Applied and Pure Science: Chemistry
Applied and Pure Science: Chemistry
Emergence from Alchemy. Many of the major scientific advances of the eighteenth century were in chemistry. Chemistry was originally the realm of alchemists, including Isaac Newton (1624-1727), who are often associated in the modern mind with the “mystical” search for the “philosopher’s stone” reputed to turn base metals to gold and to ensure immortality. Yet, modern scholars have credited these alchemist/chemists with advancing chemical knowledge and contributing to the development of modern scientific methods and equipment. By the Enlightenment, chemistry had emerged as a discipline based on rational scientific inquiry. It also had a conspicuous and direct economic benefit. The various European states, along with individual manufacturers and merchants, helped to advance the development of chemistry as a science by demanding certain products and often providing the resources for systematic investigations into their development. Many “pure” scientists joined in the quest to develop gunpowder that was more combustible and did not smoke, new colors of dyes for textiles, and bleaches that would make the production of white cloth economical. The successful research of eighteenth-century chemists cemented the growing alliance among scientists, entrepreneurs, and the state, which in turn led to even greater advances in the nineteenth century. Practical investigations associated with mining and the production of textile dyes contributed to a body of knowledge that scientists could use to help in their explanations of the universe. For example, in 1803 John Dalton (1766-1844), a schoolteacher in Manchester, England, proposed a doctrine he called “atomism,” basing his theory on the findings of French chemists Antoine-Laurent Lavoisier (1743-1794), Claude-Louis Berthollet (1748-1822), and Jean-Antoine Chaptal (1756-1832). Dalton’s atomism was the beginning of modern atomic theory.
Atomism. Experimentation with gases convinced Dalton that elements were made up of “atoms,” which he defined as indivisible, and that substances were madeup of varying proportions of elements. He devised a new system of chemical notation in equations (as in H2O) and formulated physical laws to describe the ratios. Although atomism was accepted only slowly, by the middle of the nineteenth century it had revolutionized chemistry and transformed how Western cultures looked at the physical world. After decades of research into the relationship of gases and combustion, in 1774 English clergyman Joseph Priestley (1733-1804) identified a substance that became known as oxygen. Priestley figured out that in sunlight green plants use carbon dioxide and produce oxygen. He also ascertained that combustion in air results from oxidation; for example, he recognized that in fires the substance that burns is oxygen. Lavoisier expanded on Priestley’s breakthrough, giving oxygen its name and realizing that all chemical reactions may be placed in a rational system composed of elements. According to Lavoisier, there were three basic chemical compounds: acids comprise oxygen plus nonmetals; bases are oxygen plus metals; and salts are acids plus bases. This new system of chemical taxonomy paved the way for vast practical advances at the end of the eighteenth century. Russian chemist Dmitry Ivanovich Mendeleyev (1834-1907) built on Lavoisier’s work by creating the modern periodic table of the elements in 1869. After identifying substances in the eighteenth century, chemists of the nineteenth century began to comprehend their structures. The insights of Priestley, Lavoisier, and other chemists of the early Industrial era laid the foundations for chemical research into plants and animals at the molecular level, marking the beginning of organic chemistry. Undertaken in Paris by Lavoisier’s successors and in the German-speaking world by Justus von Liebig (1803-1873), such research required a careful, systematic approach. Liebig established the model for the modern research laboratory at Giessen in 1825. His “hands-on” approach to teaching and his search for productive uses of scientific advances rapidly spread to other German universities and research centers. German predominance in European chemical research led to an economic advantage later in the century.
New Approaches. The findings of French and German chemists, including Louis Pasteur (1822-1895), revealed that to understand the nature of a molecule it is not enough to ascertain its chemical formula, which indicates only the kinds and numbers of atoms in that molecule. It is also necessary to discover the structure of a molecule, that is, to understand how its atoms are linked. Having discovered how to determine the configuration of molecules, chemists developed the ability to substitute atoms and transform one substance into another. In 1870 there were about fifteen thousand known organic compounds; by 1910 there were one hundred fifty thousand. The first practical application of the new science of organic chemistry was the discovery of synthetic dyes. In 1856 Englishman William Henry Perkin discovered how to fabricate the first artificial dye. Made from coal tar, a residue of the gas industry, Perkin’s aniline dyes were embraced by the German textile industry, whose scientists developed more than one thousand different synthetic dyes before 1914. German synthetic dyes were so popular that they drove natural colorings from the market, and dye prices fell by two-thirds. In 1913 Germany manufactured 90 percent of the dyes used worldwide. By making Germany the major manufacturer of lucrative synthetic dyes, German chemists formed such close ties with industry that they were able to attract the financial and institutional support for other sorts of research, which yielded dramatic new dividends.
J. D. Bernal, The Scientific and Industrial Revolutions, volume 2 of Science in History, third edition (Cambridge, Mass.: MIT Press, 1971).
Eric Dorn Brose, Technology and Science in the Industrializing Nations, 1500-1914 (Atlantic Highlands, N.J.: Humanities Press, 1998).
Charles Coulston Gillispie, Science and Polity in France at the End of the Old Regime (Princeton: Princeton University Press, 1980).
Mary Jo Nye, Before Big Science: The Pursuit of Modern Chemistry and Physics, 1800-1940 (Cambridge, Mass.: Harvard University Press, 1996).