OF ORGANIC NATURE. 31 



the historical student is cleared out of our path, there 

 are other difficulties — difficulties in rightly inter- 

 preting the facts as they are presented to us — which 

 may be compared with the greatest difficulties of any 

 other kinds of historical study. 



What is this record of the past history of the globe,, 

 and what are the questions which are involved in an 

 inquiry into its completeness or incompleteness? That 

 record is composed of mud ; and the question which we 

 have to investigate this evening resolves itself into a 

 question of the formation of mud. You may think, per- 

 haps, that this is a vast step — of almost from the sublime 

 to the ridiculous — from the contemplation of the history 

 of the past ages of the world's existence to the con- 

 sideration of the history of the formation of mud ! 

 But, in nature, there is nothing mean and unworthy of 

 attention ; there is nothing ridiculous or contemptible 

 in any of her works ; and this inquiry, you will soon 

 see, I hope, takes us to the very root and foundations 

 of our subject. 



How, then, is mud formed? Always, with some 

 trifling exception, which I need not consider now — 

 always, as the result of the action of water, wear- 

 ing down and disintegrating the surface of the 

 earth and rocks with which it comes in contact — 

 pounding and grinding it down, and carrying the par- 

 ticles away to places where they cease to be disturbed 

 by this mechanical action, and where they can subside 

 and rest. For the ocean, urged by winds, washes, 

 as we know, a long extent of coast, and every wave, 

 loaded as it is with particles of sand and gravel as it 

 breaks upon the shore, does something towards the dis- 



