Professor R. Sissingh ( -1927)
1928 Obituary 
R. SISSINGH, a Knight of the Order of the Lion of the Netherlands, and professor of experimental physics at the Amsterdam University, graduated at the University of Leyden and worked there with Prof. Kamerlingh Onnes. His thesis entitled " Measurements of the Elliptic Polarization of Light " attracted much attention in 1885. He continued to lecture at the University of Leyden until 1890. He then became professor at the Delft Polytechnic.
In 1897 he was appointed professor at the Amsterdam University and devoted much attention to experimental and research work. The study of problems in connection with light remained his favourite field of research and the many theses that were written under his guidance are evidence of this. Many of them will be found in the Proceedings of the Royal Academy of Sciences of Amsterdam, the Annalen der Physik, the Philosophical Magazine, the Archives Nderlandaises, and the Physikalische Zeitschrift.
He died at Amsterdam on the 23rd October, 1927.
He joined the Institution as a Foreign Member in 1892 and was elected a Member in 1911.