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Electric eels
In 1800, electric eels were first captured for scientific study by Alexander von Humboldt with Aimé Bonpland from a river in the jungles of South America. Electrophorus Electricus is a large eel-like fish and one of several species which are capable of generating electricity by contraction of their muscles. They use this for navigation, as defence mechanism and as a means of killing prey. The eel can deliver a shock of up to 500 volts. During their scientific investigation of the behaviour of the eels, the scientists received massive electric shocks.

Electron
In 1897, at the Royal Institution Friday Evening Discourse, Joseph John Thomson (1856-1940) first announced the existence of electrons (as they are now named). Thomson announced to the assembled Academy that earlier in the year, he had made a surprising discovery. He had found a particle of matter a thousand times smaller than the atom. He called it a corpuscle, meaning "small body." Although Thomson was director of the Cavendish Laboratory at the University of Cambridge, and one of the most respected scientists in Great Britain, the scientists present found the news hard to believe. The received opinion at the time was that the atom was the smallest and indivisible part of matter that could exist. Thompson however, had demonstrated that

atoms are not indivisible for negatively electrified particles can be torn from them by the action of electrical forces.

Equivalent Heat
Robert Mayer was a German physicist. While serving as ship's doctor on a trip to Java, he considered the physics of animal heat. In 1842, he calculated the mechanical equivalent of heat, from an experiment which compared the work done by a horse powering a mechanism which stirred paper pulp in a cauldron with the rise in the temperature of the pulp. He also argued that solar energy was the ultimate source of all energy on earth, both living and nonliving. More than that, Mayer developed the idea of the conservation of energy before either Joule or Helmholtz published their papers on the subject. The prominence of the latter two however, ensured that Mayer never received proper recognition for his insights.

Ole Evinrude
Evintrude (1877-1934) was a Norwegian inventor and manufacturer of the outboard marine engine. He was rowing his small boat one day intending to have a picnic on a small island some distance offshore. By the time he reached his picnic spot he had concluded that rowing was more difficult than it needed to be for his simple purpose. He resolved then and there to invent a means of moving small boats quickly and easily through the water. He went ahead and by 1909 he had invented the first practical outboard motor. He patented it in 1910 and it very quickly replaced steam and foot-driven motors on small boats. He went on to develop a new industry and eventually came up with the standard Evinrude Outboard Motor that remains popular to this day.

Exclusion Principle
In 1925, Wolfgang Pauli published his "exclusion principle." At the age of 24 he introduced the idea that two nearby electrons cannot be in exactly the same quantum state at the same time. For this, now fundamental, contribution to quantum mechanics, he was awarded a Nobel Prize in 1945.

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