lii INTRODUCTION. 



being yet imperfect; and particularly from our being still 

 almost wholly ignorant of what determines the properties of 

 compounds so complicated as minerals generally are. All the 

 ingredients are not to be regarded as equally energetic, or as 

 in the same proportion contributing to the peculiar constitu- 

 tion of a compound ; and if one, which in its relation to 

 others is comparatively feeble in its action, be present in 

 large proportion, it leads to erroneous conclusions, when, in 

 determining composition, we attend merely to the relative 

 quantities of the principles, without attending to their rela- 

 tive energies. This has been generally hitherto done; and 

 among the earthy fossils, the predominating principle has 

 always been regarded as that which is present in largest pro- 

 portion, though the reverse is probably frequently just."* 



5. Miscellaneous Observations. 



This introduction shall be closed with some miscellaneous 

 remarks, which may not be found unuseful for the previous 

 consideration of the reader. 



The science A grand cause, as elsewhere observed, of the slow progress 

 too extensive. Q m ineralogy, when compared with other parts of natural 

 history, is that it is too wide for the labours of one man ; 

 whence some important parts have remained uncultivated, 

 while others, often comparatively minute, have been discussed 

 with great care and anxiety, according to the peculiar studies 

 and inclinations of the several authors. The progress of 

 zoology and botany has been greatly assisted by the publica- 

 tion of detached works upon several divisions j and even the 

 mosses and lichens have been found sufficient for one man's 

 attention, in the brevity of human existence. Recent authors 



* Murray's Chemistry, iii. 7. He had already said, p. 5, " each simple 

 earth giving its name to an Order, under which are arranged the fossils in 

 which it is predominant, or to which it gives a predominating character" And 

 so Bergman, the father of modern mineralogy, in the preface to his Sdagra- 

 phia, 1782 : "I have derived the genera from the dominant principle} and the 

 species from the diverse mixtures." 



