Encyclopædia Britannica, Ninth Edition/Tourmaline
TOURMALINE.Electricity, vol. xiii. p. 99; Geology, vol. x. p. 228; and Minerology, vol. xvi. p. 409.
See also Tourmaline on Wikipedia; Tourmaline in the 11th Edition; and the disclaimer.
TOURMALINE.Electricity, vol. xiii. p. 99; Geology, vol. x. p. 228; and Minerology, vol. xvi. p. 409.