"A diamond is nothing but carbon," remarked Johnny; "and charcoal is carbon too. I will give papa a piece of charcoal to wear." "Ho, ho!" laughed Felix: "that’s a yarn! A diamond is just as different from charcoal as possible!" "How?" asked Johnny. "Why, it’s white, and charcoal is black; it’s transparent, and charcoal isn’t; it won’t rub off, and charcoal will; it won’t burn up like charcoal, and it’s worth no end of times more." "But they are both carbon just the same; and those lozenges you are eating are principally carbon, too, although they are a good deal whiter than charcoal. You haven’t any idea how much charcoal you are eating, when you eat sugar or candy. There isn’t any particular difference between the whitest of sugar and charcoal, except that the particles are so arranged as to reflect or absorb light differently. I can take a handful of white sugar, and, by putting in something to change the arrangement of the particles, make it look as much like charcoal as it is, just as black as your boot, and spread out into a great deal larger space than it occupied before." "Yes, he can," said Sue: "I’ve seen him do it." "Well, I’d like to see him do it, before I believe it." "I’ll do it when we get home, to-night, if you will give me five cents, and papa will get me some acid to do it with, when he goes into town. The kind of acid I want will cost five cents." "All right! here’s your five cents," replied Felix, taking the amount from his pocket-book. "After you have seen it proved that sugar is like charcoal, perhaps you can believe more easily that a diamond is. The particles of carbon in a diamond are packed very closely together, and in such a way as to reflect the rays of light beautifully, and separate them like a prism, when it is cut right. It is so hard, that it is not easy to burn it,—that is, to separate the particles by heat, and make them combine with the oxygen in the air,—but it will burn up if subjected to very strong heat indeed. There’s no danger of your diamond burning up, though, Julia, even though you should drop it into the fire by accident; for a fire in a stove wouldn’t be hot enough." "I’m glad of that," replied Julia. "I don’t see as chemistry does so very much good," remarked Felix: "it only tells you about things; it don’t make any thing." "O Felix!" exclaimed Johnny: "there are hardly any of the arts that can be carried on without chemicals, or things chemists have learned how to make; and some of the most useful discoveries in the world have been made by chemists." "Tell him about the way they learned how to make Bessemer steel out of common iron, as an example, Johnny," said Pierre.