THE WORLD BEFORE LIFE. 



5 2 5 



properly belongs ; the waters above are to be separated by the " firma- 

 ment " from the seas beneath. Next, we may observe chemical reac- 

 tions. The condensed steam, in falling through the lower zones, would 

 dissolve the sulphuric and hydrochloric gases, and convert the rain into 

 powerful acids.. When these fall upon the slaggy crust, the excrescences 

 will not only be removed, to be deposited as sediment in the hollows, 

 but a large percentage of the surface will enter into solution, giving 

 rise, not to an acid ocean, but one containing sulphates and chlorides. 

 The more soluble silicates would be converted into chlorides, leaving 

 upon the slaggy floor piles of silica. The sulphates may have been 

 largely of the heavier metals, not excluding the others. 



Fig. 6. 



Primeval Eain. 



Prof. Wurtz thinks the first ocean would be characterized by the 

 predominance of sulphates. Granting this, we can understand the 

 conversion of the sulphates into sulphurets in subsequent periods, as 

 well as into gypsum. Aqueous deposits of sulphurets of copper, iroi^ 

 lead, antimony, etc., are common in Eozoic and Paleozoic strata. The 

 action of carbonic acid must not be overlooked. The liquid acids may 

 have disintegrated the silicates of the alkalies and alkaline earths ; 

 but the compounds of silica, with alumina and iron, are not so easily 

 decomposed. As soon as the carbonic acid could act upon feldspar com- 

 pounds, we should have the potash and soda dissolved out as carbon- 



