JF Ptak Science Books Quick Post
I thought to share this image, a detail of an engraved plate illustrating and article by the I-can-do-anything David Brewster, “On the Optical Phaenomena of Tourmaline, &c., within Mica and other Minerals”, appearing in the Philosophical Magazine for 1853 (plate opposite page 185). I believe it is a magnification of titanium set in mica: “…the transparent groups are much more beautiful than the opake ones, the crystalline ramifications having the most diversified forms, resembling often regular organizations (page 265).
The detail:
And the full engraving:
