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161 [242] POLHEM
NEWCOMEN [243] phlogiston theory was that it did not take into account changes in weight during combustion or rusting. Thus charcoal in burning lost almost all its weight, leaving only a light ash. Metals, in rusting, actu ally gained weight, as Boyle [212] had shown a half century earlier. Thus the loss of phlogiston either decreased or in creased weight, depending on cases. Stahl apparently was not perturbed at this because he was still an adherent of the alchemical system of qualitative de scription only. The science of physics had been stressing the importance of quantitative measurement for over a century, since the time of Galileo [166], but that view had not penetrated the al lied science of chemistry. Later, when eighteenth-century chemists, under the influence of the great success of Newton [231], began to feel guilty about ignoring weight considerations they tried to intro duce a principle of levity, which was the reverse of gravity. Thus phlogiston, by leaving metal, reduced its levity and made it heavier. This was a foolish no tion, however, and did not last long. Nevertheless phlogiston, with all its contradictions, dominated chemistry for a century until the liberating influence of Lavoisier [334] was felt. Stahl’s influence on physiology was a considerable one, too. He had rational views on mental disease, but on the whole his influence was not an altogether good one from the modern point of view. He did not consider the body ei ther a mechanical system as did Borelli [191], or a chemical system as did Syl vius [196], Instead he believed it fol lowed laws that were different from those ruling the nonliving universe. This view is called vitalism. It remained prominent until the nineteenth century and is not really dead even yet. Stahl’s most prominent contemporary adversary was Boerhaave [248]. [242] POLHEM, Christopher (pool'- hem)
Swedish inventor Born: Visby, Gotland Island, De cember 18, 1661 Died: Tingstàde, August 30, 1751 Polhem, left fatherless at ten, became a clockmaker and entered the University of Uppsala in 1687. He invented a variety of machines for industrial purposes, particularly in min ing. He was an ardent advocate of re placing human muscle with water power and in 1700 built a water-powered fac tory for the manufacture of tools. He also recognized the value of division of labor, something in which he was two centuries ahead of his time, for it was only at the opening of the twentieth cen tury that Ford [929] really put the no tion to work. Outside his native land Polhem built a minting machine for George I of Great Britain. He would not remain in that land, however, nor would he let himself be lured to Russia by Peter I. He was knighted by Frederick I of Sweden. [243] NEWCOMEN, Thomas English engineer Born: Dartmouth, Devonshire, February 24, 1663 Died: London, August 5, 1729 Newcomen was a blacksmith by pro fession but an eager and inquiring one, who was supposed to have consulted with Hooke [223] on the workings of vacuums though this may not be so. In 1698 he went into partnership with Sa- very [236] who had already built a steam engine and who held comprehensive pa tents. Newcomen devised an improved version in which high-pressure steam was never used and air pressure was made to do all the work. For the purpose he had to construct carefully polished cylinders in which pistons could be made to fit with reasonable airtightness. By 1712 such a machine was con structed and by 1725 it was coming into general use, where it remained for over half a century until the Watt [316] en gine replaced it. Englishmen such as Savery and Newcomen foreshadowed the Industrial Revolution a century later, but there were harbingers outside England, too. Polhem [242], a Swede, is an exam ple.
162 [244] AMONTONS
DE MOIVRE [246] [244] AMONTONS, Guillaume (a-mohn-tohn') French physicist Born: Paris, August 31, 1663 Died: Paris, October 11, 1705 Amontons, the son of a lawyer, went deaf while still young, but he considered this a blessing because it permitted him to concentrate on his scientific work. (This view was much the same as that held two centuries later by Edison [788], who was similarly afflicted.) Amontons was interested primarily in the improvement of instruments, particu larly barometers and thermometers. In 1687 he invented a new hygrometer, an instrument for measuring the quantity of moisture in the atmosphere. He also de signed barometers that did not use mer cury and could therefore be used at sea, where the pitching of the waves would ordinarily cause the mercury level to os cillate and destroy the precision of the reading.
