Science and Celebrity: Humphry Davy’s Rising Star

Davy using a voltaic battery to experiment with the decomposition of alkalis. Bettmann Archives.

By T. K. Kenyon

The June air was stifling. But in the Royal Society’s steeply raked amphitheater London’s fashionable men and women, scientists and laymen, crowded the benches and gallery to watch Humphry Davy, the celebrity chemist, present his latest scientific findings. The previous year at the Royal Society’s prestigious Bakerian Prize lecture, Davy had tossed a nugget of metallic potassium into a flask of water, where the lump skittered around the surface of the water before exploding in lavender flames. Expectations for the June lecture were high. The crowd leaned in, anticipating another colorful, if not explosive, performance. With his lively demonstration of electrolysis using a sizable voltaic pile, Davy did not disappoint.

The year 1808 was an important one for Humphry Davy. In that year two centuries ago, Davy discovered five elements: barium, calcium, boron, strontium, and magnesium. He delivered the news of his discoveries to rapt audiences in two captivating lectures—the first in June and another in December—that marked stepping stones in his climb to an apex of scientific and social celebrity status in London. But while Davy enjoyed his celebrity, he also bore gossip, speculation, and criticism as an outsider.

Davy’s 1808 discoveries depended on his use of and research into the burgeoning field of electrochemistry, the study of electricity’s effect on chemical reactions. As a young researcher at the Bristol Pneumatic Institute, Davy had caught the fever of excitement over Count Alessandro Volta’s 1800 paper describing what came to be known as the voltaic pile, a sandwich of a damp cardboard disk between two metal disks that generated a weak but continuous charge. Young Davy immediately began to study and experiment with voltaic piles, making batteries out of them, and using the electrical charges to separate elements from their compounds. Davy had contributed to the field by discovering that electricity itself was caused by chemistry. By the time he arrived in London in 1801, Davy had written six papers on his experiments in electrochemistry. In 1807, using electrochemistry, Davy isolated the metals potassium (from caustic potash, now known to be potassium hydroxide [KOH]) and sodium (from caustic soda, now known to be sodium hydroxide [NaOH]). In 1808 he isolated four of the alkaline earth metals from several mineral mixtures.

Davy’s electrolytic apparatus was simple in concept: a battery was connected to metallic electrodes that were dipped into a liquid containing the compound that Davy wanted to decompose into its elements. At first, Davy tried to dissolve various compounds in water, but the water was electrolyzed into hydrogen and oxygen, leaving the investigational compound intact. So Davy melted the minerals he was studying and then alloyed them with mercury before passing the electric current through them. The molten compounds bubbled when the current passed through, producing small clumps of silvery metals on one electrode and liberating gaseous oxygen on the other. The electrodes themselves were inert and did not react chemically with the electrolyte. Davy extracted pure barium from a substance called “baryte,” which may have been barium oxide (BaO) or barium sulfate (BaSO4). From “lime,” or calcium oxide (CaO), also known as quicklime, he prepared calcium. To isolate strontium he used “strontites,” which may have been a pure strontium oxide (SrO) or the strontium ore from the Strontian region of Scotland, composed primarily of strontium sulfate (SrSO4). Davy’s magnesium was isolated “magnesia,” or magnesium oxide (MgO).

Experiments as Entertainment

The late 1700s had witnessed the birth of the public scientific lecture, and by 1808 it had become a popular source of entertainment for London’s middle class and elite. Curious men and women would flock to lecture halls to watch as scientists demonstrated the latest discoveries about the properties of electricity, chemical elements, air, and gases. The demonstrations produced sparks, explosions, and unusual odors, all guaranteed to excite the audience. Davy was an expert at public demonstrations, showing off his own extra-ordinary discoveries and a flare for the theatrical that kept his audience riveted to their seats—and kept them talking about him long after they’d left the lecture hall.

For his June 1808 lecture Davy carted one of the Royal Institution’s enormous 600-plate voltaic batteries into the hall to demonstrate electrochemistry for the crowd. Stored in flasks, the molten fluid shimmered in the sunlight, and when the battery was connected to the electrolytic cell, the sudden appearance of metal electroplating one electrode and oxygen effervescing from the other must have seemed like magic.

Ladies in the audience twittered at Davy’s fireworks and surreptitiously took notes. Aristocrats preened and even took turns standing in as Davy’s assistant. He was revered by the audience as a scientific wunderkind. Davy was at the top of his game.

But there was another element to his celebrity. Davy was an unlikely star of the Regency period. His humble country beginnings, some early scientific missteps, and a youthful association with political radicals made his London celebrity and aristocratic patronage suspect. He was perceived by some London conservatives as a pretentious social climber, who turned his back on early loyalties in order to curry favor with the Royal Society’s elite. Davy wore rustic clothing, pitched his theatrics toward the women in his audience, and seemed to aspire to a social class to which he did not belong; all this earned him the label of a dandy and a fop. And while the general public revered him for his scientific accomplishments, he was often criticized by the aristocratic and scientific elite.

A self-starting student

Most scientists of the age were formally educated men of independent wealth. Antoine-Laurent Lavoisier, whose chemistry textbook inspired many of Davy’s early experiments, was a wealthy French nobleman who attended the Collège Mazarin and the University of Paris. Joseph Banks, who served as president of the Royal Society when Davy presented most of his Bakerian lectures, was born into a wealthy family, owned country estates and lavish town houses, and attended Eton, Oxford, and Christ Church, where he privately paid honoraria for lecturers with whom he wished to study. In contrast Davy’s parents, though from respectable families, were middle-class, and his cobbled-together education, first in Penzance and later in Bristol, was rather informal.