XVI CQXTKNTS. 



. 22. Simple Mineral . . .22 



. 23. Compound Mineral . , ' 22 



. 24. Mixed Mineral . . . 2.3 



. 25. Division of the Natural-Historical Properties 24 



SECTION I. 



The Natural-Historical Properties of Simple Minerals. 



CHAPTER I. 



. 



Of the Regular Forms of Minerals. 



1. &EXERAL. CONSIDERATION OF THE REGULAR FORMS. 



. 26. Crystal . . . .27 



. 27- Object of Crystallography . . 28 



. 28. Forms and Faces . . .28 



. 29. Edges ... 29 



. 30. Solid Angles . . .29 



. 31. Homologous Faces -. . 29 



. 32. Homologous or Equal Edges . .30 



. 33. Denomination of the Solid Angles . 30 



. 34. Simple and Compound Forms . .31 



. 35. The Compound Forms consist of the Simple 31 



. 36. Tangent Planes . . 32 



. 37. Sections . . .32 



. 38. Homologous Sections . . 33 



. 39. Axes . . . .35 



. 40. Homologous Axes . . 35 



. 41. Principal and subordinate Axes . . 3G 



. 42. Upright Position . . 37 



. 43. Parallel Position , . .37 



. 44. Horizontal Projection . 37 



. 45. Regularity . . .38 



. 46. Degrees of Regularity . 38 



. 47. Determination of the Degrees of Regularity 39 



. 48. Classification of Simple Forms . 40 



. 49. Nomenclature of Simple Forms . . 40 



