|History of the pH Scale ... it
was the year 1909 ...
In a publication of 1909 (see
reference below), the Danish scientist Soren P.L. Sörenson discussed the inadequacy of
measuring acidity by the total amount (normality) of acid additions to a particular
solution. The added amount of acid would not necessarily be a true measure of its
dissociation, depending on chemical interactions with other chemical species. Sörenson
proposed that the actual degree of acidity should be rationally measured by hydrogen ion
concentration and proposed the pH scale for expressing the hydrogen ion concentration as
detailed in the quote below:
"I will explain here that I use the name "hydrogen ion exponent" and the
designation PH for the numerical value of the exponents of this power."
Sörenson reportedly was involved in work testing the acidity of beer
and the pH symbol rooted in the French "pouvoir hydrogene"
(power of hydrogen).
The pH variable is obviously a very important variable in aqueous
corrosion studies and often monitored as a process variable, together with corrosion
S.P.L. Sörenson: Biochemische Zeitschrift, 21, 1909,
There are numerous articles on the web related to Sörenson
and the pH scale - try the popular google search engine.