Marinus Herman de Jongh was a son of Maximiliaan de Jongh and Gellina Naämah Cohen.
Stadsarchief Amsterdam, archiefkaart Maximiliaan de Jongh
The first post-war issue of 'Het Hormoon,' the corporate journal of the Organon group, commemorated the staff who had perished in the war. Marinus Herman de Jongh worked at Organon's printed matter centre from 6 February 1940 until he was dismissed in 1942 for being Jewish.
Jewish Historical Museum, Documents collection, inv.nr 3909; 'Het Hormoon', May/June 1946, 95