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121 [190] GLAUBER
BORELLI [191] Glauber made a number of discoveries that mark him as a legitimate “dawn- chemist,” even if his interest in cure-alls was an alchemical hangover. He pre pared a variety of compounds of the metals then known. These included tar tar emetic, an antimony salt which has some medical use. In 1648 he moved to Amsterdam, where he took over a house that had once belonged to an alchemist. He made out of it the best chemical laboratory of the day, with special furnaces and equip ment that he himself had designed. One furnace had a chimney, the first ever to be so equipped. This was all symbolic of the passage from alchemy to chemistry taking place in the seventeenth century. Glauber prepared a variety of chemi cal compounds by secret methods and sold them for medicinal purposes. In working with vinegar, oils, coal, and other substances, he obtained organic liquids such as those we now call ace tone and benzene. He did well and, at one time employed five or six workmen in his laboratories. He always modeled himself on Paracelsus [131], whom he greatly admired and to whose grave he made a pilgrimage. Glauber was ahead of his time in his clear-sighted view of how a country’s natural resources could be exploited for the betterment of living conditions, and he published a book suggesting what Germany should do in this respect. He objected, for instance, to the overexport of raw materials to Austria and France. The political fragmentation of seven teenth-century Germany made his ideas impractical, however. Glauber’s concern with medicinal compounds carried a penalty. What is useful at one dose may be toxic at a larger one, and what is harmless in a sin gle administration may be dangerous in several. Glauber’s death was hastened, it is believed, by poisoning during the slow and tedious work over his compounds and he died poor and discouraged. Other chemists since Glauber’s time have been gradually killed by their work, the most notable case perhaps being that of Ma dame Curie [965].
(boh-reFlee) Italian mathematician and physiol ogist
Born: Naples, January 28, 1608 Died: Rome, December 31, 1679 Borelli, the son of a Spanish soldier stationed in Naples, was a professor of mathematics at Messina in 1649 and at Pisa in 1656. He returned to Messina in 1667.
His life was not entirely smooth. In 1674 he was suspected of political con spiracy against the occupying Spaniards and had to leave Messina again and re tire to Rome, where he remained under the protection of Christina, former queen of Sweden. (This was the queen whose eccentric habits had brought on the death of Descartes [183]. She ab dicated in 1654 and was received into the Roman Catholic Church the follow ing year, after which she settled in Rome.) Borelli corrected some of Galileo’s overconservatism. Galileo had neglected Kepler’s [169] elliptical orbits, but now Horrocks [200] had extended them even to the moon, and Borelli rescued the ellipses, publicizing and popularizing them.
He tried to extend the vague notions of Galileo and Kepler concerning the at tractive forces between the sun and the planets but was not successful. He tried also to account for the motion of Ju piter’s satellites by postulating an attrac tive force for Jupiter as well as for the sun. In this he (and Horrocks also at about this time) made a tentative step in the direction of universal gravitation, but that had to wait a generation for Newton [231],
Borelli suggested (under a pseud onym) that comets traveled in parabolic orbits, passing through the solar system once and never returning. (The parab ola, like the ellipse, was first studied by Apollonius [49]. A parabola is an open curve something like a hairpin.) Any body following a parabolic path would approach the sun from infinite space, round it, and recede forever. Such an 122 [192] TORRICELLI TORRICELLI
orbit would explain the erratic behavior of comets without completely disrupting the orderliness of the universe. Borelli understood the principle of the balloon, pointing out that a hollow cop per sphere would be buoyant when evac uated, if it were thin enough, but that it would then collapse under air pressure. It did not occur to him that collapse could be avoided if a lighter-than-air gas were used to fill the sphere as, in es sence, the Montgolfier brothers [325] were to do a century and a half later. Borelli grew interested in anatomy through his friendship with Malpighi [214]. He tried to apply the mechanistic philosophy to the working of the body after the style of Descartes and here he achieved his greatest fame. In a book en titled De Motu Animalium (“Concern ing Animal Motion”), he successfully ex plained muscular action on a mechanical basis, describing the actions of bones and muscles in terms of a system of levers. In it, also, he made careful studies of the mechanism of the flight of birds as Leo nardo da Vinci [122] had done a century and a half earlier. He attempted to carry these mechani cal principles to other organs such as the heart and lungs with somewhat less suc cess and to the stomach with (as we now understand) no success at all. He consid ered the stomach a grinding device and did not recognize that digestion was a chemical rather than a mechanical pro cess.
