200 PROCEEDINGS OF 



sometimes without a central spot corresponding with the shape of tlie crystal, of a 

 different tint or texture from the rest. One or two of these that I send, have a 

 reddish tinge in the gray, and I have conjectured that some more strongly tinged 

 varieties of this kind may have induced Dr. Jackson to speak of them as anda- 

 lusite ; to which, otherwise, I have seen no resemblance iu any crystals I have ex- 

 amined. Andalusite is usually hard enough to make a slight scratch upon quartz ; 

 while these grayish crystals may be cut or scraped with the point of a knife. This 

 variety also atlbrds instances of intersection. 



As a fourth variety, I have ranked those described as resembling granalite in 

 external characters, other than the hexagonal shape and crossing. In some of 

 these, while the texture of the crystal seems tiie same, the insertion of the internal 

 crystal, and the connecting lines of tlic angles, arc distinctly marked bj' a light 

 furrowed line, as of a joining. Some variety of this kind may be that of which 

 Dr. Jackson speaks. He obtained his specimens from a locality several miles dis- 

 tant from me, and which I have never examined. 



BPECIMENS. 



Jn Paclcage No. 1. — These arc specimens of the most perfect form, having the 

 inner crystal distinctly marked, with the diagonal joinings, and the appearance of 

 duphcature of the outer investment to form the longitudinal diagonal. One of the 

 specimens is triangular, being half of a crystal divided in its natural cleavage 

 through the transverse diameter. Another is divided obliquely lengthwise, and tw'o 

 black lines may be observed traversing the crystal diagonally lengthwise. 



J'ackagc No. 2. — This contains specimens of those described as the second 

 variety, from the perfect form of those in No. 1, to a more central spot of the yel- 

 lowish matter, and two handsome specimens of the mottled kind. One of tliese 

 specimens, with a central dot, is an imperfect six-sided prism, and is half of one 

 of the crystals of a stauroidcan formation. The remainder of the cross accom- 

 panics this package. 



Package No. 3. — Specimens of the gray and blackish variety, without any en- 

 closed yellowish matter, but one or two of tlicm with a darker nucleus, similar in 

 shape to the external crystal. One of the gray crystals is an instance of an oblique 

 intersection. This specimen is split longitudinally, and shows one crystal passing 

 tlirough the other. 



Package No. 4. —Specimens of the dark reddisli, brown variety, very hard, 

 brittle, and difficult to bo detached from the matrix. One of them has a perfect 

 formation ; in tlie others it is not to bo discovered. 



Quere. — Are not tliese last crystals radically distinct from the others, and oven 

 from tlie perfectly shaped one with them ? 



All of the crystals that I have seen, have been found in the detached masses 

 spoken of. I have never met with them in any ledge, though others Jiavc told mc 

 that they hare found them so. I have fancied, from my own observation, tliat they 

 mistook the projection of some huge half-buricd fragment for the outcroppmg of 

 strata, aa they wore person* of little experience iu such researches. 



