ELASTIC MINERAL PITCH. 867 Geognostic and Geographic Situations. It isjfound in the cavities of a vein in the leail-mine called Odin, which is situated near the base of Mamtor, to the north of Castletown in Derbyshire. The vein traverses limestone, and contains galena or lead-glance, accompanied with fluor-spar, calcareous-spar, heavy-spar, quartz, blende, calamine, selenite^ and slaggy mineral pitch. Observatio7is. 1. According to Hatchett, a transition is to be ob served from Mineral Oil, through Slaggy Mineral Pitch, to Elastic Mineral Pitch. 2. Like the elastic gum, called Caoutchouc, it removes the traces of graphite, (black lead), but it at the same time soils the paper a little. 3. The first account of this mineral was published by Dr Lister in the Philosophical Transactions for 1673 *. It was found in an old forsaken mine. He calls it a subterraneous fungus, and is uncertain whether it belongs to the vegetable or mineral kingdom; but rather incline* to the former, and hint3 that it may have grown out of the old birch props used in the mine. It was first accp I'ately examined by Mr Ilatchett. 3. Brown Coal. This species is divided into six subspecies, y!z. Bitu- vinous Wood or Brown Coal, Earth Coal or Earthy Brown Coal, Alum Earth, Common Brown Coal or Con- choidal Brown Coal, Granular Brown Coal, Moor Coal 0r Trapezoidal Brown Coal. First * Vol. viii.
