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Joseph Steim Office: Room 341 GeoChem Bldg. Joseph_Steim@Brown.edu Phone: 401 863 3249
Class Meets: MWF 10:00 - 10:50 AM (C hour) Room 201, MacMillan Hall
The Triumph of Science Fresco by Nicolo Barabino, Palazzo Orsini, Genoa (detail). Science, a geometry book in her hand, stands levitated over the prostrate figure of ignorance and superstition. Meanwhile, Professor Volta demonstrates his new chemical invention, the electric battery, while a group of eminent natural philosophers, including a very casual Isaac Newton, looks on. |
SYNOPSIS
In his epochal 1808 monograph, A New System of Chemical Philosophy, the great John Dalton postulated atoms, suggested some of their properties, and proposed a method for determining their relative weights. The concept of molecules hardly existed at that time, but with these first tentative steps Dalton started chemists on a great adventure that was to last the entire nineteenth century. At the end, molecules could be visualized in three dimensions, with all the atoms in the right places. Getting there, though, was like negotiating a maze in the dark. There were wrong guesses and awesome insights, blind alleys, incompetent guides and legendary trailbreakers, kind souls and quarrelsome spoilers, praise and ridicule, obstinacy and receptiveness to new ideas, lucky accidents and rationally designed experiments, generosity and selfishness, and brilliant work that was ignored then discovered all over again decades later. Eventually, ideas that accorded with reality survived, sometimes after being resuscitated more than once, and the foolish or mistaken ones succumbed. Science still works that way. The first part of this course recounts this very human tale, the nineteenth-century development of chemistry from Dalton through deciphering molecular architecture Afterwards, you may think of science in a different way.
The last part of the course deals with the role that chemistry played outside the laboratory in those formative years. The science came of age in the nineteenth century, and began to have a major impact upon society. In fact, never before or since has chemistry met with such public approval and widespread interest. Part of the appeal was its intellectual attractiveness and part was its almost mystical, magical charm, but at the same time the benefits were there for all to see: anaesthesia, antiseptics, sanitation, the germ theory of disease (Louis Pasteur was a chemist), fertilizers, new colorful dyes, pharmaceuticals, and so on. From the standpoint of industrialization, the single greatest impact of the new chemistry, and one that everyone who wore clothes could appreciate, was dyes. Synthetic dyes were discovered accidentally in 1856 by an 18-year-old English chemistry student who was born with a good dose of business acumen (he quit college, founded a company, and grew rich), but soon the German dye industry eclipsed England and every other country, and expanded into pharmaceuticals and other products. Today's giant chemical firms such as BASF, Hoechst, and Bayer date from that time. Business practices were sometimes less than honorable, and this changing face of chemistry was beginning to affect the public's impression of the science. The German chemical industry dominated the scene so completely, and chemistry began to play such a role in warfare as well as civilian life, that the Great War of 1914-1918 became known as the chemists' war. Public perception of chemistry, and almost everything else, has not been the same since. All of these events will occupy us during the latter part of the semester.
ORGANIZATION OF THE COURSE
There are no prerequisites… no chemistry, no physics, no math. Just as the chemists started with nothing, so will we. The course is open to everyone, and a special invitation is extended to students of the humanities. However, the contents will also be almost entirely new to science people, including chemistry concentrators and graduate students. A lecture format will usually be followed, but the small class size allows greater interaction than in large lecture courses; student participation is encouraged. The lectures often will be supplemented with demonstrations, usually made with reproductions of period equipment (eg, an electrical machine from the Napoleonic era, and Professor Volta's electric canon).
There will be two take-out exams (one at mid-term and one at the end of the term), two brief papers (1-2 pages), and a longer term paper. Readings, often from the original sources, will be distributed in class.
