

FLORA. 261 



the mere act of condensation which has been referred to, 

 might suffice to produce a development of heat sufficient 

 to have brought the whole mass into a state of fusion. 



If this did happen, a film of crust would be formed 

 through the cooling of this mass ; and as the process of 

 cooling advanced this crust would become thicker and 

 thicker. By the combination of oxygen with hydrogen, 

 whencesoever these had come, and in what way soever 

 the combination was brought about most probably by 

 fire there came into existence an immense body of 

 water, probably at first in a state of invisible vapour, but 

 thereafter condensed into a state of mist or cloud, and 

 subsequently into a liquid mass constituting the ocean 

 now covering a great extent of the earth's surface, and at 

 places miles deep. By the movements of this, large por- 

 tions of the remaining solid mass mechanically severed, 

 or chemically decomposed, were carried about and ultima- 

 tely deposited ; but at first often to be again fused by 

 the heat of the molten mass enclosed in the crust ; and thus 

 were produced the so-called secondary or transitionary 

 rocks, the gneiss and schist, and metamorphic rocks, the 

 last named rocks to some extent crystallised or otherwise 

 changed by the action of fire. 



The correctness of the opinion that the earth is at 

 present a molten mass of matter enclosed in a solid crust 

 has been called in question. But the granite or primitive 

 rock defies all attempts to penetrate it to any thing like 

 the depth which would enable us to determine the fact 

 by observation and the thickness of this crust, if crust only 

 it be ; though the strata overlying this which have been 

 deposited from water, and afterwards fused, have been so 

 fractured and dislocated that the measurement of the 

 thickness of some of these has been proximately determined. 

 In these are no remains of organic structures of animal or 

 of vegetable origin, nor could such have been expected to 

 survive the fusing heat to which these strata have been 

 subjected; and from the fact mentioned, however it has 

 been brought about, they have been characterised as azoic, 



