and let the world in.  So much for the fuel; but God meant something else besides fuel when he packed this closet for his children.  At first they only understood this simplest and plainest value of the coal.  But there were some things that troubled the miners very much:  one was gas that would take fire from their lamps, and burn, making it dangerous for men to go into the passages where they were likely to meet it.  But by and by the wise men thought about it, and said to themselves, We must find out what useful purpose God made the gas for:  we know that he does not make any thing for harm only.  The thought came to them that it might be prepared from coal, and conducted through pipes to our houses to take the place of lamps or candles, which until that time had been the only light.  But, after making the gas, there was a thick, pitchy substance left from the coal, called coal-tar.  It was only a trouble to the gas-makers, who had no use for it, and even threw it away, until some one, more thoughtful than the others, found out that water would not pass through it.  And so it began to be used to cover roofs of buildings, and, mixed with some other substances, made a pavement for streets; and being spread over iron-work it protected it from rust.  Don’t you see how many uses we have found for this refuse coal-tar?  And the finest of all is yet to come; for the chemists got hold of it, and distilled and refined it, until they prepared from the black, dirty pitch lovely emerald-colored crystals which had the property of dying silk and cotton and wool in beautiful colors,—­violet, magenta, purple, or green.  What do you think of that from the coal-tar.  When you have a new ribbon for your hat; or a pretty red dress, or your grandmamma buys a new violet ribbon for her cap, just ask if they are dyed with aniline colors; and if the answer is “Yes,” you may know that they came from the coal-tar.  Besides the dyes, we shall also have left naphtha, useful in making varnish, and various oils that are used in more ways than I can stop to tell you, or you would care now to hear.  If your cousin Annie has a jet belt-clasp or bracelet, and if you find in aunt Edith’s box of old treasures an odd-shaped brooch of jet, you may remember the coal again; for jet is only one kind of lignite, which is a name for a certain preparation of coal.

But here is another surprise of a different kind.  You have seen boxes of hard, smooth, white candles with the name paraffin marked on the cover.  Should you think the black coal could ever undergo such a change as to come out in the form of these white candles?  Go to the factory where they are made, and you can see the whole process; and then you will understand one more of God’s meanings for coal.