Page "Alfred Nobel" Paragraph 13

Nobel's third and longest-lasting relationship was with Sofie Hess who was from Vienna, whom he met in 1876.

The liaison lasted for 18 years.

After his death, according to his biographers Evlanoff, Fluor, and Fant, Nobel's letters were locked within the Nobel Institute in Stockholm.

They were released only in 1955, to be included with the biographical data of Nobel.