S. P. L. Sørensen

S. P. L. 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.

From 1901 to 1938 he was head of the prestigious Carlsberg Laboratory, Copenhagen.^[1] While working at the Carlsberg Laboratory he studied the effect of ion concentration on proteins,^[2] and because the concentration of hydrogen ions was particularly important, he introduced the pH-scale as a simple way of expressing it in 1909.^[3] The article in which he introduced the scale (using the notation p_H^[4]), described two new methods for measuring acidity.^[5] The first method was based on electrodes, while the second involved comparing the colours of samples and a preselected set of indicators.^{[citation needed]}

On 29 May 2018 he was honoured for creating the pH scale in a Google Doodle.^[6]

Personal life[edit]

S. P .L. Sørensen was born in Havrebjerg in 1868. His father was a farmer; he began his studies at the University of Copenhagen at the age of 18. He wanted to make a career in Medicine but under the influence of Chemist S M Jørgensen, decided to change to chemistry.^[7]

While studying for his doctorate he worked as assistant in chemistry at the laboratory of the Danish Polytechnic Institute and assisted in a geological survey of Denmark. He also consulted the Royal Naval Dockyard.^[7]

He was married twice. His second wife was Margrethe Høyrup Sørensen who helped him in his studies.^[7]