Experimenting independently in different countries, Ewald Georg von Kleist and Pieter van Musschenbroek invented the Leyden jar, the first device that could accumulate and store large amounts of electric energy. Later called a condenser or capacitor, the Leyden jar could conserve an electric charge for future use or experimentation.

Significant experimentation with electricity began after 1660, when Otto von Guericke Guericke, Otto von of Magdeburg, Germany, invented the first electrical machine, Machines;and electricity[electricity] which generated electricity by friction. In 1675, using an improved machine with a glass globe, Sir Isaac Newton Newton, Sir Isaac
Newton, Sir Isaac;electricity studied sparking, attraction, and repulsion. In 1729, Stephen Gray [p]Gray, Stephen established the important principle that electricity could travel or be transmitted, and he was the first to differentiate between materials that were insulators or nonconductors (such as silk filaments) and conductors (such as metal or water). [kw]Invention of the Leyden Jar (Oct., 1745, and Jan., 1746)
[kw]Jar, Invention of the Leyden (Oct., 1745, and Jan., 1746)
[kw]Leyden Jar, Invention of the (Oct., 1745, and Jan., 1746)
Electricity;storage of
Leyden jar
[g]Germany;Oct., 1745, and Jan., 1746: Invention of the Leyden Jar[1140]
[g]Netherlands;Oct., 1745, and Jan., 1746: Invention of the Leyden Jar[1140]
[c]Inventions;Oct., 1745, and Jan., 1746: Invention of the Leyden Jar[1140]
[c]Science and technology;Oct., 1745, and Jan., 1746: Invention of the Leyden Jar[1140]
Kleist, Ewald Georg von
Musschenbroek, Pieter van
Nollet, Jean-Antoine
Watson, William
Franklin, Benjamin
[p]Franklin, Benjamin;electricity

By the early 1740’s, amateurs and philosophers, as well as scientists, were performing electrical experiments and demonstrations, often for entertainment. For instance, a popular pastime was igniting combustibles such as gunpowder and alcohol by sparks from an electrical friction machine. However, experimenters still needed a way to accumulate and store electricity. The solution was the Leyden jar, invented independently by Ewald Georg von Kleist in October, 1745, and by Pieter van Musschenbroek in January, 1746.

Von Kleist was a German scientist and cleric who had become interested in electricity while studying at the University of Leyden in the 1720’s. Later, he learned about the experiments of University of Leipzig professor Georg Mathias Bose, Bose, Georg Mathias who experimented with electrical flares and sparks from water in an electrified glass vessel. Von Kleist began experimenting with his own electric generator with the goal of creating stronger flares or sparks.

In October, 1745, von Kleist accidentally invented the first condenser. Electrical conductivity He had set up a medicine bottle (a nonconductor) filled with fluid (a conductor), and inserted a nail in the cork stopper. One end of a metal wire was connected to his electrical machine’s prime conductor, and the other end was placed inside the jar of fluid. While holding the jar in one hand, von Kleist connected the nail to the electric generator and electrified the nail. Touching the nail with the other hand, he received a severe shock, and the charged nail also produced sparks when it touched another object. It was then obvious to von Kleist that the nail and the jar had temporarily stored electricity. In November, he wrote letters about his invention to other scientists, but none of them could successfully replicate von Kleist’s experiment before the news broke about van Musschenbroek’s similar experiment in January, 1746.

Van Musschenbroek was a Dutch professor, medical doctor, mathematician, and scientific instrument maker, who, in 1729, was the first person to use the term “physics” Physics as a term to name what had previously called natural philosophy. Independently of von Kleist, van Musschenbroek, along with Jean Allamand Allamand, Jean of the University of Leyden and an assistant, Andreas Cunaeus, conducted the same experiment as von Kleist. However, unlike von Kleist, van Musschenbroek realized that the hand holding the jar served as a conductor and that the bottle’s exterior had to be grounded (held by a person standing on the ground) when electrifying the nail or wire.

In January, 1746, van Musschenbroek announced his invention, and in April, 1746, his discovery was presented to the Académie des Sciences (Academy of Sciences) Academy of Sciences, France in Paris. Van Musschenbroek was able not only to develop a working model of the condenser but also to explain the device sufficiently to allow other scientists to repeat his experiement. He was therefore credited with its invention, and the device came to be known as a Leyden jar, since it was invented at the University of Leyden.

The news of the Leyden jar spread rapidly, first in Europe and then throughout the world. Electricity became more popular than ever. Even nonscientists became “electricians,” performing various kinds of sensational new demonstrations. Frequently, exhibitions Animal experimentation resulted in animals and birds being killed by electrical shock. Longer and more powerful sparks became possible with Leyden jars built into frictional static-generating machines. Some of the most elaborate and memorable demonstrations were experiments by Jean-Antoine Nollet, a French physicist, member of the Académie des Sciences, and abbot of the Grand Convent of the Carthusians in Paris. It was Nollet who coined the term “Leyden jar.” Moreover, in 1745, Nollet developed a theory that electricity could travel long distances quickly, based on attraction and repulsion in a continuous flow of electrical matter between charged bodies.

