pH question!

[Dima Klenchin]

:In article <3861193C.C13E6AD4 at wgn.net>, vdrake at wgn.net (Vernon Drake) wrote:
:
:> Could someone tell me what the letters pH stand for?

Interesting question! Shamefully, I don't know. pH, pKa, etc but what is
the etymology for "p"? 

:I think it means "pons hydrous"  but I never took latin so do not hold be
:to it.  Now if it were a greek word, I would have no problem.

I vaguely recall some Latin which at a time I had no means not to take :-)

Pons means bridge and this does not really help me to understand 
the origin of pX =  -logX

        - Dima