SYLLABUS
Sept. 6 Enlightenment science: Antoine Lavoisier's new chemistry 8, 11 A meteorologist turns chemist: John Dalton's mechanistic atomic theory (1808) 13 An alternative to atoms: William Hyde Wollaston's system of equivalents 15 Entering the age of electricity: Professor Volta's pile (1800) 18, 20 Romantic science: Sir Humphry Davy's electrochemistry, and some other Davian contributions such as the miner's safety lamp, protecting the ships of the Royal Navy, and poetry 22, 25 The hand of the master: how Jons Jacob Berzelius established his table of atomic weights by using chemical evidence, physical evidence, and his large brain 27 Dualism: Berzelius' grand vision 29 The quick and the dead: Friedrich Wohler's urea synthesis Oct. 2 Popularizing chemistry in the 19th century: the work of Jane Marcet 4 Radical theory: Liebig and Wohler's elegant study of the oil of bitter almonds sends chemists down a new path which eventually leads to nowhere 6, 11 Baron Justis von Liebig: opinionated and passionate superchemist, educator, entrepreneur, and probably the most famous German of his time 13 The discovery of valence: how an experiment suggested by an incorrect theory, and interpreted by using incorrect atomic weights, gave rise to a great truth 16 All coherence gone: The discovery of substitution by Laurent and Dumas destroys the Berzelian dualism and introduces type theory 18, 20 Alexander Williamson's crucial ether experiment shifts the paradigm; the reforms of August Laurent and Charles Gerhardt; mature type theory 23 Gamboling atoms: Friedrich August Kekule, the most famous chemist of the 19th century, and Archibald Scott Couper, a forgotten genius, lay the foundations of molecular structure 25 The hero of Karlsruhe: Stanislao Cannizzaro's eloquence brings order to chaos (1860) 27 Day dreams: benzene rings, and the art of drawing structures and making models 30 Type theory surrenders unconditionally: Jacobus van't Hoff and tetrahedral carbon atoms Nov. 1,3 Physical and metaphysical: wrestling with reality. The reality (or not) of atoms and molecules, positivism, Brodie's and Ostwalds alternatives to atoms 6 Brownian movement: Perrin and Einstein resolve the issue of atomic reality 8 Science as culture in the late 19th century: T. H. Huxley, Tyndall, Spencer, and scientism 10 Epilogue: the new physics changes the landscape of chemistry, and the way we view reality 13, 15 Tragedy and triumph: anesthetics and antiseptic surgery 17, 20 Chemistry in the marketplace: the accidental discovery of mauve, the first synthetic dye (1856), by 18-year-old William Henry Perkin, and his remarkable success in manufacturing and marketing it 22 The new technology: Perkin's mauve initiated a huge growth of the dye industry in England and continental Europe, especially in France 27 How the lack of support for the new industry in England and France, and the very favorable climate in Germany, caused the center of synthetic dyes to shift to Germany 29 Germany's rise to world dominance in chemical manufacturing, research, and education by the end of the 19th century Dec. 1 Dyes and disease: the beginnings of pharmaceutical chemistry 4, 6 Saint and sinner: Fritz Haber's process for the industrial synthesis of ammonia from hydrogen and nitrogen feeds the world, but it also provided the munitions that extended World War I by years, while his promotion of gas warfare made it more terrible A PREVIEW
The flavor of the course can best be given by a few images of some of the people. places, and ideas that you will meet. If you take a look at the pictures and legends on the following pages, you will have a preview of what to expect.
Sir Humphry Davy, Professor of Chemistry at the Royal Institution, chemist-poet-philosopher in the Romantic era, president of the Royal Society, founder of electrochemistry, discoverer of sodium, potassium, strontium, calcium and magnesium, and all-around genius. To boot, he was charming, handsome, powerful, rich, and a delightful lecturer. It is not surprising that he reached celebrity status in that golden age of chemistry. On the right are variations on Davy's safety lamp of 1815, which did away with coal mine explosions caused by fire damp (methane gas). Enclosing the oil flame in a wire screen keeps it from igniting the gas.
