PART I. 



THE DISTINCTIVE CHARACTERS OF MINERALS. 

 Preliminary Remarks .The various bodies which occur in Natur 

 are of two general kinds-Organic and Inorganic, respectively Th 

 former constitute Vegetables and Animals, and all bodies of vege 

 e or animal origin. In the living state, they possess certain 

 structural parts or organs by which they assimilate or take into the* 

 .bstance external matter, and thus increase in bulk or maintain 

 vitahty Inorganic bodies, on the other hand, are entirely destitute 

 of functional organs of this nature. They comprise all product of 

 chemical, electrical and mechanical forces, acting independent? of 

 hfe; and thus mclude all metals, stones, and rocks, and also air and 

 water. 



Mineral or inorganic bodies are in themselves, also, of two general 

 Some possess a definite composition and definite physical 

 characters Others are mixed bodies or compounds of more or 

 variable character. The former constitute simple minerals or nT 

 erals proper ; the latter form rocks or rock-matters. In Parts I and 

 this Treat,se, minerals proper are alone considered. Rocks ar 



scz.'Srjr under reviev in part ra - * - 

 3SLTfti^- on r T by , certain characters 



form, degree of hardness, 



Mineral characters are of two principal kinds : physical or external 

 and ck emwal , respectively. Physical characters comprise the variTus 

 properties exhibited under ordinary conditions by mineral bodi s 

 colour, form, Ac. are examples, Chemical characters, on the other 

 hand compose the properties developed in minerals by the applica- 

 on of heat, or by the action of acids or other re-agents, by which in 

 general, a certain amount of chemical decomposition is effected 