This tendency to overmechanization of the body was in part neutralized by the labors of contemporaries such as Sylvius [196], who interpreted the body in purely chemical terms. [192] TORRICELLI, Evangelista (tor- rih-cheriee) Italian physicist Born: Faenza (near Ravenna), October 15, 1608 Died: Florence, October 25, 1647 Torricelli, left an orphan at an early age, received a mathematical education in Rome. He was profoundly affected when in 1638 he first read Galileo’s [166] works. A book he himself wrote on mechanics in turn impressed Galileo, who invited him to Florence. Torricelli went gladly to meet the blind old man and served as his secretary and compan ion for the last three months of his life. He then succeeded him as court mathe matician to Grand Duke Ferdinand II of Tuscany [193] and learned how to make the best lenses for telescopes yet seen. Galileo suggested the problem through which Torricelli was to gain fame. The ability to pump water upward was attributed to the supposed fact that “Na ture abhors a vacuum.” When a piston was raised, a vacuum would be produced unless the water within the cylinder lifted with the piston. Since a vacuum could not occur in nature, it was thought, the water had to lift. But in that case it ought to lift upward indefinitely as long as the pump worked. Water, however, could only be raised about thirty-three feet above its natural level. Galileo, who accepted the vacuum- abhorrence of nature (despite his many revolutionary deeds he was surprisingly conservative in many ways), could only suppose that this abhorrence was limited and not absolute. He suggested that Tor ricelli look into the matter. It occurred to Torricelli that this was no matter of vacuum-abhorrence, but a simple mechanical effect. If the air had weight (according to Aristotle [29] it didn’t but tended rather to have “levity” and to rise but Galileo had shown that a full balloon weighed more than an empty one) then this weight would push against the water outside the pump. When the piston was raised, that push would force the water up with the piston. However, suppose the total weight of the air would only balance thirty-three feet of water. In that case, further pumping would have no effect. The weight of the air would push water no higher. In 1643, to check this theory Torricelli made use of mercury, whose density is nearly thirteen and a half times that of water. He filled a four-foot length of glass tubing, closed at one end, stoppered the opening and upended it (open end 123 [192] TORRICELLI HEVELIUS
down) into a large dish of mercury. When the tube was unstoppered, the mercury began to empty out of the tube as one might expect, but it did not do so altogether. Thirty inches of mercury remained in the tube, supported by the weight of the air per unit area, or “pressure,” pressing down on the mer cury in the dish. The weight of the air could easily be used to account for the mercury column’s remaining in place in defiance of gravity. Above the mercury in the upended tube was a vacuum (except for small quantities of mercury vapor). It was the first man-made vacuum, and, thanks to the publicity given the experiment by Mersenne [181], is called a Torricellian vacuum to this day. (Seven years later Guericke [189] produced a vacuum on a far larger scale by pumping and did dra matic things as a result.) Torricelli noticed that the height of the mercury in the tube varied slightly from day to day and this he correctly at tributed to the fact that the atmosphere possessed a slightly different pressure at different times. He had invented the first barometer. (The pressure of the atmosphere is equivalent to that of a column of mer cury 760 millimeters high. The pressure exerted by one millimeter of mercury is sometimes defined as one torricelli, in honor of the physicist.) The fact that air had a finite weight meant it could only have a finite height, a view confirmed by Pascal [207] a few years later. This was the first definite in dication (aside from philosophical specu lation) that the atmosphere does not ex tend indefinitely upward and that the depths of space must be a vacuum. Thus, far from a vacuum being an im possibility, it is undoubtedly the natural state of most of the universe. Questions concerning the existence of a vacuum may have seemed rarefied and philosophical, but the proof of its exis tence led by a chain of events and rea soning to the development of the steam engine, the advent of the Industrial Rev olution, and the making of our own technological society. All resulted from the upending of a tube of mercury. 124 Torricelli died of typhoid fever only four years after his great experiment. [193] FERDINAND II OF TUSCANY, Grand Duke Italian .ruler Born: luly 14, 1610 Died: May 24, 1670 Ferdinand II was of the famous family of the Medici, who were, in his time, past their best days. Ferdinand succeeded to the ducal throne in 1621 when he was only eleven, and his reign was largely disastrous for Tuscany, which became and remained a cipher in the European arena from then on.
