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[610] KOLBE
PETTENKOFER [612] [610] KOLBE, Adolph Wilhelm Her mann (kole'buh) German chemist Born: Elliehausen, Hannover, September 27, 1818 Died: Leipzig, Saxony, November 25, 1884 Kolbe, the eldest of fifteen children of a minister, studied at Gottingen under Wohler [515] and in 1842 served as as sistant to Bunsen [565]. In 1845 he stud ied in London and made the lifelong friendship of Frankland [655]. He re ceived his first professorial appointment at the University of Marburg in 1851, succeeding to the chair that Bunsen had held. He then moved to the University of Leipzig in 1865, remaining there till his death. He was one of the early synthesizers of organic compounds, for in 1845 he synthesized acetic acid and did so from starting materials that were indubitably inorganic. If anyone wished to quarrel with the significance of Wohler’s synthe sis of urea, as starting with something that was organic anyhow, that quarrel was lost. Kolbe (who introduced the term “syn thesis” into chemical usage, by the way) was the first to apply electrolysis to or ganic compounds, and he obtained in teresting organic “double acids” in this fashion. The Kolbe reaction, which he discovered in 1859, made it possible to prepare salicylic acid in quantity and eventually led to the cheap production of the well-known drug, acetylsalicylic acid (aspirin). Kolbe was a conservative force in chemistry, possibly because the aged Berzelius [425] had once praised Kolbe’s work extravagantly, and the younger man retained a sentimental attachment for outmoded Berzelian views. Kolbe was a strenuous opponent of the struc tural theories of Kekule [680] and deliv ered himself in 1877 of an intemperate diatribe against the tetrahedral carbon atom proposed by Van’t Hoff [829] and Le Bel [787]. Kolbe was mistaken in both cases. However, he was an out standing teacher and his good out weighed his bad. [611] DU BOIS-REYMOND, Emil Heinrich (dyoo-bwayTay-mone') German physiologist Born: Berlin, November 7, 1818 Died: Berlin, December 26, 1896 Du Bois-Reymond was of Huguenot stock, hence his French name. He stud ied biology at the University of Berlin under Müller [522] and for his gradua tion thesis in 1843 wrote a paper on electric fishes. This was the beginning of a lifelong interest in the electrical prop erties of animal tissues. Beginning in 1840 he set about refining old instruments and inventing new ones with which he might detect the passage of tiny currents in nerve and muscle, thus founding scientific elec trophysiology. He was able to show that the nerve impulse was accompanied by a change in the electrical condition of the nerve and must have a measurable veloc ity. This upset vitalism in one of its strongholds, for something as ethereal as the silent, unnoticeable impulse that floods along the nerves and brings about the motions and other responses so char acteristic of life, turned out to be inter pretable in terms suited to the inorganic environment. The nerve impulse was closely related to the electricity surging along the dead copper wires of the tele graph. And yet this also revived, in a much more sophisticated manner, Ga len’s [65] notion that the nerves carried a refined and subtle “animal spirit.” When Müller died in 1858, Du Bois-Reymond succeeded him as professor of physiol ogy. In later years he became an impor tant early supporter of Darwin’s [554] theory of evolution. [612] PETTENKOFER, Max Joseph von German chemist
cember 3, 1818 Died: near Munich, Bavaria, Feb ruary 10, 1901 Pettenkofer, the son of a customs official, was stage-struck early in life, but finally abandoned his attempts at acting since it was clear he lacked talent in that direction.
