278 Count de Bournon’s Description of 
wherein the crystallization appeared not to have attained its 
highest degree of perfection, which varieties I have distinguished 
by the name of imperfect corundum. But it has also been 
stated, that in proportion as the crystallization possessed a 
greater degree of perfection, the texture exhibited a less lami- 
nated appearance ; and that, in this case, it was less easy to 
obtain a fracture in the real direction of the laminae. 
Another circumstance has likewise been taken notice of, which 
appears to me to deserve some attention, namely, that in all the 
different varieties of this substance, the blue colour was gene- 
rally accompanied with a greater degree of transparency, of 
gravity, and of hardness ; and that, under these circumstances, 
in proportion as the adhesion of the laminae was more complete, 
the laminated texture of the stone became less evident, and it 
was much more difficult, and sometimes scarcely possible, to 
obtain fractures in the direction of the laminae. Nevertheless, 
among crystals and fragments of sapphire which had but a 
small degree of transparency, I have frequently met with some, 
in which the faminated texture was as evident as in the red 
prismatic variety of perfect corundum, or oriental ruby. 
With respect to what concerns the fracture of the sapphire, 
if the Abbe Hauy was not deceived by an illusive appearance 
by no means rare in this stone, both in its perfect and imperfect 
state, (according to which the terminal faces seem to indicate a 
laminated texture perpendicular to the axis, or a fracture in that 
direction,) I cannot account for his thinking that he had obtained 
such a fracture as he describes. I have often tried to obtain 
fractures of that kind, but without success; never having been 
able to procure any, except such as were more or less irregular, 
and exhibited an appearance very different from that of fractures 
