The Natural History Of Hartz-Forest, In His Majesty King George's German Dominions : Being a succinct account of The Caverns, Lakes, Springs, Rivers, Mountains, Rocks, Quarries, Fossiles, Castles, Gardens, the famous Pagan Idol Pustrich or Spit-Fire, Dwarf-Holes, Pits, moving Islands, Whirlpools, Mines, several Engines belonging to them; Ores, the manner of refining them; Smelting-Houses; several sorts of Ovens, Hammer-Mills, Vitriol and Glass-Houses, &c. in the said Forest: With several useful and entertaining Physical Observations ; Written in German By H. Behrens, M. D.