Note 9 — EPITOME OF ELECTRICITY.
Reading edition
Tourmaline is a species of silicious earth. Its colour is generally a blackish brown, though the tourmaline of Brazil is blue, green, red, or yellow. It is a compound substance, consisting of argill, silex, calcareous earth, and iron in different proportions; but argill and silex are always the chief ingredients. It is found in Ceylon, Brazil, and Tyrol; and it is also found in large quantities in the neighbourhood of Philadelphia, attached to masses of quartz.