100 EXTERNAL CHARACTERS OF MINERALS. 



of the science ; the former being essential to a complete 

 acquaintance with the subject ; while the latter is indispen- 

 sable for acquiring a general knowledge of the same. 



EXTERNAL CHARACTERS or MINERALS. The next step 

 in the progress of the student will be to render himself 

 acquainted with the external characters of minerals ; and, 

 with the view of studying these and the practical details of 

 the science, it is essential that he should possess a properly 

 arranged collection ; and, if possible, that he should avail 

 himself of the assistance of a well-qualified instructor ; since 

 more may be learned in a few lessons from such a person, than 

 can possibly be gathered from books in a lengthened period. 

 Mr. Heuland, Mr. Sowerby, Mr. Stutchbury, and Mr. Ten- 

 nant, are in the habit of furnishing such collections. They 

 are likewise supplied by Mr. Abel, of Hamburgh, and Mr. 

 Krantz, of Berlin. The specimens comprising such a cabinet 

 need not be either large, showy, or expensive ; they should 

 be arranged according to the system of Phillips ; and, with 

 the exception of some of the more rare specimens, should 

 comprise the substances enumerated at the close of Phillips' s 

 Introduction, (Allan's edition, page Ixxx.) It will also be 

 necessary to procure another collection in fragments, prepared 

 expressly for analysis and fusion by the blowpipe. The works 

 required will be few ; that of Phillips should form the text- 

 book ; Berzelius on the Blowpipe, Griffin's Treatise on the 

 Blowpipe ; Sowerby' s British Mineralogy may also be con- 

 sulted with advantage. The copy of Phillips should be bound 

 with blank leaves, for the purpose of taking notes of the spe- 

 cimens composing the collection of the student, the lessons of 

 his instructor, and the general knowledge which he himself 

 acquires. His specimens should all be registered on the 

 blank pages, so as to point >ut their proper place in the 

 drawer ; thus -f^ may indicate that a certain mineral is 

 placed as the fourteenth object in the sixth drawer. The 

 student should also possess a set of models of crystalline 

 forms, which can be procured from the parties above-named. 



In addition to his own cabinet, he should farther avail 

 himself of the various public stores within his reach ; the 

 splendid collection of the British Museum may be consulted 

 with eminent advantage by the aid of the Synopsis. 



The reflecting goniometer will be found indispensable for 



