"Underclay" Quotes from Famous Books
... would undertake a microscopical hunt for infusoria in the underclay and shales; it might reveal something. Would a comparison of the ashes of terrestrial peat and coal give any clue? (554/3. In an article by M. F. Rigaud on "La Formation de la Houille," published in the "Revue Scientifique," Volume II., page 385, 1894, ... — More Letters of Charles Darwin Volume II - Volume II (of II) • Charles Darwin |