births
S. P. L. Sørensen, Danish chemist and academic (died 1939)
Related Wikipedia articles
S. P. L. Sørensen
Danish chemist (1868–1939)
Søren Peter Lauritz Sørensen was a Danish chemist, known for the introduction of the concept of pH, a scale for measuring acidity and alkalinity.Source: Wikipedia (CC BY-SA)
January 9
Day of the year
January 9 is the ninth day of the year in the Gregorian calendar; 356 days remain until the end of the year.Source: Wikipedia (CC BY-SA)