions remain largely unknown. Eventually Golgi applied his staining methods to nerve tissue in particular and found it well adapted for the purpose. He was able to see details not visible be fore, to make out the fine processes of the nerve cells in unprecedented detail, to distinguish different types of Golgi cells and to bear out Waldeyer’s [722] contention that the apparently joining fibers of different nerve cells did not re ally join, but left tiny gaps called syn apses. Knowledge of the fine structure of the nervous system dates from this work and from that of Ram6n y Cajal [827], who carried on the Golgi techniques. Golgi was appointed professor of anat omy at the University of Siena in 1879 but transferred to the chair of histology and pathology at the University of Pavia the next year. There he ultimately served as president of the university. In the 1880s he turned his attention to malaria, which was making medical headlines as a result of Laveran’s [776] discovery that it was caused by a protozoan. Golgi showed the difference between several varieties of the disease. In 1906 he shared with Ramon y Cajal (with whom he disagreed bitterly on points of theory) the Nobel Prize in medicine and physiol ogy for the work he did on the structure of the nervous system. [765] ABNEY, Sir William de Wive- leslie English astronomer Born: Derby, July 24, 1843 Died: Folkestone, Kent, December 2, 1920 497 [766] CHAMBERLIN KOCH
Abney, the son of a clergyman, gradu ated from the Royal Military Academy and served with the Royal Engineers in India. He was invalided home, however, and with no military career to occupy him, he grew interested in photography. In 1874 he invented a dry photo graphic emulsion (clearly easier to han dle than a wet one) and used it to pho tograph a transit of Venus across the sun in December of that year. He then devised a red-sensitive emul sion which made it possible to photo graph, for the first time, the solar spec trum in the infrared in 1887. This made it possible to determine how sunlight was altered in passing through the atmosphere since some of the infrared was absorbed by air.
Working in the infrared also made it possible to detect absorption region caused by molecules rather than by in dividual atoms. In 1882, therefore, Ab ney was the first to try to correlate spec troscopic absorption with the structure of organic molecules (something that was to lead a century later to the determina tion of molecular structure in distant interstellar clouds of dust and gas). He was knighted in 1900. [766] CHAMBERLIN, Thomas Chrow- der American geologist Born: Mattoon, Illinois, Septem ber 25, 1843 Died: Chicago, Illinois, Novem ber 15, 1928 Chamberlin was the son of a farmer who left North Carolina for Illinois be cause he disapproved of slavery. Cham berlin graduated from Beloit College in 1866 and did graduate work at the uni versities of Michigan and Wisconsin. By 1873 he was professor of geology at Beloit and in 1887 he became president of the University of Wisconsin. As a geologist Chamberlin was partic ularly interested in glaciers and was one of the first to see that there was not one Ice Age but several. In delving further and further back in time, he found him self speculating not merely on the earth’s youth, but on its birth. In 1900 he revived a notion that Buffon [277] had advanced a century and a half earlier. Chamberlin, together with Moulton [1003], suggested that a star had passed close to our sun, that matter had been raised from both stars by tidal forces, that these cooled into small fragments (planetesimals), which further coalesced into the planets. This planetesimal hypothesis still holds good in part, for many geophysicists such as Urey [1164] believe the planetary bodies were built up at moderate temperatures out of smaller fragments though they consider these fragments were never part of the sun. Despite its formidable championship a quarter century later by Jeans [1053], the hypothesis of stellar collisions or near collisions steadily lost popularity. The planetesimals are now considered to have arisen out of a turbulent cloud of dust and gas, as suggested by Weizsacker [1376].