He is remarkable, however, for the eager and liberal patronization of men of science, including Steno [225] and Gali leo [166] and for helping support the foundation of the Accademia del Ci- mento in 1657. He was a deeply religious man, and though he was a political antagonist of the pope, he could not bring himself to challenge the church on matters of her esy. He did not, therefore, come to Gali leo’s defense and for this the world of science blamed him severely. He made a personal contribution to technology. In 1654 he devised a sealed thermometer which, unlike Galileo’s open one, was not affected by changes in air pressure. This led, eventually, to the perfected instruments of Fahrenheit [254] sixty years later. [194] HEVELIUS, Johannes (heh-vay'- lee-oos)
German astronomer Bom: Danzig (now Gdansk, Po land), January 28, 1611 Died: Danzig, January 28, 1687 Hevelius was one of ten children of a prosperous brewer. As a young man, he toured Europe and, having obtained his education en route, returned to Danzig at the age of thirty. An eclipse of the sun, which he had observed in 1639, had turned his attention to astronomy, so he [194] HEVELIUS
GASCOIGNE [195] established an astronomical observatory, the best in Europe at that time, atop his house.
He concentrated on the moon, study ing its features with a succession of tele scopes of greater and greater power. The manufacture of these telescopes was made easier by Hevelius’ construction of a lathe to be used in the grinding of large lenses. Galileo [166], the first to study the moon by telescope, was also the first to try to draw its features. His drawings, however, were only crude sketches. He velius, a generation later, was the first to make drawings containing features of the lunar surface as we recognize them today. In 1647 he published a magnificent volume called Selenographia, an atlas of the moon’s surface, using hand-engraved copper plates for his illustrations. He titled the features systematically, using names taken from earth’s geography, in line with the notion that had become widespread after Galileo’s time that the moon was but a smaller earth. Thus, he named the lunar mountain chains Alps, Apennines, and so on, and these names persist. The dark, relatively flat areas of the moon, he called “seas” (maria in Latin), so that there is a Mare Serenitatis (“Pacific Ocean”) on the moon as on the earth. The maria retain their name to the present time, even though it is now known that they are but dry stretches of dust. Hevelius’ names for the individual cra ters, however, did not last. For this, his older contemporary Riccioli [185] can take credit. In 1644 he made out the phases of Mercury, a necessary accompaniment to Galileo’s discovery of the phases of Venus a generation before. Next to his work on the moon, He velius is best known for his two large volumes on comets. He listed what infor mation he could find on all the comets recorded in the past and discovered four more. The best he could do in connec tion with cometary orbits was to suggest like Borelli [191] that they might be pa rabolas.
Although he observed the physical fea tures of the moon with telescopes, he re fused to use them for measuring the po sitions of the stars. He was the last im portant astronomer to insist on naked- eye observations, and there was reason to it, considering the imperfections of the telescopes of the day. Hevelius got into an acrimonious de bate on the subject with the ever quar relsome Hooke [223], and in 1679 he en tertained for two months a young Englishman named Halley [238] who had come to make peace between him and Hooke. Unfortunately Hevelius’ ob servatory burnt down shortly afterward. The tragedy embittered him and made him intransigent and not inclined to ac cept peace. Hevelius also prepared a star catalogue of 1,564 stars, which was at least as ac curate as that of Tycho Brahe [156]; but it was not published till 1690, after his death.
