stone-butter

In Germany the workmen employed in the quarries of sandstone worked at the mountain of Kiffhauser spread a very fine clay upon their bread, instead of butter, which they call steinbutter* (stone-butter).

Travels to the Equinoctial Regions of America 1851

In Germany the workmen employed in the quarries of sandstone worked at the mountain of Kiffhauser spread a very fine clay upon their bread, instead of butter, which they call steinbutter* (stone-butter).

Personal Narrative of Travels to the Equinoctial Regions of America, During the Year 1799-1804 — Volume 2 Alexander von Humboldt 1814