In the darkest hour: Analyses of a black spot on the last page of the diary of polar explorer Jørgen Brønlund (d. 1907)

Abstract

The three members of Sledge Team 1 in the Denmark Expedition of 1906–08 died in the fall of 1907 trying to return to the basecamp in Danmarkshavn in north‐east Greenland. In their final approach they attempted to make it across 79‐Fjord towards a depot on Lambert's Land on their dog sledges, but were impaired in doing so by rough ice scape, exhaustion and hunger. The last to die was Jørgen Brønlund. His body was found four months later, along with his diary, which on the last page gave a short explanation of what happened. Below his signature was adhered a foreign black spot. The spot has been analysed by inductively coupled plasma mass spectrometry, X‐ray fluorescence, synchrotron radiation powder X‐ray diffraction, Raman spectroscopy and pyrolysis gas chromatography mass spectrometry, which cast a light on the last hours of Brønlund's life. The analyses confirmed the presence of key minerals used in the production of natural rubber. Furthermore, traces of fat and petroleum derivatives combined with the sample morphology suggest that the spot originated from a rubber gasket, accidentally charred on Brønlund's attempt to preheat his Lux kerosene stove with different flammable materials in want of methylated spirits.