The works which have been studied, more particularly, in 

 forming these tables, are alphabetically the following: Berzelius, 

 (Children's translation,) Cleaveland, (second edition,) Griffin, 

 Jameson, (third edition and Manual,) Mohs, (Haidinger's trans- 

 lation, 1825,) Phillips, (third edition,) and Shepard,* and not 

 one of the prominent characters made use of in them has been 

 assigned to a mineral, until reference has been made to most of 

 these authorities, excepting only the first and last; the former 

 being authority alone for some of the pyrognostic characters, 

 while the latter never describes any which are chemical, reserv- 

 ing them for his second volume ; so that if this attempt should 

 prove a failure, it will not arise from want of industry on the 

 part of the Compiler, whose original object in the undertaking, 

 self improvement, will have been attained, whatever opinion 

 may be ultimately expressed of the result of his labors. In the 

 mean time, it must be confessed, (his only excuse for offering 

 them to the public,) that the Compiler is not without the hope, 

 that while, as tables of reference, they will be consulted more 

 readily than any before published, they will, at the same time, 

 rarely disappoint the individual who may consult them, as lon^r, 

 at least, as his enquiry is directed to metallic minerals, which 

 have been fully described. 



Before I conclude this introductory portion of my essay, it 

 may be proper to remind the reader that the forthcoming tables 

 are intended to facilitate an effectual reference to systems of 



* This young and promising naturalist and chemist, has recently (1832) put forth 

 the first volume of a Treatise on Mineralogy, in which a tabular form similar to the 

 one here made use of, is, I think, for the first time adopted. In it, whenever possi- 

 ble, (contrary to the plan pursued in this arrangement,) the crystallographic char- 

 acter has been made the characteristic or most prominent feature ; a more scientific 

 method certainly, but one less accessible to the generality of students than that 

 founded on the more obvious characters derived from the use of the blowpipe, par- 

 ticularly as regards metallic minerals. In the study of mineralogy we should never 

 lose sight of its principal object, viz. to ascertain either what a mineral is or what it 

 is not, and the readiest means to effect this should be employed, whether scientific 

 or empirical. But if we are often to look for almost invisible cleavages, or to meas- 

 ure nearly microscopic angles, with instruments unmanageable by common hands, 

 in order to deduce primary forms by perplexing observations or calculations, the 

 arena of the science will be closed against all except professors and their assistants. 



