Note 3 — Chapter I
Reading edition
The chlorite slate of the Wissahickon, near Germantown, considered as primitive, contains similar pyrites with octahedral crystals of iron ore.—Nuttall.
Reading edition
The chlorite slate of the Wissahickon, near Germantown, considered as primitive, contains similar pyrites with octahedral crystals of iron ore.—Nuttall.