Question: At which laboratory was Carsten Olsen employed as an assistant to the Danish chemist who introduced the concept of pH?

Related documents: [0]  [DOC] 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. He was born in Havrebjerg, Denmark. [END] 
[1]  [DOC] Carsten Erik Olsen (March 1, 1891 – August 19, 1974) was a Danish plant ecologist and plant physiologist, who pioneered the study of plant nutrition in soils of different pH. He was born in Copenhagen and began studies of botany at the University of Copenhagen in 1910, at first with professor Eugenius Warming, then with professor Christen Raunkiær. His doctoral dissertation (1921) was on the influence of soil pH on the natural distribution of plants. He was then employed by the Carlsberg Laboratory as an assistant to the chemist S. P. L. Sørensen, later in his own lab. There, he worked on plant uptake of ions, especially iron, nitrogen fixation and calcicolous plants. [END]  
Answer: Carlsberg Laboratory
Carlsberg Laboratory