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I've spent quite a lot of time now researching what I can find online about the story of how Ben Franklin assigned the terms positive and negative to what had previously been called vitreous and resinous, respectively. Ben thought that when he rubbed his glass rod with silk or wax that the glass was left in a state of having an excess of "electric fluid"[1]. He was also a proponent of the "one fluid" theory which we now know is incorrect because the electric field arises due to charge separation, not the "lack of electrons", but I digress.

Anyways, there are a bazillion tutorials out there about how we're stuck with the convention that was set by Franklin, but I have been completely unable to find out why this is. There is no trail of references that I can discern.

For example, the next major milestone after Franklin's use of the terms positive and negative in his experiments are probably Volta's pile experiments. In the drawings of his setups that I've been able to find on the internet, I see uses of the terms positive and negative, but there's no glass or wax involved in the voltaic pile. How did Volta select these terms? For that matter, how did every other 19th century experimenter implement Franklin's terminology?

To say that "Franklin set the convention and now we're stuck with it" is not good enough. There has to be a chronology, and a history of decisions amongst the prominent experimenters, no?

[1] http://www.gutenberg.org/files/45515/45515-h/45515-h.htm

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Franklin arbitarly named two things. And since they summed to nothing, it made sense to use names that were suggestive of surplus and deficit, such that they cancel out.

There was no way to know which was actually "gaining" anything and which was "losing" anything. He assigned them completely arbitrarily.

He made a list saying which material went positive and which went negative when you rubbed them together. Others added more material interactions to this list. For consistency the terms had to remain the same. Changing them would have been like changing North for South. Why?

Fast forward to the modern day. Many people believe Benjamin got it wrong because current is the opposite direction to the movement of electrons in a wire. They believe that an excess of electrons happens only by gaining an electron, hence electrons should have been positive.

That is off course a complete misconception, as you could also say the addition of a positive charge results in an excess of protons, hence protons should be positive.

The reason people are confused by this is they mostly deal with currents of electrons (in wires) and don't understand that there are currents of protons (such as in water, batteries, fluorescent lights, etc.).

Putting together a detailed chronology is hard because at this point in history electrostatics was extremely exciting and easy to experiment on. Experiments would be repeated by hundreds of scientists all of the world. There was a real sense that they were closing in on the power of God With these magical shocks. Even common people could repeat the experiments.

Try starting with names like D.Gralath, J.Allemand, G. Monnier and of course L.Galvani. These guys often quickly repeated and built on electrostatic experiments, reusing terms including Franklin's.

It would be a huge undertaking to track usage. Probably require figuring out where Franklin's work went and who would have read it first and published experiments based on it.

(You get the impression from Volta that it was already a well understood convention to use the same names as Franklin).

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Why does there have to be a chronology? I believe your ending question is indicative of the most probable answer. Either the great debates between early experimenters weren't recorded or they didn't exist in the first place.

I literally looked in every book I own related to engineering, physics, math, chemistry, and every other book I could find with even a hint of a technical discussion before answering this question and I found exactly nothing. That doesn't necessarily mean anything and maybe someone will post a definitive answer five minutes after I press submit, but it appears as though the origin is as unexciting as because he set the convention and now we're stuck with it.

There was probably some initial discussion, but my guess is the arbitrary definitions stuck due to a lack of any contrarily compelling evidence.

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  • \$\begingroup\$ There has to be a chronology because things happen in sequence? There's a tendency in the Science and Engineering world to present the convention as fact, but there's surprisingly little evidence for this, at least that I was able to find in a week of internet searching and reading incredibly old texts on Gutenberg. I think it would be highly interesting to see how the terms and conventions were decided upon beyond and after the link that I posted. It's really a job for a science historian. Thanks a bunch for checking out your books I appreciate it! \$\endgroup\$ – mhz Aug 10 '15 at 2:24
  • \$\begingroup\$ I don't follow why there has to be a sequence of events other than Ben created the lingo and other people adopted it. I understand what you're saying, but I don't see why there must be anything more complex than that. I agree it's probable that the conversations happened, but not necessary and, at this point, it's looking like that information may either be lost or incredibly hard to find. Edit: I think you're right - this is a job for a historian. I'm going to ask a few friends who are in that area of academia to see if we can get some answers. You've got me interested. \$\endgroup\$ – Anthony Aug 10 '15 at 2:36
  • \$\begingroup\$ I think my example of Volta's pile is a good one. The electrodes are made of different types of metal, not glass and wax, so it's not as simple as Volta simply adopting the lingo. My hunch is that Benjamin's lingo was adopted in the use of the test equipment of the time and that's how the terms became fixed (for example, Volta may have decided which end of his pile was positive through using the same electrostatic apparatus, Leyden jars, glass, wax, etc., using Franklin's terminology, so this question might be more accurately asking about the history of eletric test equipment. \$\endgroup\$ – mhz Aug 10 '15 at 17:33
  • \$\begingroup\$ If there's a writing of Volta's somewhere describing how he came to decide which end of his pile was positive that would be a direct explanation as to how all batteries came to have their + and - signs designated. I appreciate your interest, thanks! \$\endgroup\$ – mhz Aug 10 '15 at 17:35
  • \$\begingroup\$ It could be coincidence, too. Is there any reason to think that early experimenters knew that electrostatics and electrochemistry were examples of the same physical process? You could make little sparks with batteries, but it's quite a leap (so to speak) from there to lightning. \$\endgroup\$ – Martin Ewing Aug 12 '15 at 0:41

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