[613] JOULE
JOULE [613] He turned to medicine instead and ob tained his medical degree at the Univer sity of Munich in 1843. He became a professor at that university in 1845. He studied with Liebig [532] and in Liebig’s laboratory discovered creatine, a nitrogenous component of muscle tissue. Neither this nor his association with his student Voit [691] was the most signifi cant of his labors, however. He specialized in hygiene and was one of the first to emphasize the subject as a matter of good health rather than mere good manners. In 1865 he was appointed to a professorship in hygiene at the Uni versity of Munich. The fact that the sub ject was considered worth a profes sorship is an indication of the impor tance his work had lent it. He studied the effect of ventilation on health and of the role played by contaminated soil and water in the spread of cholera. Like Virchow [632] he labored to push through public health measures to con trol such dangers. This sort of work, as much as the great bacteriological studies of Pasteur [642] and Koch [767], wiped out the periodic subjection of Europe to most forms of epidemic disease. Nevertheless, again like Virchow, Pet- tenkofer refused to accept the germ theory of disease. To show his contempt for the theory, he deliberately swallowed a virulent culture of cholera bacteria in 1892. It remains a source of amazement that he did not get the disease. In his old age, he mourned the death of his wife and three children. When an infected sore throat caused him more pain than he felt he ought to have to en dure—and with only a few worn-out years left him in any case—he bought a gun and shot himself. [613] JOULE, James Prescott (jowl or jool)
English physicist Born: Salford, Lancashire, De cember 24, 1818 Died: Sale, Cheshire, October 11, 1889
Joule was the second son of a wealthy brewer, which meant he had the means to devote himself to a life of research. He also suffered poor health as a young ster, having some sort of spinal injury, which meant he could withdraw to his books and studies. His father encouraged him and supplied him with a home labo ratory. He had some instruction from the aged Dalton [389], but by and large he was self-educated and, like Faraday [474], remained innocent of mathe matics. Joule was almost a fanatic on the sub ject of measurement, and even on his honeymoon he took time out to devise a special thermometer to measure the tem perature of the water at the top and bot tom of a scenic waterfall his wife and he were to visit. (His wife died in 1853, after only six years of marriage.) In his teens he was publishing papers in which he was measuring heat in con nection with electric motors. Despite the fact that illness forced his father to retire in 1833 and that young Joule had then to do his share toward running the brewery, he continued his scientific labors. By 1840 he had worked out the formula governing the develop ment of heat by an electric current: The heat developed is proportional to the square of the current intensity multiplied by the resistance of the circuit. He went on to devote a decade to measuring the heat produced by every process he could think of. He churned water and mercury with paddles. He passed water through small holes to heat it by friction. He expanded and con tracted gases. Even his honeymoon mea surement of the waterfall temperature was based on the thought that the energy of falling water should be converted to heat once it was stopped so that the tem perature at the bottom of the waterfall should be higher than that at the top. In all those cases he calculated the amount of work that had entered the system and the amount of heat that came out and he found, as Rumford [360] had maintained fully half a cen tury before, that the two were closely re lated. A particular quantity of work al ways produced a particular quantity of heat. In fact, 41,800,000 ergs of work produced one calorie of heat. This is
[613] JOULE
JOULE [613] called the “mechanical equivalent of heat.” Joule’s first full description of his ex periments and conclusion appeared in 1847. It did not commend itself to most scientists at the time. This may have been due partly to the fact that Joule was a brewer and not an academician. (He never received a professorial ap pointment though he was proposed for one at least once and was rejected, in part because of his spinal injury.) It may have been due partly, too, to the fact that his conclusions were based on small temperature differences in many cases (he used thermometers that could be read to 0.02°F and, eventually, to 0.005°F), so his experiments were not spectacular. His original statement of his discovery was rejected by various learned journals as well as by the Royal Society. He was forced to present it at a public lecture in Manchester and then get his speech pub lished in full by a reluctant Manchester newspaper on which his brother was music critic. A few months later he finally managed to present it before an unsympathetic scientific gathering and his presentation would have passed al most unnoticed but for a twenty-three- year-old in the audience. His name was William Thomson, and he was later to be known as Lord Kelvin [652], His comments on Joule’s