xiv Table of Contents. 



PAGE 



CLEAVAGE 56 



takes place in the direction of the natural 



joints of crystals 56 



different sets of cleavages 56 



the mutual relation of the solids obtained 



by cleavage 59 66 



DECREMENTS. 



simple, mixed, and intermediary .... 67 73 



causes producing these not understood 73 



influenced by the pyroelectricity of bodies . . 76 



SYMMETRY, its laws 77 



PRIMARY FORMS 79 



may sometimes be developed by cleavage 79 

 frequently require secondary forms to 



determine them 81 



SECONDARY FORMS 86 



HEMITROPE & INTERSECTED CRYSTALS 88 



EPICENE & PSEUDOMORPHOUS CRYSTALS 93 



ON THE TABLED OF MODIFICATIONS < 95 



TABLES OF MODIFICATIONS OF 



the cube , 106 



regular tetrahedron 112 



regular octohedron 116 



rhombic dodecahedron 120 



octahedron with a square base 1 26 



rectangular base 138 



rhombic base 146 



right square prism 162 



rectangular prism 166 



rhombic prism 170 



oblique-angled prism 176 



oblique rhombic prism 180 



doubly oblique prism 1 90 



hexagonal prism 1 96 



rhomboid 200 



TABLES OF SECONDARY FORMS 214 222 



ON THE APPLICATION OF THE TABLES OF MODIFICATIONS 223 



method of discovering the forms of crystals, or 

 of reading (hem 223228 



method of describing crystals by means of the 

 tables 229 



ON THE USE OF SYMBOLS FOU DESCRIBING THESECONBARY 



FORMS OF CRYSTALS 233 252 



ON THE RELATION OF THE LAWS OF DECREMENT TO THE 



DIFFERENT CLASSES OI MODIFICATIONS . , . 253 



