THE EARTH 139 



ground, but only to volatilise on their way and 

 again ascend. Finally, these little drops reached the 

 surface of the terrestrial scoria, the temperature of 

 the water much exceeding 100°, owing to the enor- 

 mous pressure exercised by the heavy air of these 

 ages ; and the first pool, the rudiment of a great 

 sea, was collected in some fissure of the lava. This 

 pool was constantly increased by fresh falls of 

 water, and ultimately surrounded nearly the whole 

 of the terrestrial crust with a liquid covering ; but 

 at the same time it brought with it fresh elements 

 for the constitution of future continents. The 

 numerous substances which the water held in 

 solution formed various combinations with the 

 metals and solids of its bed ; the currents and 

 tempests which agitated it destroyed its shores, 

 only to form new ones ; the sediment deposited at 

 the bottom of the water commenced the series of 

 rock and strata which follow one another above 

 the primitive crust. 



"Henceforward the igneous planet was exter- 

 nally clothed with a triple covering, solid, liquid, 

 gaseous ; it might therefore become the theatre of 

 life." 



Yet still the moulding of the planet by fire, and 

 water, and ice, went steadily on, and sedimentary 

 rocks fifty miles deep seem to prove that the sea 

 has been at work for over twenty-six million years, 



