Leave your cares at the office; prepare your mind for play, and you will feel so much better and stronger and so much more successful in your business. We don't want to hear any more sh-h-h--sh-h-h--or whispers when you come home. We don't want to feel that uncomfortable feeling of restraint; let's laugh and sing and love and play--let's make your home-coming a joyous event. We all love you, Dad, but you haven't made it as comfortable as you might for us when we try to express our love. You've been too tired, too busy, too much occupied with those business thoughts. Don't you see how we love you and how we appreciate you? Don't you know that there is no one in the world who can take the place of Dad? Keep your heart young, Dad; we will help if you only say, "Come on." We are waiting for the signal. Let's start the new schedule tonight. Come on, Dad, what do you say? 36. [Sidenote: What Our Bodies are Composed Of.] We speak of the three kingdoms: the animal, the vegetable and the mineral kingdoms, and every substance is classified into one of these. The exact truth is there is but one kingdom, which is the mineral. The vegetable substances and animal combinations are made of mineral elements. In a rough way we distinguish the mineral kingdom as those substances called elements, such as iron, sulphur, carbon, oxygen, hydrogen, sodium and the like. These elements are unchangeable in themselves; they do not grow. The animal is made of mineral elements associated in certain proportions, such as albumin, carbon, lime, water, salt and the like. The vegetable kingdom also consists of these various chemical combinations. Seed, when planted, extracts the minerals from the air and the earth and combines them into a plant, which grows and has for its object the making of seeds to reproduce and perpetuate itself. The plant has life, but it has no spiritual or mental equipment, and therein vegetable life differs from the animal life. The animal eats vegetable and animal flesh. Through the vegetable he gets the mineral matter necessary for body-building. He also gets a plentiful supply of mineral from the flesh he eats, which flesh was first built up through the vegetables the animal ate. These are definite facts. The human body may be analyzed and separated into something like a dozen substances, among which are water, which is three-fourths of the body's structure, carbon, lime, phosphorus, iron, potassium, salt and so on. By reading a book on anatomy you can learn just exactly the proportions of the substances in the human body. All these chemicals are formed in the shape of little cells, myriads of which are in the body. These cells are constantly being destroyed and new ones made to take their place. Parts of the body are replaced every twenty-four hours; other parts less often. [Sidenote: What Our Bodies Need.]