As for thermometers, he improved on Galileo [166], who had used air trapped in a tube with a bulb at the end and leading into another tube of water. As the air expanded with a rise in tempera ture, the water level rose; as the air con tracted with a fall in temperature, the water level fell. This thermometer was not at all accurate because changes in air pressure also altered the water level, a point Galileo did not realize. Amontons used a similar air thermom eter, but trapped the air with mercury instead of water. Furthermore the tem perature was read by altering the mer cury height until the air was held at some fixed volume. In this way tempera ture was measured by changing air pres sure rather than changing air volume. Amontons’ thermometer was somewhat more accurate than Galileo’s, and he used it to determine that a liquid such as water always boiled at the same tempera ture (within the limit of precision of his instrument). However, it was still not an instrument for general scientific work; that had to wait two decades for Fahren heit [254], In any case, Amontons’ interest in thermometers led him to consider the effect of changing temperature on gas volume, which had also interested Mari- otte [203]. Amontons went a step be yond Mariotte, however, who had merely shown that the volume of air changed with temperature. Amontons, studying different gases, showed that each gas changed in volume by the same amount for a given change in temperature. Out of this he may have gained a vision of an ultimate cold, a kind of absolute zero at which gases contracted to the point where they could contract no farther. He published his observations on gases in 1699, but they lay fallow for about a century before Charles [343] revived them. Then a half century passed before the important notion of absolute zero was firmly established by Kelvin [652], [245] HAUKSBEE, Francis English physicist
Hauksbee, the son of a draper, became an instrument maker, was a pupil of Boyle [212] and was elected to the Royal Society about 1705. That is virtually all that is known of his private life. He was the first to study capillary ac tion, effects involving the attractive forces between a liquid and a solid; that causes water, for instance, to rise within thin tubes, and spread out over a flat surface.
He was also one of the earliest investi gators of electrical phenomena. His chief advance, made in 1706, was the con struction of a glass sphere, turned by a crank, which, through friction, could build up an electric charge. This was something like Guericke’s [189] sulfur ball but it was much more efficient. [246] DE MOIVRE, Abraham (duh- mwah'vr)
French-English mathematician Born: Vitry-le-Francois, Marne, May 26, 1667 Died: London, England, Novem ber 27, 1754 163 [247] SACCHERI
BOERHAAVE [248] De Moivre, the son of a surgeon, was a Protestant and in his youth, France was growing steadily more intolerant of its Protestant (or Huguenot) minority. In 1685, Louis XIV revoked the Edict of Nantes which had granted them tolera tion, and De Moivre may have been im prisoned for a time. He left France, when he could, and went to England where he remained for the rest of his life, one of the very many talented men whom France lost to its enemies because it could not resist the pleasure of preju dice. De Moivre got to know Newton [231] and Halley [238] and was elected to the Royal Society in 1697, but he never at tained a professorial position and had to make a poor living by tutoring. He advanced the mathematics of prob ability well past where it had been left by Pascal [207] and Fermat [188] and made use of factorial numbers in that connection. He was the first to advance some of the fundamental formulas of probability. He was also the founder of analytical trigonometry. Just as Descartes [183] had converted geometry to algebraic for mulas. so did De Moivres do the same for trigonometry. De Moivres was an early example of what we might call an “industrial mathe matician.” He supplemented his earnings by serving as a consultant to insurance firms, making use of his probability know-how. (He was also consulted by gamblers, naturally.) [247] SACCHERI, Girolamo (sahk- kehriee) Italian mathematician Born: San Remo, September 5, 1667
