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TRANSACTIONS OF THE ROYAL CANADIAN INSTITUTE [VOL. XI 
22. 
23. 
* a 
la 
EXPLANATION OF FIGURES. 
. Immature pit in shallow depression, Colemanite (o10), 1% 
Acetic Acid, 100°. 
. Two adjacent pits connected by a tube, Colemanite (o10), 
1% Acetic Acid, 100°. 
. Immature pit in shallow depression, Colemanite (o10), 1% 
Hydrochloric Acid, 100°. 
. Pits in parallel arrangement, Colemanite (o10), 2% Hydro- 
chloric Acid, 100°. 
. Pit on Colemanite (010), 2% Hydrochloric Acid, 100°, after 
second exposure. 
. Deep pit remaining after a third exposure as above. 
. Typical symmetrical pit, Colemanite (010), 100°, third exposure. 
. Asymmetric pit, Colemanite (010), 4% Hydrochloric Acid, 100°. 
. Beaked pit, Colemanite (010), 6% Hydrochloric Acid, 100°. 
. Very immature pit, Spodumene (110), Sulphuric Acid and 
Fluorite, 15 minutes. 
. Second type of pit, less immature, Spodumene, as before. 
. Third type of pit, Spodumene (110), as before. 
. Beaked pit, Spodumene (110), as before. 
. Fifth type of pit showing rudimentary beak, Spodumene (110), 
as before. 
. More mature pit, Spodumene (110), Sulphuric Acid and 
Fluoric Acid, 30 minutes. 
. Deeper form showing a perpendicular and a curved side, 
Spodumene (110), as before. 
. Four-sided pit on Spodumene (110), fused Sodium Hydrate, 
2 minutes. 
. Five-sided pit on Spodumene (110), as before. 
. Six-sided pit on Spodumene (110), as before. 
. Shallow five-sided pit on Spodumene (110), as before. 
. Primitive pit, a mere shallow depression, Diopside, De Kalb, 
N.Y. (110), Sulphuric Acid and Fluorite, 2 minutes. 
Pit in second stage, Diopside (110), same corrosive, 4 minutes. 
Unusual asymmetric pit, Diopside, Zillerthal (110), same 
corrosive, 4 minutes. 
Fig. 24. © Typical pit, Diopside, Zillerthal (010), same corrosive, 16 
minutes. 