A life in chemistry. Jons Jacob Berzelius, shown here as a student at Upsala University in 1799, was destined to become one of th most celebrated scientists of his era, and an honored member of almost every learned society in Europe. The atomic weights used today are essentially his, as are the symbols for the elements and the way in which we write chemical formulas, and his love of words gave us the terms isomer, polymer, allotrope, and protein. Berzelius' devotion to chemistry won him nobility, and eventually a baroncy. On the right is his laboratory, which still remains as it was when he died in 1848. The scene is full of pathos. The aging Berzelius, his health severely compromised by a life amid toxic vapors in a nearly unventilated work space, persisted until the end, even as some of his most cherished theories were being demolished by a new generation of chemists.
Lectures in science for the general public were hugely popular in the nineteenth century. Today's culture has no direct counterpart. Here we see Michael Faraday, Fullerian Professor of Chemistry at the Royal Institution, holding forth in the institution's amphitheater, circa 1830. Faraday was an enormously talented lecture and scientist, whose achievements in the laboratory remain unsurpassed to this day.
From the sublime to the ridiculous, William Gillray's cartoon of an earlier public chemistry lecture, in 1802. Inhaling a gas has an unexpected effect upon a volunteer from the audience, while Davy gleefully pumps the bellows. Standing at the right, endowed with the notable nose, is that well-known scoundrel, American expatriate, and founder of the Royal Institution, Count Rumford. Gillray was a wonderful caricaturist and cartoonist, who particularly enjoyed tormenting George IV and the less-than-functional English royal family.
Justus von Liebig's teaching laboratory at the University of Giessen in 1840. It was the first of its kind anywhere. Baron von Liebig's innovations in teaching became the model for graduate education in Germany, and later in the United States, and played no small role in Germany's dominance in chemistry by the end of the nineteenth century. At the right is the Baron himself, that complex man, at once charming but hopelessly quarrelsome and combative. By moving chemistry from the laboratory into the public realms of medicine and agriculture (he invented chemical fertilizers), nutrition, and public health, he became the most recognized scientist of his time.
Two Liebigian artifacts. On the left is Liebig's kaliapparat of 1830, the heart of his new method for analyzing organic compounds. It revolutionized the art, and remained the standard technique for the next century. On the right is a trading card distributed with the product that made his name a household word: Liebig's Meat Extract. Motivated by his (incorrect) chemical theories and a real desire to improve nutrition, he helped found the Liebig Meat Extract Company in 1865. Based in Uruguay, the company and its successor eventually grew to 40,000 employees worldwide before it ended in 1974. Over the years, about 11,000 different cards were printed to accompany the billion or so jars of extract. The message on this particular one is clear: happy homes and Liebig's Meat Extract go hand-in-hand. By the way, these cards are still a hot trader's item; look on the internet and see for yourself.
Many of the most prominent nineteenth-century chemists, as well as other scientists, felt a sense of mission to improve the huma condition as well as the human spirit. For the first time, th public began to look to chemists for advice. London's filthy drinking water, which was pumped directly from that open sewer called the Thames River, is a case in point. The issue became particularl pressing in the Summer of the Great Stink, in 1858, when the unbearablel smell shut down Parliament. On the left, Michael Faraday serves notice to Stinky to clean up his act and remove that bloated four-legged upside-down whatever from the river. The cartoon was published in Punch, which was known then for its political satire; it later lost its edge, and went belly-up in 1992. Genuine reform of the water supply began when Sir Edward Frankland, then Professor at the Royal College of Chemistry, became London's official water analyst. Soon, by combining innovative chemistry with political acumen, he began to change public thought about what constituted clean water. The really nifty part of the story is the profound contributions that Frankland had already made to pure science: he invented organometallic chemistry and discovered valence! Frankland's portrait is on the right.
