Why history has forgotten the man who discovered protons and electrons

Today we have positive and negative charges in an orderly binary system. We owe that orderliness to its original discoverer — Charles Du Fay. If he hadn't stepped in, we might have been calling charges by their colors.

Charles Du Fay was a scientist in the early 1700s, when people were first playing with electricity in a modern scientific way. The research was so basic that no one even had the words to describe the phenomenon. People noticed that when specific materials were rubbed, they seemed to attract other materials, but few could classify what was happening or why it occurred. At the time, it was widely believed that things that were the same color produced the same type of electricity. Scientists had noticed that adding dye to a substance often changed the properties of the charge, and color was presumed to be the cause. Well before the colors and flavors of quarks, we had color forces in electricity.


Du Fay conducted some investigations into the nature of electricity and published "A Discourse Concerning Electricity." In this paper, he outlines most of the basic facts that we know about electricity — he came up with the basic process of charging objects (heating and rubbing) and he showed that there are conductors and insulators of electricity. He also noticed that things tended to conduct electricity better when they were wet.

Most importantly, he was the first to disprove the color theory, showing that like colors can produce unlike charges. He admitted that dyes can change the electric force of objects, but noted that those dyes also change the chemical composition. Painstakingly, he showed that objects of exactly the same color can produce different charges. Though he took away one system for organizing charge, he came up with a better one; instead of colors producing a rainbow of charges, he showed that only two different general types of charge were possible. Du Fay wrote that there were two kinds of "fluids" of electricity. There was a "vitreous" fluid, generally produced by glass or gems., and also a resinous fluid produced by things like paper, amber, or silk. Like fluids repelled each other, and unlike fluids attracted each other.

As you've noticed, Du Fay came up with the binary system but didn't come up with the terminology. It soon became apparent that trying to lump paper and silk into the category of "resinous" materials was not useful. After about a decade and a half, the terms got changed to positive and negative charge. Perhaps the change in terminology is why Du Fay is often left out of textbooks. The terms he used were too old-fashioned to carry.

Top Image: Thomas Bresson

[Via Alchemical.org, Purdue.]


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