X CONTENTS. 



VI. VEINS THEIR NATURE AND ORIGIN. 



VEINS AND DYKES, HOW OCCASIONED METALLIFEROUS VEINS, 

 MOST ABUNDANT IN THE PRIMARY ROCKS REASON OF 

 THIS ABUNDANCE GENERAL CHARACTERISTICS OF VEINS 

 VARYING NATURE OF THE MINERAL SUBSTANCES BY 

 WHICH VEINS ARE MAINLY FILLED MODE IN WHICH THESE 

 VEIN-STGFFS ARE AGGREGATED RELATIONS OF THE ORES 

 TO THE VEIN-STUFFS DIRECTION OF VEINS IN CERTAIN 

 LOCALITIES RIGHT-RUNNING AND CROSS VEINS THEORIES 

 OF FORMATION AND FILLING INFILTRATION AND DEPO- 

 SITION OF CHEMICAL SOLUTIONS EFFECTS OF THERMAL 

 AGENCY ELECTRIC AND OTHER KINDRED CURRENTS RE- 

 LATIONS TO CENTRES OF IGNEOUS ACTION IMPORTANCE OF 

 METALLIFEROUS VEINS CONTRAST BETWEEN THE MINERAL 

 AND AGRICULTURAL VALUE OF PRIMARY DISTRICTS MINES 

 AND STREAM-WORKS, . . . . .101 



VII. FOSSILS-THEIR NATURE AND ARRANGEMENT. 



THE TERMS FOSSIL AND SUB-FOSSILSCIENCE OF PALEONTOLOGY 

 FOSSILS, HOW IMBEDDED AND PRESERVED THEIR IM- 

 PORTANCE IN GEOLOGY INDICATORS OF GEOGRAPHICAL 

 CONDITIONS IN THE PAST OF NATURE AND KIND OF LIFE 

 DURING SUCCESSIVE PERIODS OF WORLD-HISTORY DIFFI- 

 CULTIES ATTENDING PAL.EONTOLOGICAL RESEARCH ORGAN- 

 ISMS MOST PERFECTLY PRESERVED PROCESSES OF PETRI- 

 FACTION CONDITIONS IN WHICH FOSSILS USUALLY OCCUR 

 REQUISITE SKILL FOR THEIR INTERPRETATION BOTANI- 

 CAL AND ZOOLOGICAL ARRANGEMENT OF THIS PRELIMI- 

 NARY KNOWLEDGE NECESSARY TO THE STUDY OF GENERAL 

 GEOLOGY, ...... Ill 



VIII. THE OLD RED SANDSTONE. 



INTEREST ATTACHED TO THE SYSTEM FROM THE LABOURS OF AG- 

 ASSIZ, HUGH MILLER, AND OTHERS ITS POSITION IN WORLD- 

 HISTORY NATURE OF ITS STRATA HOW FORMED LOWER, 

 MIDDLE, AND UPPER FORMATIONS TERRAQUEOUS ASPECTS 

 OF THE PERIOD ITS FLORA AND FAUNA GIGANTIC CRUS- 

 TACEA VARIED AND ABUNDANT FISH-REMAINS GEOGRA- 

 PHICAL OR EXTERNAL CONDITIONS OF THE OLD RED ERA 

 ECONOMIC PRODUCTS DERIVED FROM THE SYSTEM GENERAL 

 REVIEW, ...... 129 



