.Review of CleavdandPs Mineralogy, 47 



standard of comparison, in describing the other species 

 which have lime for their basis, and some of which are com- 

 paratively rare. The same remark we would make upon 

 quartz, and its concomitant, pure silicious stones. There ap- 

 pears to us a high advantage in making these minerals clearly 

 known first, before we proceed to those which are much more 

 rare, and especially which are much harder, and possess the 

 characters of gems. For example, if a learner has become 

 acquainted with quartz, chalcedony, flint, opal, chrysoprase, and 

 jasper, he will much more easily comprehend the superior 

 hardness, &c. and different composition of topaz, sapphire, 

 spinelleruby, chrysoberyl, and zircon, which we should much 

 prefer to see occupying a later, than the first place in a tabular 

 arrangement ; and, although topaa, by containing fluoric acid, 

 appears to be in some measure assimilated to saline minerals, 

 it is in its characters so very diverse from the earthy salts, that 

 •we have fair reason to conclude that the fluoric acid does not 

 stamp the character; and, as it bears so close a resemblance 

 to the ruby and sapphire, which evidently derive their princi- 

 pal characters from the argillaceous earth, we perhaps ought 

 to infer that this (the topaz,) does so too. Indeed Professor 

 Cleaveland has sufficiently implied his own opinion, by giving 

 these minerals a juxtaposition in his table, although the same 

 reasons which induced the placing of the topaz next to the 

 earthy salts, could not have justified the placing of the sapphire 

 there. On these points we are not, however, strenuous ; they 

 are of more importance if the work be used as a text-book for 

 lectures, than as a private companion. With respect to the 

 completeness of Professor Cleaveland's tabular view, we have 

 carefully compared it with the third edition of Jameson's 

 mineralogy ; and although a iew new species, or sub-species, 

 and varieties have been added in this last edition, they are 

 in general of so little importance, that Professor Cleave- 

 land's work cannot be considered as materially deficient; 

 and the few cases in which it is so, are much more than made 

 up by his entirely new and instructive views of American 

 mineralogy, to which no parallel is to be found in any other 