work were shrewd enough and logical enough to rouse in terest and even enthusiasm, and Joule’s reputation was made. Later, Stokes [618] also supported Joule’s work with enthusi asm. Full recognition came in 1849 when Joule read a paper on his work be fore the Royal Society, with Faraday himself as his sponsor. Joule was not the first to determine the mechanical equivalent of heat. Rumford had attempted it but had come out with a value that was far too high. Mayer [587] produced a fairly good value be fore Joule did, but it was Joule who was most accurate (up to his time), who backed up his figure with a large variety of careful experimental data, and who (with Thomson’s help) forced the view on the world of science. He therefore gets the credit; and in his honor a unit of work, equal to 10,000,000 ergs, is called the joule (4.18 joules of work equal 1 calorie of heat). The determination of the mechanical equivalent of heat led to something very fundamental. Ever since the time of Newton [231] and even of Galileo [166] it was understood that the energy of an object hurtling upward did not really de cline as its movement slowed. To be sure, that movement steadily diminished under the pull of gravity, but as the ob ject lost kinetic energy (the energy of movement) it gained potential energy (the energy of position). When the ob ject reached its maximum height, it was momentarily stationary and had no ki netic energy at all, but it had a good deal of potential energy. As it started falling, potential energy was reconverted into ki netic energy and when it reached the ground again, it was with all the kinetic energy with which it had originally been hurtled upward. Theoretically, potential energy and ki netic energy interchanged without loss and this was the “conservation of me chanical energy.” In reality the conser vation was not perfect. Some energy was lost through air resistance and friction. However, if heat is recognized as a form of energy; and if it is further rec ognized that the loss of mechanical en ergy through friction or air resistance is balanced by a gain of heat; and if Joule’s point is clear, that the loss of other forms of energy is always exactly bal anced by the gain in heat, then the suspi cion arises that total energy is conserved. This is the law of conservation of en ergy, which states that energy can nei ther be created out of nothing nor de stroyed into nothing, but that it can be changed from one form to another. This is one of the most important general izations in the history of science. It is so important in connection with the study of the interactions of heat and work (the thermodynamics first founded as a sci ence by Carnot [497] two decades ear lier) that it is frequently called “the first law of thermodynamics.” In the century and a quarter since Joule’s time this law has trembled on oc casion, notably when radioactivity was
[613] JOULE
ADAMS [615] discovered and again when the radioac tive emission of electrons was studied in detail. Always, through the work of such men as Einstein [1064] and Pauli [1228] the first law has been reestablished more firmly than before—at least so far. Although Joule recognized the princi ple of the conservation of energy, and so did Mayer before him, the first to pre sent it to the world as an explicit gener alization was Helmholtz [631] and it is usually Helmholtz who is given credit for its discovery. During the 1850s Joule went on to collaborate with his young friend Thom son. Together the two men showed that when a gas is allowed to expand freely, its temperature drops slightly. This ob servation, established in 1852, is called the Joule-Thomson effect and it is taken as evidence for the fact that molecules of gases have a slight attraction for their neighbors. It is in overcoming this attrac tion while moving apart during expan sion that individual molecules lose en ergy and therefore temperature. This turned out to be a very important con sideration in obtaining extremely low temperatures toward the end of the nine teenth century. Men such as Dewar [759] took full advantage of it. Joule also discovered in 1846 the phe nomenon of magnetostriction, whereby an iron bar changes its length somewhat when magnetized. This seemed purely academic at the time, but nowadays the effect is used in connection with ul trasonic sound-wave formation. Joule was elected to the Royal Society in 1850, received its Copley medal in 1866, and was president of the British Association for the Advancement of Sci ence in 1872 and in 1887. That he remained a brewer all his life and was never a professor did not seem to matter in the intellectual democracy of the world of science. Toward the end of his life he suffered economic reverses, but Queen Victoria granted him a pension in 1878. He was a modest and unassuming man, a sincerely religious one, and toward the end of his life bitterly regretted the increasing ap plication of scientific discoveries to the art of warfare. [614] DRAKE, Edwin Laurentine American petroleum engineer Born: Greenville, New York, March 29, 1819 Died: Bethlehem, Pennsylvania, November 8, 1880 Drake was a railway conductor during the first part of his life, but he had invested in a firm that gathered