But how do they turn Coprolites into manure? I used to see them in the railway trucks at Cambridge, and they were all like what I have at home--hard pebbles.
They grind them first in a mill. Then they mix them with sulphuric acid and water, and that melts them down, and parts them into two things. One is sulphate of lime (gypsum, as it is commonly called), and which will not dissolve in water, and is of little use. But the other is what is called superphosphate of lime, which will dissolve in water; so that the roots of the plants can suck it up: and that is one of the richest of manures.
Oh, I know: you put superphosphate on the grass last year.
Yes. But not that kind; a better one still. The superphosphate from the Copiolites is good; but the superphosphate from fresh bones is better still, and therefore dearer, because it has in it the fibrine of the bones, which is full of nitrogen, like gristle or meat; and all that has been washed out of the bone-earth bed ages and ages ago. But you must learn some chemistry to understand that.
I should like to be a scientific man, if one can find out such really useful things by science.
Child, there is no saying what you might find out, or of what use you may be to your fellow-men. A man working at science, however dull and dirty his work may seem at times, is like one of those "chiffoniers," as they call them in Paris--people who spend their lives in gathering rags and sifting refuse, but who may put their hands at any moment upon some precious jewel. And not only may you be able to help your neighbours to find out what will give them health and wealth: but you may, if you can only get them to listen to you, save them from many a foolish experiment, which ends in losing money just for want of science. I have heard of a man who, for want of science, was going to throw away great sums (I believe he, luckily for him, never could raise the money) in boring for coal in our Bagshot sands at home. The man thought that because there was coal under the heather moors in the North, there must needs be coal here likewise, when a geologist could have told him the contrary. There was another man at Hennequin's Lodge, near the Wellington College, who thought he would make the poor sands fertile by manuring them with whale oil, of all things in the world. So he not only lost all the cost of his whale oil, but made the land utterly barren, as it is unto this day; and all for want of science.