Madison Cr. 1876. Potter's clay. Quality 1. Upper Silurian. Black, gruni E of Richm nd. A light soft grey clay with some ochreous stains + infiltration. 1876. Potter's clay. Quality 2. Same locality, of a bluish greyish, Silica 59.976 56.96 Al. Iron & mag. Oxid 27.640 28.74 Lime carb, .280 .20 Magnesia .606 .752 Pot ash 3.931 2.502 Soda .547 .315 Combined H2O loss 7.020 10.531 Nr Nr 1876a 1876b B atty Co. For Olympian & Spring see 1p. 17, (363 cut. 200's) 1989. Ferruginous Magnesia limestone. lime diath under Black Dermia shale, Lime carb, 54.06 Mag. Carb, 34.027 Iron carb, 11.532 or Os .006 Pot ash .143 Soda .040 Silica .280