Xll TABLE OF CONTENTS. 



Source of heat in plutonic phenomena 77 



The notion of its chemical origin untenable 77 



Henry Wurtz on a mechanical source of heat. 78 



Experiments and conclusions of Mallet 78 



His views on the origin of volcanic products 79 



VIII. 



ON LIMESTONES, DOLOMITES, AND GYPSUMS (1858-1866). 



Introductory note ; letter to Elie de Beaumont 80 



Cordier's views of the origin of limestones and dolomites ... 81 



Their identity with those of the author 82 



Chemistry of evaporating lakes and sea-basins 83 



Alkaline waters of rivers and springs 84 



Separation of lime-salts from sea-water: gypsum and rock-salt . . 85 



Origin of sulphuretted hydrogen and native sulphur .... 87 



Origin of deposits of magnesian limestones ...... 88 



Their deposition necessarily in isolated basins 88 



Hall on the organic remains in magnesian limestones .... 88 



Deposits of pure carbonate of lime ........ 89 



Generation of dolomite; its crystallization 89 



Note on chemically deposited silica 89 



Conclusions as to the chemistry of gypsum and dolomite ... 90 



Conditions of temperature for the production of dolomite . ... 91 



Relative solubilities of gypsum and magnesian bicarbonate . . 91 



Influence of carbonic acid on the formation of gypsum .... 91 



Geographical and climatic conditions for the production of dolomite . 91 



Recent conclusions of Ramsay as to magnesian limestones ... 92 



IX. 



THE CHEMISTRY OF NATURAL WATERS. 



PART I. GENERAL PRINCIPLES. 



Atmospheric waters and the result of vegetable decay .... 94 



Action of waters on the soil; researches of Way and Voelcker . . 96 



Eichhorn on the replacement of protoxide bases in silicates ... 96 



.<> relations of saline waters to the soil 97 



IN.'hit ions of organic matters to oxides of iron and manganese . . 98 



Solution and deposition of alumina 98 



Origin of sulphuretted hydrogen and sulphurets 99 



Decomposition of silicates; studies of Ebelmann 100 



Kanlinization of feldspars and other minerals 101 



Hfl.it ion of soda and potash salts to sediments 101 



Carbonic acid and water as agents in decomposing rocks . . . 12 



Marine salts in solution in sedimentary strata 



Porous nature of sandstones and dolomites 103 



Calculations as to the volume of waters held in rocky strata . . .104 



Solid salts and bitterns from sea-water in the rocks .... 105 



