Apart from the brain, the ear would be conscious of no sound, whether the soft wash of the waves along the shore, or the mighty roll of the thunder through the sky. On the other hand, none of these voices could reach the brain if God had not "planted the ear," and formed it so perfectly to receive the waves of sound which, striking upon its delicate little "drum," cause it to vibrate, and so are passed on by the nerve which takes messages to the brain. For it is the brain which takes charge of every "impression" conveyed to it by eye, ear, hand, nose, or palate; but _how_ these impressions conveyed to the brain give rise to what we call "thoughts" and "ideas"--this is one of the secret things which belong to God, and of which He has not allowed the wisest man to say, "Oh yes, I understand all about it!" And there is another secret thing which cannot be explained. The heart has been called "the fountain of life," because by it the blood, which is the life of the body, is kept in continual motion, and sent to every part. How little we think of it! But whether we are waking or sleeping, at work or at rest, this busy fountain still goes on playing. We may hear the throb of it, as it strikes against the chest, in its ceaseless working; and we may count these regular "beats," and find that there are about seventy-five of them every minute. It has been calculated that during an ordinarily long life there are three thousand millions of beats without a break. But what has set this fountain at work? and what keeps it going night and day without any thought or care of ours, all our life long? Of all this it can only be said, "We do not know; we cannot find out. God in His wisdom has so ordered it." Many years ago a doctor, who had observed very carefully, and thought much about what he observed, found out that every time the heart beats, the blood rushes from it into a great curved tube called an artery, and so passes through tubes which, like the nerves, are constantly becoming finer and finer, to every part of the body. He also discovered that the blood takes its journey back again to the heart by a different road: it does not return through these tubes, but through softer ones, called veins. Thus far he could go, and the story of the "circulation" of the blood is very interesting; but the _cause_ of the heart's perpetual motion, and the blood's continuous flow, this he could not discover. Is it not wonderful to think that this rapid motion of the fountain within us goes on so noiselessly that even a baby whose little heart has only just begun to beat, is not disturbed by it, as he sleeps in his cradle?