Died: Milan, October 25, 1733 Saccheri was ordained a priest in 1694 and taught mathematics at the Jesuit College of Pavia from 1697 to his death. He was interested in the fifth postulate of Euclid r^O]- the one that assumes (to put it in one of several alternate forms) that through any point not on a given line, one and only one line can be drawn that is parallel to the given line. It is the only one of the statements with which Euclid starts that cannot be expressed in a few words and that is not intuitively obvious. Many mathematicians, includ ing Omar Khayyam [87] tried to prove the fifth postulate from the remaining axioms and failed. It is quite astonishing and a tribute to Euclid that he saw the difficulty and solved it by accepting it as an assumption and going no further with it. It occurred to Saccheri to try a novel approach. He would assume that the postulate was wrong; that through the point not on a given line, two or more parallels could be drawn to the given line. He would then follow through the consequences and find a contradiction. The existence of the contradiction would prove that more than one parallel could not be drawn and that Euclid was right. He began a systematic consideration of the consequences, went on and on, failing to find a contradiction and grow ing very disturbed because he felt some how that Euclid was a divine truth and to deny it was to deny religion. Eventu ally, he persuaded himself he had found a contradiction when he had, in fact, not done so and, in 1733, published the re sults in a book entitled Euclid Cleared of
standing examples of a failure of nerve in science, for Saccheri was on the point of discovering non-Euclidean geometry when he gave up. It had to wait for over a century for Lobachevski [484] and Bolyai [530], [248] BOERHAAVE, Hermann (boor- hah'vuh) Dutch physician Born: Voorhout (near Leiden), December 31, 1668 Died: Leiden, September 23, 1738 Boerhaave was the son of a clergyman and it was originally intended that he study theology. For that purpose he went to the University of Leiden, where he obtained his Ph.D. in 1689. He became interested in medicine, however, ob
[249] HALES
BERING [250] tained his medical degree at Harderwyck in 1693, and returned to Leiden in 1701 as a physician and one who was to accel erate the process by which Leiden be came for a time the most famous medi cal center in Europe. He spent the whole of his professional life there. He taught medicine by taking his stu dents to the sickbed and was the founder of clinical teaching. Students came to him from all over Europe. Among them was Peter the Great, tsar of Russia, who also took the opportunity of visiting Boerhaave’s compatriot Leeuwenhoek [ 221 ], Boerhaave published the neglected drawings of Swammerdam [224] at his own expense. He also published a text book on physiology in 1708 and one on chemistry in 1724 and each was the most popular of the day and extremely influential. In the former, Boerhaave makes a thoroughgoing mechanistic in terpretation of the body in opposition to Stahl [241]. Though famous for his teaching and his writing, Boerhaave made few original advances of his own. He was the first to describe the sweat glands and he es tablished that smallpox is spread only by contact, but there is little else. Never theless he is possibly the most eminent European physician during the sixteen centuries between Galen [65] and Koch [767] and is sometimes known as the Dutch Hippocrates [22]. The success of his practice may be attested to by the fact that he died an extremely wealthy man. [249] HALES, Stephen English botanist and chemist Born: Bekesboume, Kent, Sep tember 17, 1677 Died: Teddington, Middlesex, January 4, 1761 Hales studied theology at Cambridge, obtaining his master’s degree in 1703, and was a curate at Teddington from 1708 (where the poet Alexander Pope was his neighbor and friend), dabbled in several branches of science and did well enough to be elected a fellow of the Royal Society in 1717. He was strongly influenced by Newton’s [231] work and labored to apply the quantitative experi mental approach to biology. His most important experiments in volved plants, for he measured rates of growth, the pressure of sap, and so on. He recognized that it was a portion of the air that contributed to the nourish ment of plants, finally correcting Hel- mont’s [175] misconceptions of a century before. For this he is considered the founder of plant physiology. Hales was also the first to measure blood pressure. He advanced methods for distilling fresh water from the ocean, for protect ing grain from weevils by the use of sul fur dioxide, and fish from spoiling. He recognized the value of ventilation and he was the first to collect different gases over water. He experimented with such gases as hydrogen, carbon monoxide, carbon dioxide, methane, and sulfur dioxide, but did not