[195] GASCOIGNE, William (gas'koin) English astronomer Born: Middleton, Yorkshire, about 1612 Died: Marston Moor, Yorkshire, July 2, 1644 Gascoigne did not have much of an education but picked up enough knowl edge of astronomy to engage in compe tent correspondence on the subject and to make two important advances. The telescope, first used to study the astronomical objects by Galileo [166] was scarcely suitable for determining the exact position of those bodies. It was for that reason that Hevelius [194] scorned it and depended on the eye alone. To convert the telescope to such use, Gas coigne devised cross hairs in the focal plane so that an object in view could be accurately centered at the intersection, and a micrometer with which to measure accurately small angular separations of one star from another. It was this that began the conversion of the telescope from a mere viewing toy to an instru ment of precision.
[196] SYLVIUS
WALLIS [198] Gascoigne fought for King Charles I in the English Civil War and died at the Royalist defeat at Marston Moor. [196] SYLVIUS, Franciscus Dutch physician Born: Hanau, Prussia, March 15, 1614
Died: Leiden, Netherlands, November 19, 1672 Sylvius’ name is a Latinized version of his real name, Franz de la Boe (duh-lah- boh-ay'). He was born of Dutch parents who had sought refuge in Germany from the Spanish armies that were trying to subjugate their homeland. Sylvius ob tained his medical degree in Basle, Swit zerland and then, after some years, re turned to the Netherlands, which had won a hard-earned independence. In 1658 he became professor of medicine at the University of Leiden. His contem porary Borelli [191] followed Descartes [183] in viewing the body as a mechani cal device, but Sylvius followed Para celsus [131] and Helmont [175] in view ing it as a chemical device, bringing the former’s “iatrochemistry” to a peak of systematization. Sylvius strongly supported Harvey’s [174] view of the circulation of the blood and was the first to abandon the theory that the health of the body de pended on the relative proportions of the four chief fluids or “humors” that it con tained (blood, phlegm, black bile, and yellow bile), a theory dating back to Greek medicine. Instead, he stressed the opposing properties of acids and bases and their ability to neutralize each other. Viewing the body as a balance of acid and base, though insufficient, is certainly far nearer to what we now believe than was the old notion of the four humors. Sylvius and his followers studied diges tive juices (pointing out that saliva was one of them) and correctly believed di gestion to involve a fermenting process. He is credited with having developed the alcoholic drink gin and having used it to treat kidney ailments. He may also have organized the first university chem istry laboratory. [197] WILKINS, John English scholar
1614
Died: London, November 19, 1672
Wilkins, the son of a goldsmith, en tered Oxford in 1627, obtaining his master’s degree in 1634, and was or dained a few years later. Eventually, he married the sister of Oliver Cromwell, who controlled England with a firm hand during the 1650s. Wilkins spent most of his time on the ology but he contributed to science in two ways. First, he was a powerful spokesman for the Copernican view, in books written for the intelligent layman. He laid great stress on the fact that the astronomical bodies, the moon in partic ular, were worlds, and that therefore they might be inhabited. In 1640 he even speculated that methods might be discov ered whereby the moon could be reached. In this he may have been in spired by the appearance in 1638 of a very popular work of fiction Man in the
with such a flight (though by the roman tic notion of having geese hitched to a chariot after which they fly to the moon). Wilkins’ book reinforced the impres sion of the earlier one and gave rise to thoughts of space flight, both in fiction and fact, that have continued to this day. Second, Wilkins was one of the mov ing spirits behind the founding of the Royal Society. [198] WALLIS, John English mathematician Born: Ashford, Kent, December 3, 1616
Died: Oxford, November 8, 1703 Wallis was the son of a rector who died when Wallis was six. Wallis was himself ordained in 1640. By then he had obtained both a bachelor’s and a master’s degree from Cambridge, having aimed at medicine as his profession. England was in turmoil. The English Download 17.33 Mb. Do'stlaringiz bilan baham: |
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