[767] KOCH, (Heinrich Hermann) Robert (kokh) German bacteriologist
over (now in Lower Saxony), De cember 11, 1843
27, 1910 Koch, one of thirteen children of a mining official, obtained his medical de gree in 1866 at the University of Got tingen, where Wohler [515] and Henle [557] were among his teachers. He grad uated cum laude but showed no particu lar sign that he was destined to be, along with Pasteur [642], the founder of mod em medical bacteriology. He dreamed, in fact, of being an explorer, but his wife (less romantic than he) quashed that no tion. (Late in life he had his revenge, for he divorced her and married a much younger woman, shocking the Victorian society of the times.) After serving as an army surgeon on the Prussian side dur ing the Franco-Prussian War, Koch set tled down to the life of a country doctor near Breslau in Silesia. An anthrax epidemic struck the cattle 498 [767] KOCH
KOCH [767] in the area, and Koch studied the dis ease. Painstakingly in 1876 he obtained the bacterium causing anthrax from the spleen of infected cattle and transferred it to mice, carrying the infection from mouse to mouse and recovering the same bacilli in the end. More important still, he learned to cultivate the bacteria out side the living body, using blood serum at body temperature. In this way he was able to follow the entire life cycle of the anthrax bacillus and to study its method of forming resistant spores. Koch brought his work to the atten tion of the bacteriologist Cohn [675], who was teaching at the University of Breslau. Cohn invited the young doctor to his laboratory, studied his work, and enthusiastically sponsored the paper that Koch thereafter wrote. Koch, enjoying a growing fame, trans ferred his labors to Berlin and developed two points of technique that were all im portant. First he made use of the aniline dyes that had been synthesized since Perkin’s [734] time. These he tested for their possible use in staining bacteria for easier study. (Unstained bacteria are semitransparent and therefore hard to see.) Furthermore, having made use of li quid media to grow bacteria outside an organism, Koch advanced to the use of solid media such as gelatin in the form of gels. Agar-agar, a complex carbohy drate obtained from seaweed, was a par ticularly good gel for the purpose. It is not itself edible, but a nutrient broth could be mixed with it. Originally, Koch used flat glass slides for the purpose, but an assistant, Julius Richard Petri, substi tuted shallow glass dishes with covers in 1887. Such Petri dishes have been used for the purpose ever since. On such gels, bacteria could not move about, so that if one bacterium happened to be isolated on one spot of the me dium, it would, by division and redivi sion, give rise to a patch of descendent bacteria, a colony consisting of members of one species all clumped together. Bac teria could then be transmitted to ani mals or allowed to start new cultures in the full knowledge that it was of a par ticular strain. In liquid media, however, a number of varieties of bacteria were endlessly mixed and it was a tedious chore to attempt to separate them. Koch’s solid media may be said to mark the beginning of a rationalized system of bacterial culturing and to mark the final victory of Pasteur’s germ theory. Koch established rules for properly identifying the causative agent of a dis ease. The microorganism must be located in the diseased animal. After being cul tured, it must be capable of causing the disease in a healthy animal. The newly diseased animal must yield bacteria of the same sort found in the original ani mal.
Using his rules and his techniques, Koch isolated the specific bacteria of a number of diseases. His most remarkable discovery and the high point of his ca reer was his discovery in 1882 of the tubercle bacillus, the causative factor of the dreaded disease tuberculosis. (This led him eventually to a search for a cure and in 1890 he thought he had one, an nounced it as such, and, to his intense disappointment, found the announce ment had been premature.) In 1883 he traveled to Asia to study bubonic plague and cholera and to Africa to study sleeping sickness. For his discovery of the cholera bacillus he re ceived a government gift that was the equivalent of $25,000, and was ap pointed professor of hygiene at the Uni versity of Berlin in 1885. He was able to show, between 1897 and 1906, that the bubonic plague was transmitted by means of a flea that infested rats, while sleeping sickness was transmitted by the tsetse fly. This, together with the work of Laveran [776] and Ross [876] on ma laria, pointed out new methods for the control of disease. Rather than a frontal attack on the bacteria themselves, the in sect vector carrying the disease from per son to person could be fought. The germ by itself is helpless (and man is safe) when the insect carrier is destroyed or immobilized. A generation of bacteriologists re ceived training and inspiration working with Koch. Gaffky [805], who accompa nied Koch on his Asian travels, was one, and Kitasato [870] was another. The
[768] STRASBURGER MIESCHER
Nobel Prize winners Behring [846] and Ehrlich [845] were also among Koch’s assistants in their younger days. In 1905 Koch was awarded the Nobel Prize in medicine and physiology, pri marily for his discoveries in connection with tuberculosis. [768] STRASBURGER, Eduard Adolf (shtrahs'boor-ger) German botanist
1, 1844
Died: Poppelsdorf, near Bonn, May 19, 1912 Strasburger, bom of German parents in what was then Russian territory, stud ied in Warsaw and at the Sorbonne in Paris. He profited from hearing lectures by Nageli [598] and Haeckel [707], He received his doctorate at the University of Jena in 1866 and was appointed pro fessor of botany there in 1869, moving on to the University of Bonn in 1880. He was one of the pioneers of cytology, studying the behavior of the plant cells during mitosis. He observed the union of nuclei when the sex cells of plants joined in the course of fertilization. In 1882 he invented the terms “nu cleoplasm” for the protoplasm within the nucleus and “cytoplasm” for the proto plasm outside it. In 1888 he showed that sex cells have only half the number of chromosomes of body cells, a fact that is crucial for the understanding of sexual reproduction. In 1891 he demonstrated that fluids moved upward through stems by physi cal forces such as capillarity, rather than by primarily physiological ones. [769] BOLTZMANN, Ludwig Edward (bohlts'mahn) Austrian physicist