oil from seepages near Titusville, Pennsylvania, and used it for its presumed medicinal properties. It occurred to Drake that more oil might be obtained if one drilled for it as, on occasion, people drilled for brine. He studied the methods used for drilling for brine, and in 1859 he set about using those methods at Titusville. He drilled sixty-nine feet into the ground and on August 28, 1859, he struck oil. He had drilled the first oil well and had begun a procedure that was to revolutionize human uses of energy. In fact, others flew to the site at once and began drilling on their own. North western Pennsylvania became the first oil field in the world and boom towns sprang up. Drake had not patented his methods, however, and he was not a clever businessman. Others were going to grow rich on oil, but Drake was not one of them. He died poor. [615] ADAMS, John Couch English astronomer Bom: Laneast, Cornwall, June 5, 1819
Died: Cambridge, January 21, 1892
Adams, the son of a poor farmer, was self-taught to begin with, but when he finally attended school showed signs of great precocity. He went on to Cam bridge in 1839, entering on a scholar ship, and continued to display brilliance there. He was first in his class in mathe matics when he graduated in 1843. 400 [615] ADAMS
HOWE [616] He began an investigation of Uranus’ motion (since the planet’s motion did not fit the orbit calculated by Bouvard [392] twenty years before) while he was an undergraduate. He did the work on his vacation, for during school sessions his spare time was occupied with tutor ing (to earn money to send home to his parents). By October 1843 he had a so lution, and in 1845 he presented this so lution to his superiors. The incoming astronomer royal, Airy [523], neglected the paper, because he was certain the anomaly of Uranus’ mo tion was the result of imperfections in the theory of gravitation. The matter was not pushed by the unaggressive Adams until it was too late. When Leverrier’s [564] figures were published, Airy was finally stirred to action, though even then he neglected to say that similar figures had reached him from Adams first.
The planet itself was still to be lo cated. But Adams had another bad break. Cambridge Observatory lacked a good map of the region of the sky in which the new planet was thought to be located. The Cambridge astronomer James Challis [535], therefore, did not recognize Neptune as an intruder in the area, although later he found he had ac tually had it twice in his field of vision. (When astronomers checked back, they found the record of an observation of Neptune as far back as 1795.) It was left for Galle [573] with his good map of the area to make the discovery. Adams eventually received his share of the credit, thanks to enthusiastic labors on his behalf by John Herschel [479]. Adams went on to do good, though less spectacular, work in calculating the or bital motion of the Leonid meteor swarm, showing it to have a cometlike orbit. In 1851 he became president of the Royal Astronomic Society and by 1858 was a professor of astronomy at Cam bridge. In 1860 he succeeded Challis as the director of Cambridge Observatory. Many years later, after Airy’s retire ment, Adams was offered the post of as tronomer royal, but he refused because of age. He also refused a knighthood. [616] HOWE, Elias American inventor
July 9, 1819 Died: Brooklyn, New York, Oc tober 3, 1867 Howe, the son of a farmer, gained ex perience in his father’s mill and became a machinist who worked in a factory producing cotton machinery in Lowell, Massachusetts, and later in Cambridge. The fact that every phase of spinning and weaving had come, in the previous century, to be performed by machinery, brought home to him forcefully that sewing in the family was still being done by hand, much as it had been done since before the dawn of civilization. For five years he worked to devise a practical machine that would sew. The key notion upon which he stumbled was that of placing the eye of the needle near the point instead of at the end opposite, and of using two threads, with stitches made by means of a shuttle. In 1846 he obtained his patent and demonstrated its value by racing against five girls sewing by hand, and winning. However, the im pression was unfavorable since the ma chine seemed complicated and threat ened unemployment. He traveled to En gland in order to get it placed on the market there and sold the English rights for a small sum. When he returned to the United States he was destitute. He found his wife dying and others marketing sewing ma chines without paying royalties. He fought the matter through the courts, which took their usual slow and dis couraging time about it. Howe’s patent was finally confirmed and established in 1854 and he was sensible enough to let his competitors continue their work on payment of a reasonable licensing fee. His competitors went on to dominate the field, but Howe lived out the final decade of his life in security, leaving an estate of two million dollars. The sewing machine was the first product of the Industrial Revolution that specifically lightened woman’s household tasks. In 1915 Howe was elected to a
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