accompanied by chalcedony from Pednandrae. In searching the heaps of that mine for the chlorophane, I found several varieties of remarkably compact fluor—also enclosing crystals of oxyd of tin, or accompanied by them.
The science of mineralogy is so intimately connected with some branches of the mathematics, that he who pretends to the former, unassisted by a knowledge of the latter, may perhaps be considered as pursuing it rather as an amusement, than as an object of scientific research. I confess myself to be exactly so circumstanced. The want of an attachment to the study of the mathematics, led me to
- Some of these fluors deserve particular notice on account of their exhibiting some peculiar characteristic differences when compared with common fluor. One large specimen is of a bluish colour, and is traversed in various directions by veins of what I
traversed in various directions by minute veins of chlorite, occasionally embedding yellow copper ore and oxyd of tin. It is hard; scratches glass easily; its fracture is shattery and splintery. Its general colour is purplish; it is transparent at the edges, and the fragments are very transparent; a thin piece held for a short time in the flame of a candle, emits a brilliant green light, which becomes very brilliant by placing it on a live coal, from which, if it be taken at about the height of its light, it may be repeated, though with diminished effect; by frequent repetition it becomes nearly colourless. It does not fly even in the centre of a common fire.