Benjamin Franklin

    Tell me and I forget. Teach me and I remember. Involve me and I learn. -Benjamin Franklin 

           His discoveries resulted from his investigations of electricity. Franklin proposed that "vitreous" and "resinous" electricity were not different types of "electrical fluid" (as electricity was called then), but the same electrical fluid under different pressures. He was the first to label them as positive and negative respectively, and he was the first to discover the principle of conservation of charge.

In 1750 he published a proposal for an experiment to prove that lightning is electricity by flying a kite in a storm that appeared capable of becoming a lightning storm. On May 10, 1752 Thomas-François Dalibard of France conducted Franklin's experiment using a 40-foot (12 m)-tall iron rod instead of a kite, and he extracted electrical sparks from a cloud. On June 15 Franklin may possibly have conducted his famous kite experiment in Philadelphia, successfully extracting sparks from a cloud. Franklin's experiment was not written up with credit until Joseph Priestley's 1767 History and Present Status of Electricity; the evidence shows that Franklin was insulated (not in a conducting path, where he would have been in danger of electrocution). Others, such as Prof. Georg Wilhelm Richmann were indeed electrocuted during the months following Franklin's experiment.