Miscellanies. 389 



Part II. treats of the Physical characters of minerals, or those de- 

 pending on light, electricity, magnetism and specific gravity ; also of 

 the hardness, state of aggregation, kinds of fracture, and odor. 



Part III, consists mainly of directions for the use of acids and of 

 the blowpipe. 



Part IV, treats of the classification and nomenclature of minerals, 

 and discusses the relative importance of crystallographic, physical 

 'and chemical characters in determining identity. The author here 

 brings forward the classes and orders of his natural classification, the 

 genera and species of which are given in Part VI. The classes, 

 and in general the orders, are similar in their characters to those of 

 MoHs. The following is the statement of its grand divisions. 



Class I, EpiGiEA, (containing two orders) includes the gases, un- 

 raetallic liquids and soluble minerals. They have in general resulted 

 from the decomposition of other species and are consequently epigsean 

 or superterraneous. Their specific gravity is below 3-8. 



Class II, Entogjea (twelve orders) comprises those insoluble min- 

 erals which occur in or compose the several rock strata, and which 

 are therefore appropriately described as occurring within [evTog^ the 

 earth. Specific gravity above 1*8. 



Class 111, Hypog^a, (two orders) contains those species that are 

 literally hypogaean, or have resulted from the inhumation of vegetable 

 or animal matter. Spec, gratr. above 1'8. 



Part V, contains two new tabular classifications the object of whicl^ 

 is to enable the unaided student to arrive at the names of minerals. 

 The first includes all crystallized minerals and is arranged according 

 to the systems of crystallization before mentioned. These classes 

 (with the exception of the class Triclinata) are each divided into 

 two sections, according to their unmetallic or metallic lustre. The 

 individuals in these sections are arranged in the order of their hard- 

 ness, under the heads of hardness, gravity, cleavage, lustre, color, 

 diaphaneity, &;c. The second table is independent of crystallization, 

 and is distributed into the three grand classes before named, subdi- 

 vided into sections and subsections depending (with the exception of 

 the individuals of Class I,) on their metallic or unmetallic lustre and 

 their colored or uncolored streak. The species in these several 

 subdivisions are arranged in the order of their hardness, under the 

 heads of hardness, gravity, structure, (including references to the 

 system of crystallization,) lustre, color, diaphaneity, effects of acids 

 and of the blowpipe. The minerals in several of the sections are 



