Svante August Arrhenius was born in Uppsala, Sweden, on February 19, 1859. His intelligence and creativity were apparent from an early age–he taught himself to read when he was three. Although credited with many scientific innovations, he remains best known for his ionic theory of solutions, for which he was awarded the Nobel Prize in chemistry in 1903. Arrhenius died in Stockholm on October 2, 1927.
Science is a human endeavor subject to human frailties and governed by personalities, politics, and prejudices. One of the best illustrations of the often bumpy path of the advancement of scientific knowledge is the story of the Swedish chemist Svante Arrhenius. When Arrhenius began his doctorate at the University of Uppsala around 1880, he chose to study the passage of electricity through solutions.
This was a problem that had baffled scientists for a century. The first experiments had been done in the 1770s by Cavendish, who compared the conductivity of salt solutions with that of rainwater, using his own physiological reaction to the electric shocks he received! Arrhenius had an array of instruments to measure electric current, but the process of carefully weighing, measuring, and recording data from a multitude of experiments was a tedious one. After his long series of experiments were performed, Arrhenius quit his laboratory bench and returned to his country home to try to formulate a model that could account for his data. He wrote, “I got the idea in the night of the 17th of May in the year 1883, and I could not sleep that night until I had worked through the whole problem.” His idea was that ions were responsible for conducting electricity through a solution. Back at Uppsala, Arrhenius took his doctoral dissertation containing the new theory to his advisor, Professor Cleve, an eminent chemist and the discoverer of the elements holmium and thulium. Cleve’s uninterested response was what Arrhenius had expected.
It was in keeping with Cleve’s resistance to new ideas; he had not even accepted Mendeleev’s periodic table, introduced ten years earlier. It is a longstanding custom that before a doctoral degree is granted, the dissertation must be defended before a panel of professors. Although this procedure is still followed at most universities today, the problems are usually worked out in private with the evaluating professors before the actual defense. However, when Arrhenius did it, the dissertation defense was an open debate, which could be rancorous and humiliating. Knowing that it would be unwise to antagonize his professors, Arrhenius downplayed his convictions about his new theory as he defended his dissertation. His diplomacy paid off: he was awarded his degree, albeit reluctantly, as the professors still did not believe his model and considered him to be a marginal scientist, at best.
Such a setback could have ended his scientific career, but Arrhenius was a crusader; he was determined to see his theory triumph. Recognizing his low credibility in his home country, he sent his dissertation first to Rudolf Clausius, a German scientist who had formulated the second law of thermodynamics, but Clausius wasn’t interested. He next approached Lothar Meyer, another German scientist who had gained prominence for his work on the periodicity of the elements, but Meyer was also unresponsive. Finally, Arrhenius found the right champion in Wilhelm Ostwald, a German professor of chemistry at Riga. Ostwald, already known as a defender of revolutionary chemical causes, fully accepted the idea that reactions in solution often involve ions. In 1885, Arrhenius began working in Ostwald’s laboratory, continuing his research on ions.
Reading everything he could find on the subject, he came across a research paper written by a Dutch scientist, Jacobus van ‘t Hoff, which was particularly helpful in placing the ionic theory on firmer ground. In 1887, Arrhenius went to Amsterdam to meet van ‘t Hoff. At 22 years of age, van ‘t Hoff had postulated the existence of stereochemistry; that is, that atoms in molecules have definite relative positions in space. This theory was initially criticized harshly, and van ‘t Hoff, aided by Ostwald, had to fight to have it accepted. The ionic theory was yet another unaccepted theory for which both Ostwald and van ‘t Hoff would extend their support. By the time Arrhenius returned from Amsterdam, Ostwald had moved to Leipzig, where he had become professor of chemistry.
It was there that Ostwald and Arrhenius put together a promotional strategy that would have done credit to a canny politician. In the then-new journal Zeitschrift fur Physikalische Chemie, Ostwald wrote about the ionic theory, and finally, the European scientific establishment began to listen. Arrhenius’s classic paper “On the Dissociation of Substances in Aqueous Solutions” was published in 1887. The ionic theory had become one of the most controversial issues in science.
Although Ostwald, van ‘t Hoff, and Arrhenius continued to champion the cause vigorously, many scientists remained vehemently opposed to the theory. In fact, even though Arrhenius was by then a prominent scientist, his appointment as Professor of Chemistry at the University of Stockholm was highly controversial. Ultimately, the ionic theory triumphed. Arrhenius’s fame spread, and honors were heaped on him, culminating in the Nobel Prize in chemistry.
Not one to rest on his laurels, Arrhenius turned to new fields, including astronomy. He formulated a new theory that the solar system may have come into being through the collision of stars. His exceptional versatility led him to study the use of serums to fight disease, energy resources, and conservation, and the origin of life.
