Page:Transactions of the Geological Society, 1st series, vol. 2.djvu/356

346 neglect them in early life, which I have now occasion to regret, not only as it forbids the pursuit of mineralogy to an extent which alone would have enabled me to illustrate its objects in a manner wholly pleasing and satisfactory, but also as it renders me incompetent to reap the pleasure and instruction, which the works of those celebrated men the Abbé Haüy and the Count de Bournon, are calculated to convey. It must of course follow, that the only evidence I can offer in regard to the admeasurement and value of the angles of crystals, must be wholly mechanical.

I have given much attention in the endeavour to ascertain precisely the value of the angles of this substance, by the help of that admirable instrument the reflecting goniometer of Dr. Wollaston, having been previously assisted in its use by some hints and