At which laboratory was Carsten Olsen employed as an assistant to the Danish chemist who introduced the concept of pH?
S. P. L. Sørensen: Søren Peder Lauritz Sørensen (9 January 1868 – 12 February 1939) was a Danish chemist, famous for the introduction of the concept of pH, a scale for measuring acidity and alkalinity.
i don't know