Made of Lancaster. 57 



talline groups. Ten years since I prepared fac simile 

 drawings of the principal crystals upon which this opinion 

 is founded. These figures were freely circulated among 

 the various mineralogists who visited me at Lancaster. 

 Among others^ they were shown to President Cooper^ of 

 Columbia College, S. C. who urged me to publish them, 

 which I promised to do in the Boston Journal of Science 

 and Arts ; but that publication having soon after ceased 

 to appear, I never laid them before the public. I men- 

 tion this to account for the fact, if my notions on this 

 subject should now be found wanting in novelty. I ob- 

 serve Mons. Beudant, in his Mineralogy, published two 

 years since, advances as his opinion, that Made is only 

 a variety of Andalusite filled in its interior with clay 

 slate, m which it had crystallized while that rock was in a 

 gelatinous state. He differs from me in some of his view^s, 

 especially in considering each Made as one cry^stal, while 

 I maintain, that they are mostly groups of crystals, assem- 

 bled together by the law of groupment y and prevented, in 

 some instances, from coming in contact, by the argilla- 

 ceous paste in which they were formed. The drawings 

 and specimens I have given will prove the correctness 

 of my views. Plate IV. Fig. 1st, a h represents the 

 two extremities of a crystal two inches long. It will be 

 observed, that the black substance in the interior of the 

 group has a pyramidal form, the base being represented 

 by a and the summit by J. Fig. 2d, c rf, a crystal three 

 inches in length, which shows the separate Individual 

 crystals constituting a group or Made. The form is per- 

 ceived to be generally that of a right square or rectangular 

 prism, some of them ha\dng been rendered a little rhombic, 

 by unequal pressure during crystallization. Fig. 3d, ef 

 represents the two extremities of a crystal two inches 

 "Tong, having on its transverse section the perfect figiu^e of 



VOL. I. PART I. 8 



