Before about the last quarter of the eighteenth century, electricity essentially did not exist as a comprehensible phenomenon. The effects of lightning were of course universally known, but no remotely accurate guesses had been made as to its causes. The phenomenon of static electricity was also known--the word electric and its variations comes from the Greek word elektron (in Latin, electrum), or amber, which produces static electricity when rubbed with a cloth (Shilling, 1948, p. 5). (confusing, the term was also used for an alloy of gold and silver, perhaps of similar color.) Experimentation with static electricity began in sixteenth-century Italy; Jerome Cardan, about 1550, first distinguished electrical from magnetic phenomena (Roller and Roller, 1954, p. 5). The relationship between the two continued to be acknowledged; Gilbert, in 1600, included a section on electrical phenomena in his work on magnetism (Roller and Roller, 1954, pp. 5-13).
Little progress in the understanding of electricity was made, however, during the succeeding century and a half of scientific development. One reason, perhaps, was that electrical phenomena were uncertain and perplexing. A number of basic misapprehensions regarding electricity, for example the belief that dry air and humid air had different conductivities, persisted for a very long time. Another reason was simply that electricity appeared to be a distinctly minor phenomenon, a weak property of a few substances. It seemed to have neither practical applications in and of itself, nor to hold any keys to the understanding of more important phenomena.
The Leyden jar, or primitive capacator, the first known means of storing a significant electric potential, was discovered in 1745--quite by accident, as the proper means of preparing one contradicted existing theories, such as they were (Heilbron, 1979, p. 309). But not until the subsequent investigations of Benjamin Franklin di...