ix.] ON A PIECE OF CHALK. 153 



formation of some of the most venerable of mountain ranges, 

 such as the Lebanon. 



What is this wide-spread component of the surface of the 

 earth ? and whence did it come ? 



You may think this no very hopeful inquiry. You may 

 not unnaturally suppose that the attempt to solve such prob 

 lems as these can lead to no result, save that of entangling the 

 inquirer in vague speculations, incapable of refutation and of 

 verification. 



If such were really the case, I should have selected some 

 other subject than a &quot; piece of chalk &quot; for my discourse. But, in 

 truth, after much deliberation, I have been unable to think of 

 any topic which would so well enable me to lead you to see how 

 solid is the foundation upon which some of the most startling 

 conclusions of physical science rest. 



A great chapter of the history of the world is written in the 

 chalk. Few passages in the history of man can be supported 

 by such an overwhelming mass of direct and indirect evidence 

 as that which testifies to the truth of the fragment of the 

 history of the globe, which I hope to enable you to read, with 

 your own eyes, to-night. 



Let me add, that few chapters of human history have a more 

 profound significance for ourselves. I weigh my words well 

 when I assert, that the man who should know the true history 

 of the bit of chalk which every carpenter carries about in his 

 breeches-pocket, though ignorant of all other history, is likely, if 

 he will think his knowledge out to its ultimate results, to have a 

 truer, and therefore a better, conception of this wonderful uni 

 verse, and of man s relation to it, than the most learned student 

 who is deep-read in the records of humanity and ignorant of 

 those of Nature. 



The language of the chalk is not hard to learn, not nearly so 

 hard as Latin, if you only want to get at the broad features of 

 the story it has to tell; and I propose that we now set to work 

 to spell that story out together. 



