On the Nile alluvium of Nubia : extract of a letter from Dr. Richard Lepsius to Dr. S. G. Morton, relative to the language of the Bishareens of Nubia, and the alluvial deposits of the Nile ; with an analysis of those deposits by Prof. Walter R. Johnson. - Lepsius, Richard, 1810-1884 (Acad. of Natural Sciences, 1845)