the world > the earth > structure of the earth > structural features > sedimentary formation > [noun] > stratum > stratum by constitution > fuller's earth
fuller's eartha1350
walker's claya1398
fuller's clay1581
cledge1724
wall-earth1724
walker's soap1839
1724 Philos. Trans. 1722–3 (Royal Soc.) 32 420 The lower half of the Layers of Fullers-Earth, they call the Wall-Earth.