TABLE OF CONTENTS. xiii 



Action of bicarbonate of soda on calcareous and magnesian salts . . 105 



Origin of sulphates in natural waters . . . . . . . 106 



Indifference of gypsum solutions to dolomite 106 



Decomposition of gypsum by hydrous magnesian carbonate . . 107 



Results of the gradual evaporation of sea-water 107 



Composition of the ancient seas 108 



Separation of the lime salts from sea-water ...... 109 



Decomposition of sulphate of magnesia by bicarbonate of lime . . 109 



Twofold origin of gypsum 110 



Twofold origin of magnesian carbonate 110 



Sulphuric and hydrochloric acid in waters . . . . . .111 



Carbonic acid in waters 112 



Ammonia and nitrogen in rocks and waters 113 



Classification of natural waters 113 



PART II. ANALYSES OF VARIOUS NATURAL WATERS. 



Waters of the first class or bitter salines ; analyses 116 



Their resemblance to bitterns ; absence of sulphates .... 117 



Predominance of chlorides of calcium and magnesium .... 118 



Probable constitution of the Cambrian ocean ..... 119 



Brines of ancient saliferous deposits 119 



Note on analyses of saline waters 120 



Silicate of magnesia; its formation and chemical relations . . . 122 



Waters of the second and third classes ; analyses ..... 123 



Waters of the fourth class or alkaline waters ; analyses .... 125 



Waters of the Ottawa River; analysis 126 



Variations in the composition of mineral springs ..... 127 



Comparative analyses of the Caledonia waters 129 



Sulphuric-acid springs of New York and Ontario 130 



Neutral sulphated waters; their sources 132 



Sulphate of magnesia in waters 134 



PART III. CHEMICAL AND GEOLOGICAL CONSIDERATIONS. 



Salts of the alkaline metals in natural waters 135 



Salts of calcium and magnesium ; relations of chlorides and carbonates . 137 



Results of evaporation ; deposition of carbonates of lime and magnesia 138 



Solubility of carbonate and bicarbonate of lime 139 



Supersaturated solutions of carbonates of lime and magnesia . . 140 



Salts of barium and strontium in waters ....... 141 



Iron, manganese, alumina, and phosphates in waters .... 142 



Bromides and iodides in waters . . . ' . . . . . 142 



Relations of chlorides and iodides to earthy minerals .... 143 



Sulphates in natural waters; their frequent absence .... 144 



Soluble sulphides in natural waters 145 



Borates ; waters of a borax-lake 146 



Carbonates ; studies of the Caledonia waters 147 



Waters with a deficiency of carbonic acid 149 



Silica ; its amount in various waters 150 



Silicates of lime and magnesia deposited from waters .... 151 



