Even a child's common sense shows him that those two laths were not always so nailed together; that those two bricks were not always so placed, one on the top of the other; and that those two pieces of old sole leather were not always pegged together in the sole of a boot." There is no conviction more irresistible than our belief that _no compound can possibly be eternal_.
But the universe is the greatest of all compounds.

Everything in it is compound.

Chemists speak of simple substances, or elements of matter, and it is well enough to separate the elements of things in our thoughts, for the sake of distinct consideration, and to speak of the properties of pure oxygen, or of pure hydrogen, or of pure carbon, or of pure gold, or of pure iron, or of pure silver.

But then we should always remember that there is nothing pure in the world, that there is no such thing in nature as any substance consisting only of a single element, pure and uncombined with others.

Just as your gold eagle is not pure gold, but alloyed with copper, everything in nature is alloyed.
Everything in the heavens above, and in the earth beneath, and in the waters under the earth, is compound.