Perhaps one of the most disappointing experiences of the novice in housekeeping is the rapidity with which everything assumes a shabby aspect. Bright paint grows dull, dull paint wears away, curtains and fabrics fade, and very soon mistress and maids alike feel that the house no longer repays the trouble incurred in the spring-cleaning that it must still undergo. This spring-cleaning, the primary object of which is the preservation of the beauty and substance of the house and its appointments, is in the result the cause of much of their deterioration. Cleaning consists in removing dirt by means that are partly physical and partly chemical; for instance, the removal of dust by sweeping, shaking, or brushing is a physical operation, and the removal of dirt and grease by dissolving them in soapy water involves their change by a chemical process. If the surfaces or materials to be cleaned include a substance on which the cleansing agent can operate the agent will not confine its work to the removal of the dirt only; in washing coloured fabrics we know how often the colour comes out with the dirt. Knowledge therefore, not only of the composition and properties of cleansing agents, but also of the surfaces and materials to which they are to be applied, is essential, and we should find that it is not always the powder or paste which makes the greatest show of cleanliness in the shortest time, with least expenditure of labour, that is the most to be desired. _The use of alkalies._--The most common cleansing agents are hot water, soap, and soda. Hot water is itself a detergent; that is, it has the power of dissolving dirt. It does not, however, dissolve grease, and all household dirt is more or less greasy, hence we cannot do our cleansing with water only, and we are accustomed to add to it soap or soda.