Miscellanies. 375 
the improvemts of Mous in relation to simple and compound va- 
rieties and to the numerical scale for expressing the hardness, and to 
my following Brooke in the treatment of the regular forms; not to 
mention the circumstance that my artificial tables enumerated a num- 
ber of species whose descriptions had not found their way into any 
English work. This was foreseen in the preparation of that vol- 
ume ; and notice was accordingly given in it, that a second part, de- 
voted exclusively to descriptions, and constructed in accordance with 
the principles of the first, was in preparation. 
‘In addition to the desire of supplying what was thus wanting to 
carry out the plan of study which had appeared to me to possess 
the greatest advantages, I was stimulated to the attempt, in the hope 
of being able to contribute something towards the more satisfactory 
determination of American localities; an undertaking for which my 
mineralogical travels had afforded me considerable facilities. In- 
deed, so numerous had been the discoveries in important mineral 
depositories since the last edition of CLravenanp’s Mineralogy, and 
the publication of Rosinson’s Catalogue, and so many doubtful 
points existed in relation to many of those quoted in these works— 
not a few having been erroneously announced, either through inac- 
curate determinations of the species, or their occurrence in trifling 
and accidental quantity—that the proposed work seemed justifiable 
solely on this ground, provided there was a reasonable hope of pla- 
cing the subject in a more just light. Besides, it was had in view to 
indicate the crystalline forms noticeable among our minerals, a point 
which had been so much overlooked as to have created a very un- 
favorable impression of the mineralogical riches of the country. 
There seemed room also, to perform a desirable service by appro- 
priating to the work, the latest discoveries of the German mineralo- 
gists, to whom the science is indebted for its most important ad- 
vances during the last ten years. 
“The alphabetical arrangement of the species has been adopted 
because it seemed most likely to subserve the convenience of stu- 
dents using my characteristic, or any other, in the determination of 
specimens ; as well as that of persons having occasion to refer to 
the descriptions for less general purposes, as for example, to learn 
only the crystalline form of a particular species, or to obtain infor- 
mation respecting its locality. Had the natural-historical arrange- 
ment, the chemical, or any mixture of the two, been employed, the 
inconveniences of consulting an index must necessarily have been 
encountered. 