Combining scientific research with spectacular effects, Nollet helped popularize electrical phenomena. At Versailles in 1746, for instance, Nollet impressed King Louis XV by sending a discharge or current from a Leyden jar through a long chain of 180 royal guards connected by pieces of wire. The discharge caused all of the soldiers to leap into the air simultaneously when the circuit was completed. Louis XV was so entertained that he requested a second demonstration be performed in Paris. Consequently, Nollet repeated the procedure with a single row of 700 monks holding hands. When the Leyden jar was discharged, all the monks jumped simultaneously into the air.

The Leyden jar also stimulated serious scientific research. Within a year of its invention, the English apothecary, scientist, and physician William Watson created an improved Leyden jar coated with metal foil on both the inside and outside. The metal foil on the outside served the purpose of the hand holding the jar in the earlier experiments. Watson attempted to devise an accurate test for measuring the velocity of electricity. In 1747, he laid out a wire circuit 12,276 feet long across the River Thames at Westminster Bridge. He then discharged an electric spark from a Leyden jar through the wire. Transmission occurred immediately, so Watson determined that the velocity of electricity was instantaneous.

In the United States, Benjamin Franklin conducted experiments using the Leyden jar. He proved that the electrical charge was stored in the glass rather than the water, as had generally been thought, and that the basis of the jar’s electrostatic activity was the insulating material around the conductor. After wrapping both the inside and outside of a glass jar with lead foil and electrifying the jar, Franklin removed the wrappings and discovered that each sheet had been charged. As a result, the device was called a “condenser.” In 1752, Franklin collected electrical charge in a Leyden jar during his famous experiment flying a kite in a lightning storm.

With the invention of the Leyden jar, scientists finally had a device that could generate and store large quantities of electrical charge for later use. Thus, the invention was crucial for future advancements in electrical research. The Leyden jar further popularized electricity, as even nobility and royalty were drawn to the dramatic demonstrations it made possible.

The Leyden jar also marked a turning point in the field of electrotherapy, Electrotherapy
Medicine;and electricity[electricity] or the therapeutic use of electricity. Since about 400 b.c.e., electrical shocks from torpedo fish had been used to treat pain, gout, and other illnesses. Christian Gottlieb Kratzenstein Kratzenstein, Christian Gottlieb (1723-1795) was possibly the first physician to use the Leyden jar to treat diseases. By 1752, there were forty published medical applications of electricity, and by 1789 there were seventy published uses. There were reports of successful treatment of disorders such as paralysis, epilepsy, angina pectoris, kidney stones, and sciatica. Beginning in the late 1760’s, hospitals began installing electric shock machines. However, interest in electrotherapy declined toward the end of the nineteenth century.

Most significantly, the Leyden jar was the first condenser and the forerunner of modern capacitors, devices that contain two conductors separated by an insulator. In the twenty-first century, capacitors come in all sizes, including microscopic ones that are part of integrated electric circuits. The devices store electricity and are used in electric power systems, radios, televisions, computers, and various kinds of electronic equipment.

• Bernal, J. D. A History of Classical Physics from Antiquity to the Quantum. New York: Barnes & Noble Books, 1997. Includes sections on Benjamin Franklin’s Leyden jar experiments and a discussion and illustration of van Musschenbroek’s experiment. Illustrations and index.
• Ford, R. A. Homemade Lightning: Creative Experiments in Electricity. New York: McGraw-Hill, 2002. A chapter on the Leyden jar condenser describes the early jars and includes instructions for creating Leyden jars. Illustrated, with an appendix, a bibliography, and an index.
• Heilbron, J. L. Electricity in the Seventeenth and Eighteenth Centuries: A Study in Early Modern Physics. Mineola, N.Y.: Dover, 1999. This significant and scholarly work provides detailed chapters on the invention of the Leyden jar and Benjamin Franklin’s experiments. Illustrated. Index and extensive bibliography.
• Schiffer, Michael B. Draw the Lightning Down: Benjamin Franklin and Electrical Technology in the Age of Enlightenment. Berkeley: University of California Press, 2003. This story of Franklin and eighteenth century electrical technology discusses the Leyden jar extensively. Illustrated. Bibliography and index.
• Whittaker, E. T. A History of the Theories of Aether and Electricity. New York: Tomash, 1987. This general history includes sections about the work of van Musschenbroek and Watson. Illustrated. Bibliography and index.

Gray Discovers Principles of Electric Conductivity

Du Fay Discovers Two Kinds of Electric Charge

Nollet Discovers Osmosis

Franklin Demonstrates the Electrical Nature of Lightning

Aepinus Publishes Essay on the Theory of Electricity and Magnetism

Volta Invents the Battery

Benjamin Franklin; Louis XV. Electricity;storage of
Leyden jar