The importance of cleanliness in all the actions of life is almost too apparent to need mention, were it not that it is so much neglected by many. Not only cleanliness of the skin, the hair, the teeth, the nails, and the clothing is necessary, but also cleanliness in all our habits. By this means we shall avoid many diseases which are entirely due to dirt of various kinds. The old and excellent definition that dirt is matter in the wrong place suggests that it should be removed; and when we remember that this dirt may consist of irritating particles of minerals in the form of dust, or of poisonous chemicals, and, more fatally, of disease germs, we shall be greatly impressed with the necessity of being clean.