CHAPTER V. 



MINERALOGY. 



Outline of the History of the Science Crystallisation Crystalline Forms 

 System of Mohs Instructions for Forming a Collection Investigation 

 of the External Characters of Minerals Use of the Blowpipe Practical 

 Exercises, &c., &c. 



AUTHORS: Phillips, Brooke, Griffin, the Abb Haiiy, Beudant, Werner, 

 Berzelius, Weiss, Mohs, Neumann, &c., &e. 



COLLECTIONS : The British Museum, and the Collections of the Universities 

 and Public Institutions. 



THE science of geology consists essentially of mineralogy, 

 physical geology, fossil botany, and palaeontology. As these 

 pursuits are of the most extensive nature, and each would, 

 in fact, demand the study of a life fully to acquire it, we 

 shall content ourselves with offering that elementary and 

 practical information which will serve as an introduction 

 to the larger works, to which we refer the student for more 

 ample particulars. 



"We have already remarked, that a proper acquaintance 

 with mineralogy must form the basis of geology. There are 

 substances of common occurrence, so similar to each other, 

 that they can only be discriminated by an acquaintance with 

 mineralogy and by the operation of the blowpipe. Some 

 varieties of feldspar so closely resemble certain kinds of 

 hornstpne, that they can only be recognised by being fusible, 

 while many of the plutonic and volcanic rocks are so nearly 

 alike, that a knowledge of mineralogy can alone enable us 

 to distinguish them. "We may further add, that the Ger- 

 mans, who study every science so profoundly, exact from the 

 student at their universities, a due proficiency in mineralogy, 

 before he is allowed to commence the pursuit of geological 

 science. 



The following outline of the progress of mineralogy is 



