Ingrain and other carpets, after shaking, are brightened in color by sprinkling a pound or two of salt over the surface, and sweeping carefully; and it is also useful to occasionally wipe off a carpet with borax-water, using a thick flannel, and taking care not to wet, but only dampen the carpet. Mirrors can be cleaned with whiting. Never scrub oil-pictures: simply wipe with a damp cloth, and, if picture-cord is used, wipe it off to secure against moths. It is impossible to cover the whole ground of cleaning in this chapter. Experience is the best teacher. Only remember that a household earthquake is not necessary, and that the whole work can be done so gradually, quietly, and systematically, that only the workers need know much about it. The sense of purity transfused through the air and breathing from every nook and corner should be the only indication that upheaval has existed. The best work is always in silence. CHAPTER VII. THE BODY AND ITS COMPOSITION. "The lamp of life" is a very old metaphor for the mysterious principle vitalizing nerve and muscle; but no comparison could be so apt. The full-grown adult takes in each day, through lungs and mouth, about eight and a half pounds of dry food, water, and the air necessary for breathing purposes. Through the pores of the skin, the lungs, kidneys, and lower intestines, there is a corresponding waste; and both supply and waste amount in a year to one and a half tons, or three thousand pounds. The steadiness and clear shining of the flame of a lamp depend upon quality, as well as amount of the oil supplied, and, too, the texture of the wick; and so all human life and work are equally made or marred by the food which sustains life, as well as the nature of the constitution receiving that food. Before the nature and quality of food can be considered, we must know the constituents of the body to be fed, and something of the process through which digestion and nutrition are accomplished. I shall take for granted that you have a fairly plain idea of the stomach and its dependences. Physiologies can always be had, and for minute details they must be referred to. Bear in mind one or two main points: that all food passes from the mouth to the stomach, an irregularly-shaped pouch or bag with an opening into the duodenum, and from thence into the larger intestine. From the mouth to the end of this intestine, the whole may be called the alimentary canal; a tube of varying size and some thirty-six feet in length. The mouth must be considered part of it, as it is in the mouth that digestion actually begins; all starchy foods depending upon the action of the saliva for genuine digestion, saliva having some strange power by which starch is converted into sugar. Swallowed whole, or placed directly in the stomach, such food passes through the body unchanged. Each division of the alimentary canal has its own distinct digestive juice, and I give them in the order in which they occur.