The Emergence of Swedish Chemists during the Eighteenth Century

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The Emergence of Swedish Chemists during the Eighteenth Century

Overview

Despite Sweden being one of the largest countries in Europe, extending northward into the Arctic Circle and for a time including most of Finland, its achievements in science somehow escape attention. Yet from the beginning of the eighteenth century, the belief that scientific methods could help to improve mining, metallurgy, and agriculture was a spur to the development of Swedish chemistry. A substantial innovation came in the form of the blowpipe, which was introduced in 1738 and made it possible to increase the heat of a flame. Applying the heated flame to a mineral revealed information about the mineral's nature and composition. Swedish chemists also concentrated their efforts on pharmacy and the applications of chemistry to medicine.

Background

Georg Brandt (1694-1768) inherited his interest in chemistry and metallurgy from his father, a mine owner and former pharmacist. Brandt began his studies at Uppsala University. He went abroad to study chemistry and medicine, and on his way back to Sweden trained in the Hartz mountains in mining and smelting. On his arrival home he was made director of the chemical laboratory of the Council of Mines. Brandt's professional life was multifaceted: in addition to being an able administrator and teacher, he was also an expert chemical experimenter. He was the first to establish the metallic nature of arsenic, but his discovery of cobalt is the work for which he is best known. In 1751 he proved that the brittleness of iron when hot is due to its sulfur content.

Johan Gottschalk Wallerius (1709-1785) was instrumental in opening new avenues for the practical application of chemistry. Born into a family of clergymen, Wallerius studied astronomy and mathematics before turning to medicine. He was employed on the medical faculty first at the University of Lund (where he had only three students) and then at the University of Uppsala. His lectures at Uppsala covered medicine, physiology, and materia medica and were attended by students of both medicine and mining science. In addition to his stated duties, Wallerius set up a private chemical laboratory so he could do experiments and lecture in chemistry and mineralogy. In 1750 he was appointed to a professorship in chemistry, metallurgy, and pharmacy at the University of Uppsala, the first of its kind in Sweden. With this new respectability, he succeeded in getting the university to fund a chemical laboratory, which was completed in 1754. A book he published in 1761 on the chemical foundations of agriculture was the most widely used textbook on the subject. Failing health forced his retirement, in 1767, to his farm south of Uppsala, where he continued his scientific writing.

The leading eighteenth-century Swedish chemist was Torbern Bergman (1735-1784), who achieved an international reputation for his skill as a chemical analyst and his studies of attraction between chemicals. When Bergman's health began to fail in 1770, he was advised to drink foreign mineral waters. But these waters were expensive and often arrived in Sweden in poor condition. Bergman decided to study the composition of the waters with the aim of preparing similar mixtures locally. Although his results were not very accurate, his guiding principles were sound and led to the law of equivalent proportions formulated by German chemist J. B. Richter (b. 1762) in the 1790s. Another problem that interested Bergman was how one element in a compound could be displaced by another. He reasoned that such changes must be due to a difference in the attractive forces between the elements (he called these attractive forces "affinities"). His work in this area was an important step in understanding how chemicals combine.

In 1770, Bergman met Karl Wilhelm Scheele (1742-1786), an apothecary's assistant who impressed Bergman with his knowledge of chemistry. Bergman suggested that the younger man study the properties of a recently discovered ore called pyrolusite. Scheele's investigations led to the discovery of chlorine, which was announced in 1773 and revolutionized the textile bleaching process in early industrial England. On heating pyrolusite, Scheele found that it gave off a green choking gas that attacked virtually any matter. Scheele also made observations regarding the formation of soda that suggested new ways of making soda for glass or soap manufacture. Between 1770 and 1773, Scheele discovered what he called fire air, which we know as oxygen, and which he described as colorless, odorless, and tasteless. Although his discovery was significant, his adherence to the phlogiston theory prevented him from understanding the role of oxygen in combustion, later clarified by Antoine Laurent Lavoisier (1743-1794) in France. Scheele questioned the theory, but he did not abandon it. Oxygen theory was not published in Sweden until 1778.

