Yes.

Then his way of taking things to pieces must be a very clumsy one, if he can find out no difference between diamond and charcoal.

Well, perhaps it is:  but you must remember that, though he is very old—­as old as the first man who ever lived—­he has only been at school for the last three hundred years or so.  And remember, too, that he is not like you, who have some one else to teach you.  He has had to teach himself, and find out for himself, and make his own tools, and work in the dark besides.  And I think it is very much to his credit that he ever found out that diamond and charcoal were the same things.  You would never have found it out for yourself, you will agree.

No:  but how did he do it?

He taught a very famous chemist, Lavoisier, about ninety years ago, how to burn a diamond in oxygen—­and a very difficult trick that is; and Lavoisier found that the diamond when burnt turned almost entirely into carbonic acid and water, as blacklead and charcoal do; and more, that each of them turned into the same quantity of carbonic acid, And so he knew, as surely as man can know anything, that all these things, however different to our eyes and fingers, are really made of the same thing,—­pure carbon.

But what makes them look and feel so different?

That Analysis does not know yet.  Perhaps he will find out some day; for he is very patient, and very diligent, as you ought to be.  Meanwhile, be content with him:  remember that though he cannot see through a milestone yet, he can see farther into one than his neighbours.  Indeed his neighbours cannot see into a milestone at all, but only see the outside of it, and know things only by rote, like parrots, without understanding what they mean and how they are made.

So now remember that chalk is carbonate of lime, and that it is made up of three things, calcium, oxygen, and carbon; and that therefore its mark is CaCO(3), in Analysis’s language, which I hope you will be able to read some day.

But how is it that Analysis and Synthesis cannot take all this chalk to pieces, and put it together again?

Look here; what is that in the chalk?

Oh! a shepherd’s crown, such as we often find in the gravel, only fresh and white.

Well; you know what that was once.  I have often told you:—­a live sea-egg, covered with prickles, which crawls at the bottom of the sea.

Well, I am sure that Master Synthesis could not put that together again:  and equally sure that Master Analysis might spend ages in taking it to pieces, before he found out how it was made.  And—­we are lucky to-day, for this lower chalk to the south has very few fossils in it—­here is something else which is not mere carbonate of lime.  Look at it.

A little cockle, something like a wrinkled hazel-nut.