clearly recognize these as distinct gases. A book on his discoveries, published in 1727, was the last to receive the official imprimatur of the aged president of the Royal Society, Isaac Newton. In 1753 he was elected one of the eight foreign members of the French Academy. [250] BERING, Vitus Jonassen (bay'ring) Danish-Russian navigator Born: Horsens, East Jutland, Summer 1681 Died: Bering Island, east of Kam chatka (now part of the Soviet Union), December 19, 1741 Bering, the son of an impoverished family, went to sea early. Barely twenty, he went off on a long voyage to the East Indies. When he returned, he was re cruited in 1703 into the Russian navy which, under the direction of the tsar, Peter I (the Great) was being rapidly modernized. Peter wanted Russia’s vast new hold ings in Siberia mapped, and he chose
[251] MORGAONI
REAUMUR [252] Bering for the job. In particular Bering was to discover whether Siberia joined North America. In 1725, he crossed Si beria overland and reached the great far eastern peninsula of Kamchatka, which he was the first to map. From Kamchatka, he set sail north ward in 1728 and reached the Arctic ice without sighting land. He had passed through what is now the Bering Strait and he correctly decided that Siberia and North America were not joined. In a second expedition from Kam chatka in 1741, he explored the Bering Sea (as it is now called), sighted some of the Aleutian Islands but, weakened by scurvy, died on what is now called Bering Island. He was the first to bring Siberia and its eastern shores into the sharp focus of geographic knowledge. [251] MORGAGNI, Giovanni Battista (mawr-gah'nyee) Italian anatomist
ary 25, 1682 Died: Padua, December 5, 1771 Morgagni, an only child, was brought up by his widowed mother. He was a brilliant student at the University of Bo logna while in his teens, graduating in 1701. In his early twenties he assisted mightily in the preparation of a book on the anatomy and diseases of the ear, which pointed his own direction, the anatomy of diseased rather than of healthy tissue. At the age of thirty he became profes sor of anatomy at the University of Padua and remained in that post for nearly sixty years, dying in his ninetieth year. By the time he reached Padua his book on anatomy had established his fame, but the height of his career came in his eightieth year. It was in 1761 that he published a book on the 640 post mortem dissections he had conducted. He tried to interpret the causes and progress of disease from the anatomical standpoint and is considered the father of pathology. [252] RÉAUMUR, René Antoine Fer chault de (ray-oh-myoori) French physicist Born: La Rochelle, Charente Maritime, February 28, 1683 Died: near St.-Julien-du-Terroux, October 18, 1757 Réaumur was the son of a judge who died when the boy was one year old. Réaumur went to Paris in 1703. There a relative, who was an important official, took him under his wing. He did some work in mathematics that was good enough to get him into the Academy of Sciences in 1708. In 1710 he was commissioned by Louis XIV to prepare a description of the various useful arts and manufactures of France, thus giving his active mind the opportunity of ex ploring many branches of science. He prepared a kind of opaque white glass still known as Réaumur porcelain, he showed that certain so-called turquoises found in southern France were really fossil teeth of extinct animals, and he did work on new methods for steel manufacturing, becoming the first to demonstrate the importance of carbon to steel. For the last, which was the first attempt to make a science out of what was almost a secret art, he earned a con siderable cash award, which he turned over to the Academy of Sciences. He wrote a six-volume work on insects, ap plying his observations on the nest making habits of wasps to the improve ment of paper manufacture, and was also the first (in 1750) to design an egg incubator. What’s more, he was the first to demonstrate that corals were animals and not plants. He interested himself in developing a thermometer, anxious to improve on that of Amontons [244], devised a generation before. He apparently did not know of the work of Fahrenheit [254] in the pre vious decade but went on independently. He abandoned the air thermometer used by Galileo [166] and Amontons and in 1731 measured temperature by the ex pansion and contraction of a liquid, using a mixture of alcohol and water for the purpose. The mixture he used ex panded with temperature in such a fash
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