Johann Gottlieb Gahn (1745-1818) studied physics and chemistry at Uppsala and became Torbern Bergman's laboratory assistant there in 1767. Gahn later took up a position at the College of Mining, where he worked on improving the processes used in copper smelting at a local mine. Gahn carried out his experiments in a laboratory that he installed in his own garden and paid for himself. Gahn published almost nothing, but knowledge of his expertise traveled far, and he was much in demand. Gahn collaborated with both Scheele and Bergman, and he was responsible for introducing Scheele to Bergman. Bergman was generous in crediting Gahn with extracting manganese from pyrolusite in 1774. Bergman had doubted that the mineral contained any metal. Although Scheele reigned supreme as a chemical experimenter, no one surpassed Gahn in blowpipe analysis. Gahn's blowpipe experiments with inorganic substances in animal bones led later to Scheele's method of obtaining phosphorus from animal bones.

Peter Jacob Hjelm (1746-1813) was educated at the University of Uppsala and in 1794 was appointed chemical director of the Swedish bureau of mines. Following work laid earlier by Scheele, in 1782, Hjelm heated a paste prepared from molybdic oxide and linseed oil at high temperatures in a crucible and became the first person to produce pure metallic molybdenum. The first practical application of the metal, however, would await World War I, when a shortage of tungsten provoked its use in the manufacture of arms.

Impact

Science in Sweden both represents some of the most important advances in the field and serves as an example of how ideas develop under unusual conditions. Although a Catholic country during the Middle Ages, Sweden emerged from the Protestant Reformation firmly committed to Lutheranism. This unity in religion was a major influence on the development of science in Sweden.

The backdrop for scientific exploration in Sweden was the University of Uppsala, one of the oldest universities in Scandinavia. By 1620 it had become a major seat of learning, with professors imported from Germany. Progress in science, however, was inhibited by a stubborn adherence to the Aristotelian view of the universe, which centered on the idea of an immobile Earth. As more and more Aristotelians came to fill chairs at the university, new thinking was stifled. Moreover, an alliance formed between Aristotelianism and the Lutheran faith, which further cemented the influence of established views.

The teachings of the French philosopher René Descartes (1596-1650), though a late arrival to Sweden, opened the way for new scientific ideas from the south, and along with them the introduction of scientific instruments such as the air pump, the thermometer, and the barometer. The end of absolute monarchy in 1718 likewise signaled an age of democracy that fostered the rise of science. Because the policies of the University of Uppsala were subject to government interference, the university was required to provide training in physics and chemistry for civil service degrees. As a result, the first university appointments in science were established.

Further evidence of a changing climate in Sweden was the formation of other centers of science, for example, the Royal Society of Science at Uppsala, first convened in 1710 as a "College of the Curious" in response to the plague. Among the luminaries who served as secretaries were Anders Celsius (1701-1744) and Carolus Linnaeus (1707-1778). In 1739, a national academy of science was established to promote the "useful sciences" that came to include all the well-known names in Swedish science, for example, Emanuel Swedenborg (1866-1772), Cronstedt, Bergman, and Scheele. Today the Royal Swedish Academy of Sciences awards and administers the Nobel Prizes in chemistry and physics.

The importance of Swedish chemistry in the eighteenth century is undisputed, and remarkable considering that modern science was not accepted in the country until almost the end of the 1700s. Forty percent of the chemical elements found since the Middle Ages were discovered in Sweden, among them cobalt, nickel, oxygen, chlorine, lithium, and manganese. Discoveries were also made of nonelementary substances such as formic acid, a substance found in the bodies of red ants and used in dyeing textiles, and the chemical nature of many minerals was elucidated.

Swedish investigations into chemistry were as hazardous to their practitioners as they were impressive: the process of determining the properties of unknown substances required chemists to touch, breathe in, and taste a wealth of toxic materials. Bergman and Scheele both died young. Central to Sweden's success in chemistry were its vast mineral resources—a virtually unlimited store of materials to investigate—an emphasis on careful measurement, and the innovation of the blowpipe for use in experiments.

GISELLE WEISS