PART I. 

 TERMINOLOGY. 



GENERAL CONSIDERATION OF MINERALS. THEIR DISTINC- 

 TION INTO SIMPLE, COMPOUND, AND MIXED. DIVISION OF 

 THEIR NATURAL-HISTORICAL PROPERTIES. 



. 20. POWER OF CRYSTALLISATION, AND ITS PRO- 

 DUCTS. 



That power which produces the individual (. 6.) 

 in the Mineral Kingdom, is termed the Power of 

 Crystallisation. 



This name has been applied, because the most eminent 

 and perfect productions of that power are Crystals (. 26.). 

 The power of Crystallisation is included in the general 

 idea of the Individualising power, which tends to produce 

 individuals in all the three kingdoms of nature ; and which 

 refers equally well to regular crystals, and to such indivi- 

 duals of the mineral kingdom, as are produced by the power 

 of crystallisation, although they are not crystals them- 

 selves, as will be shewn in another part of this work. 



Individuality does not require regularity, but it implies 

 unity of form (. 6.). An individual, whatever may be its 

 form, fills the space occupied by that form, with a certain 

 matter (. 23.), and thus it represents a whole, being co- 

 herent in itself, and limited towards the outside. For this 

 reason, the individual is a single body, and, as such, by it* 

 self a fit object for the consideration of Natural History. 



When minerals pass into the state of individuality, they 

 at the same time are endowed with the rest of those natu- 

 ral-historical properties which are peculiar to them in that 

 state of distinct existence ; and hence these properties 

 must likewise be considered as produced by the power of 



