XIV TABLE OF CONTENTS. 



Organic matters' in water; their nature and origin .... 152 



Geological relations of mineral waters 153 



Palaeozoic formations of the St. Lawrence basin 154 



Relations of mineral waters to the various formations .... 156 



Contiguity of dissimilar mineral springs 157 



Temperatures of the mineral waters of Canada 157 



Besults of the evaporation of these waters 158 



SUPPLEMENT. 



Waters with a predominance of chloride of calcium 158 



Waters with soluble sulphides; mode of analysis 169 



APPENDIX. 



On the porosity of rocks and its significance 164 



Mode of determining the density and porosity of rocks .... 165 



Table of the density and porosity of various rocks 166 



ON PETROLEUM, ASPHALT, PYROSCHISTS, AND COAL. 



Geological relations of petroleum 168 



Origin and source of petroleum 170 



The oil-bearing limestone of Chicago; its analysis 172 



Large amount of petroleum contained in the limestone .... 178 



Bitumens ; their analyses and chemical composition 176 



Wall on the bitumens of Trinidad and Venezuela 176 



Conversion of organic matters into coals and bitumen .... 177 



Pyroschists or bituminous shales ; their nature defined . . . 177 



Their geological and chemical relations 178 



Chemical similarity of animal and vegetable tissues .... 179 



Note on the constitution and artificial production of albuminoids . . 180 



Dawson on the origin of coal 181 



Comparative analyses of epidermal tissues 181 



On the gaseous hydrocarbons found in nature 182 



XI. 



ON GRANITES AND GRANITIC VEIN-STONES (1871-1872). 



Granite and its varieties defined 184 



The relations of granite to gneiss 186 



Stratiform structure in various erupted rocks 186 



Feldspar-porphyries ; their characters and distribution ... 187 



Granitoid gneisses of New England; true granites 188 



Granitic vein-stones; theories as to their origin 189 



Views of Scheerer, Scrope, and Elie de Beaumont 1 



The concretionary origin of granitic veins 192 



Granitic vein-stones of the White Mountain rocks described . . .104 



Their banded structure; disturbance of the strata by veins ... 196 