in Austria, now in Italy), Septem ber 5, 1906 Boltzmann, the son of a civil servant, received his Ph.D. from the University of Vienna in 1866. His work on the ki netic theory of gases was done indepen dently of Maxwell [692] and they share the credit. Beginning in 1871, Boltzmann in creased the rigor of the mathematical treatment and emphasized the statistical interpretation of the second law of ther modynamics, thus founding “statistical mechanics.” He showed that Clausius’ [633] concept of increasing entropy could be interpreted as increasing degree of disorder, laying the groundwork for the later achievements of Gibbs [740], He was a firm proponent of atomism at a time when Ostwald [840] was mounting the final campaign against it. Boltzmann also advanced a mathe matical treatment that explained the manner in which, according to the exper imental observations of Stefan [715] (whom Boltzmann, in his college years, served as assistant), quantity of radia tion increased as the fourth power of the temperature. This is therefore sometimes called the Stefan-Boltzmann law. Boltzmann turned down a chance to succeed Kirchhoff [648] at Berlin but in 1894 succeeded to Stefan’s post in Vienna. Though Boltzmann lived longer than Maxwell, his life too was cut short. In his case it was suicide, brought on by recurrent episodes of severe mental depression accentuated, perhaps, by op position to his atomistic notions by Ost wald and others. His equation relating entropy and dis order was engraved on the headstone of his grave. [770] MIESCHER, Johann Friedrich (mee'sher) Swiss biochemist Born: Basel, August 13, 1844 Died: Davos, August 26, 1895 Miescher was the son of a physician. His great moment came in 1869 when he isolated a substance containing both nitrogen and phosphorus from the rem nants of cells in pus. Hoppe-Seyler [663], who was Mie- scher’s teacher, was much astonished, for 500 [771] MANSON
CANTOR [772] lecithin, which he himself had discovered, was the only natural substance known, up to that time, to contain both nitrogen and phosphorus. Hoppe-Seyler refused to allow Miescher’s work to be published for two years until he investigated mat ters himself and discovered a similar substance in yeast. Because the substance seemed to arise from the cell nuclei, it was named nuclein. The name, later modified to nucleic acid, persists to the present day, although such substances have been found to exist in the cytoplasm as well as in the nu cleus.
Later he found that nucleic acid and a simple protein called protamine existed in salmon sperm. He also noted that it was the carbon dioxide concentration in the blood, and not the oxygen concen tration, that governs respiration rates. He was another of those scientists who died prematurely of tuberculosis. [771] MANSON, Sir Patrick Scottish physician Born: Old Meldrum, Aberdeen shire, October 3, 1844 Died: London, England, April 9, 1922
Manson, the son of a bank manager, studied at Aberdeen University, getting his medical degree in 1866. He was sta tioned a year later in Formosa (now Taiwan) as medical officer to the Chi nese Imperial Customs. He settled in Hong Kong in 1883 and founded a school there that eventually became the University of Hong Kong. He stayed in the Far East twenty-three years and helped introduce vaccination to the Chi nese. His experiences there roused his in terest in tropical medicine, which he es tablished as a distinct specialty, founding a school in that field in London in 1899. (He is sometimes called the father of tropical medicine.) He studied elephantiasis, for instance, in which there is a gross swelling of legs or other portions of the body resulting from infestation by certain worms. He was also the first to suggest that mosqui toes might be the agents for the spread ing of malaria, something that was to bear valuable fruit with Ross [876], His work led to the founding of the London School of Tropical Medicine in 1899, where he taught until his retire ment in 1914. He was knighted in 1903. [772] CANTOR, Georg German mathematician
grad), Russia, March 3, 1845 Died: Halle, Saxony, January 6, 1918
To designate Cantor by nationality is difficult. He was bom in Russia, but his father, a well-to-do merchant, had emi grated to Russia from Denmark, and then left Russia for Germany when young Georg was only eleven. And in addition, the family was of Jewish de scent, though his mother was bom a Roman Catholic and his father was con verted to Protestantism. Even as a schoolboy Cantor showed talent for mathematics and eventually (over his father’s objections) he made mathematics his profession. Weierstrass [593] and Kronecker [645] were among his teachers, and in 1867 he obtained his Ph.D. magna cum laude from the Uni versity of Berlin with a paper dealing with a point Gauss [415] had glossed over. He obtained an academic position at the University of Halle, advancing to a professorial appointment in 1872. In 1874 Cantor, after an exchange of letters with Dedekind [688], began to in troduce his intellect-shaking concepts of infinity. The notion of the infinite (sheer endlessness as exemplified, for instance, by the series of integers 1, 2, 3, . . .) had disturbed thinkers since the time of Zeno [16] twenty-three centuries earlier, and not all their thoughts had yet pro duced any clear-cut decision. Cantor decided that to deal with the infinite, one must set up correspondences between two series. For instance, it is possible to match up the integers 1, 2, 3, . . . with the set of even integers 2, 4, 6, . . . in such a way that each integer Download 17.33 Mb. Do'stlaringiz bilan baham: 
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