Why is current symbolised by an I

[asto5]

Just doing a bit of revision, when i suddenly wondered why current was symbolised by an I not a C. I know capacitance is symbolised by a C, but i would have thought that current would have been "discovered" and therefore symbolised first?
just wondering whether anyone has any input on the matter?

cheers in advance

[Quizmonster]

Click here for a physicist's answer and read the Admin Note at the bottom.

[north star]

Capacitance is measured in farads (F)

C is the symbol used for electric charge (Coulombs)

[4candles]

<pedant mode on>

Capacitance is measured in Farads, and the unit symbol is F.
Charge is measured in Coulombs, and the unit symbol is C.
Current is measured in Amps, and the unit symbol is A.

But the quantity symbols used in formulae are C, Q and I respectively.

<pedant mode off>

[MatydaLover]

More pedant stuff ...

I is used for current and so is i ... they are both current, but have different meaning.

[Quizmonster]

Yes, but does anyone have any idea why 'I' is the symbol for 'current' - as put in the question - other than the one suggested by the physicist on the Madscientist website in my earlier response?

[4candles]

It's suggested here that it's Intensity

http://amasci.com/~billb/cgi-bin/elect/guest03 .html

[Space]

it's I as in Intensity

[Quizmonster]

Please don't think that I'm doubting that 'I' does stand for 'intensity' re electricity, but it seems that - in 19th century physics - 'intensity' was used for a range of forces (for want of a better word) including light/brightness. (I base that on what The Oxford English Dictionary has to say on the word.)
What we seem to have here is a pair of scientific websites with each element saying different things. Is there a physicist - better qualified than the ones already heard from on the WWW links - in the house?

(My interest is purely linguistic...science is a closed book to me!)

[beso]

A number of electrical relationships using vectors. For example a phase relationship can be represented by a vector with the volage shown in the x axis while the y axis shows current.

The y axis in complex numbers such as vectors is normally designated the i or imaginary plane. Perhaps this did assist in the i designation being retained even if it didn't actually start out as the cause.

[Quizmonster]

Ah! So now we have impetus, intensity and imaginary...the plot thickens, Beso!