Archibald Scott Couper, the forgotten genius. Over a half century after John Dalton proposed atoms as we think of them, a great many chemists, including some of the prominent ones, still looked upon the atomic theory as merely a useful fiction. In spite of decades of research, scientists still argued not only about how to depict molecules, but whether they existed at all. Everything was chaos. Then, in 1858, there appeared a remarkable paper by Couper, who only a few years earlier had moved from linguistics to chemistry. In one stroke, he gave carbon atoms four bonds (tetravalence), connected them together in chains and drew lines to indicate connections between atoms. His most impressive depiction was glucose, shown on the right, which is essentially the same as today's version except that the number of oxygen atoms is doubled (he used the wrong atomic weight for O). Sadly for Couper, it was not he, but Friedrich August Kekule von Stradonitz, who achieved immortal fame as the pathfinder. Couper submitted his work for publication, bu it sat for a month on Adolph Wurst's desk under a pile of paper, at which point Kekule's work on the same theme was published. After a terrible row with Wurst, the embittered Couper returned to Scotland. He left chemistry forever and returned home to Scotland, while Kekule went on to become the most famous organic chemist of the century.
The intellectual wars fought over the reality of atoms persisted past the end of the nineteenth century, but the number of true believers was growing. Wooden ball-and-stick models of molecules began to appear in the mid 1860s. The first ones, shown on the left, had the correct number of bands on each atom, but the molecules were two-dimensional and flat. It was Jacobus Henricus van't Hoff who gave molecules a three-dimensional geometry in space by assuming (correctly) that a carbon atom is not only tetravalent, but also acts as if its bonds are at the vertices of a tetrahedron. The great man's own set of cardboard tetrahedral atoms, in color no less, are shown on the right.
Louis Pasteur did far more than pasteurize milk. He explained fermentation, was responsible for the germ theory of disease, and invented the first anti-bacterial vaccine (anthrax) and the first anti-viral vaccine (rabies). Here,he examines a Roux flask containing dried spinal cord for his rabies vaccine. Pasteur's undergraduate degree was in physics, and he held a doctorate in chemistry, not medicine. His first great discovery was what we now call chirality the idea that molecules can be mirror images of one another. It is the keystone of today's biochemistry. His insight came from examining mirror-image tartrate crystals, which you see on the right.
William Henry Perkin was an eighteen-year-old student at the Royal College of Chemistry when he set out during the 1856 Easter break to make synthetic quinine from coal tar. Instead of quinine, Perkin accidentally obtained the first synthetic dye, a beautiful purple color soon named mauve by fashion-conscious Parisians. A sample of that original 1856 dye is shown on the left, together with a shawl dyed with it. Perkin left the Royal College, built a factory (his parents' money) and began producing the dye less than two years after discovering it. The effort required was astonishing. Since there was no precedent for a multi-step industrial synthesis of any organic compound, he had to morph into the world's first chemical engineer. Soon, a wide variety of synthetic coal-tar dyes replaced the natural ones, which were mostly extracted from plants. Perkin's fortune was assured, but after a short time the center of the industry shifted to Germany, where it expanded into pharmaceuticals and other chemicals. German firms, and German training, dominated chemistry for decades. Many of today's giant chemical manufacturers such as BASF, Hoechst, and Bayer date from that time. Shown on the right is a small part of the BASF Ludwigshafen plant in the 1880s. That was only the beginning; the German firms eventually founded the largest cartel the world has ever seen.
A hero and a villain, all in one. In the early 1900s Fritz Haber, shown above, invented a process for reacting atmospheric nitrogen gas with hydrogen gas to make ammonia. We owe him everlasting thanks, for virtually all the nitrogen fertilizer used to grow food crops comes from the Haber process. We also owe him everlasting censure, for it was Haber who enthusiastically invented gas warfare in World War I and convinced Germany's military leaders to use it. Also shown here is part of the first Haber process plant, built for fertilizer production by BASF in less than two years and opened in September 1913, less than a year before the war started. The plant was originally built to manufacture ammonia for fertilizer, but soon after war began it was enlarged in order to convert the ammonia into nitric acid for making explosives; without it, the war probably would have ended after a year or two. It wasn't Davy's chemistry any more.
Picture credits:Davy, mauve, Gillray cartoon, Faraday lecture: Science Museum/Science and Society Picture Library. Safety lamps: National Mining Memorabilia Association. Liebig, Frankland, Berzelius, Berzelius' lab, Faraday on Thames, Couper: Edgar Fahs Smith collection. Pasteur: Labexplorer Haber: Chemical Heritage Foundation
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