and Shepard's Treatise on Mineralogy. 347 



cies as the entire mineral kingdom. It is for this latter reason a matter 

 of doubt, whether a systematic nomenclature, analogous to that in the 

 other departments of natural history, will ever be adopted in mineralogy. 

 " The trivial names only, therefore, are employed in the present work ; 

 and in those few cases where none such have ever been applied to well 

 established species, the attempt has been made for the sake of uniform- 

 ity, to supply the deficiency. In the descriptive part of the work, the 

 leading synonyms will follow (in smaller type) the trivial names adopt- 

 ed for each species." — p. 94. 



It is well known that Prof. Shepard is a disciple of Mohs, 

 in relation to the determinations and arrangement of minerals. 

 Chemical evidence has therefore with him no decisive weight, 

 unless it is corroborative of natural history characters. But hap- 

 pily Prof. S. has not been so far consistent as to banish the blow- 

 pipe and the test-case, and he still resorts to analysis in deter- 

 mining the nature of minerals, although in regard to classifica- 

 tion, he would supersede its results if they were at war with 

 the characters of natural history. Difference of constitution is 

 with this class of naturalists an accident, with which the mine- 

 ralogical student has little to do. He knows quartz and dia- 

 mond by their hardness, gravity, and lustre, rather than by the 

 silica of the former and the carbon of the latter. It is however 

 no valid objection to the chemical method, that in describing 

 a bird or a fish we do not dwell on the carbon, hydrogen, 

 nitrogen, and oxygen, which enter into their composition, or the 

 phosphate of lime which gives stability to their bones ; for, 

 there is a wide and irreconcilable distinction between the re- 

 sults of vital force in the production of organized forms, and 

 those of molecular attraction which govern the characters of 

 crystallized minerals. The one is organic and vital ; the other 

 purely chemical. On this difference are founded two great sys- 

 tems of natural knowledge, and any attempt to overlook it or 

 undervalue its importance, must lead to error. 



Gravitation is not more essentially connected with astronomy, 

 than chemistry with mineralogy ; and the student who is ignorant 

 of the composition of his minerals, might with equal profit possess 

 a cabinet of glass of divers hues. It is said that many blind per- 

 sons have a delicacy of touch, which enables them to distin- 

 guish, not form only, but colors, and that they may even appre- 

 ciate the beauty of a picture, yet we see in this fact no argument 

 for the rejection of vision in estimating the value of works of art. 



