4 INTRODUCTION. 



more pretend to decide what it is composed of, than we can tell the' 

 composition of an egg, by probing half way tlu'ough its shell. The 

 internal structure of this orb, allotted for our residence, is knoAvii 

 only to Him who framed it, or t© beings of an order superior to man. 

 "Hast thou entered into the springs of the sea? or hast thou walked 

 in the search of the depth? Have the gates of death been opened 

 unto thee? or hast thou seen the doors of the shadow of death? Hast 

 thou perceived the breadth of the earth ? Declare if thou knowest it 

 all." The more we learn, the more we may be sensible of our igno- 

 rance. If we would fully comprehend any portion of the works of 

 Deity, we must wait till we arrive at a higher sphere of existence. 



Yet we must not abandon our inquiries as hopeless and unprofit- 

 able, because there are limits beyond which we cannot carry them. 

 If we cannot proceed so far as we might wish, let us not stop short 

 in despair, but advance as far as we can : especially as the boundary 

 of our research may prove to be more distant than was at first antici- 

 pated. Phenomena that appeared inexplicable in former ages, are 

 now satisfactorily explained; difficulties once deemed insurmount- 

 able have been overcome ; discoveries have been recently made in the 

 sciences and arts, of which the ancients could have no idea: and 

 who, then, shall define the precise limits of human knowledge, or 

 state the utmost progress which investigation can attain? Geology,; 

 indeed, from the nature of its objects, may seem less likely to be 

 enriched by new discoveries, than most other sciences ; yet who can 

 tell to what a degree of maturity this infant science may at length ,. 

 arrive ? A consciousness of our inability to unvail all the mysteries of 

 nature, in this or in any other department of the creation, should 

 uideed make us modest and humble in conducting our inquiries, but 

 ought not to restrain us from pushing them to the furthest verge of 

 human research. Close investigations of the works of Omnipotence, if 

 pursued with a proper spirit, are so far from savouring of presumption, 



