The Importance of House Cleaning - Methods in General Use - Why Spring Cleaning is Necessary - Substances Used in Cleaning - Soap - The Best Kinds of Soap - Other Detergents and their Uses

- Bleaching Substances

Whether it be regarded as an aid to sanita-tion, or as a concession to our comfort, house-cleaning is a subject of the greatest interest and significance to the housewife.

A review, therefore, of the best methods by which its processes are accomplished will be of both interest and practical value. Cleaning Methods

The adequate removal of dust and dirt calls for knowledge of a special kind. The cleaning method must be adapted to the place and object to be cleaned. Imperfect methods may not only fail to remove the dirt, but they may result in injury to the things cleaned.

Cleaning may be a mechanical or a chemical process, a dry or a wet one. The expert in such matters will know exactly which method to apply. A study of the various modes of cleaning available, and their suitability in various circumstances, is time well spent, and will repay the student. The subject, therefore, will be treated fully from every standpoint of interest and service to the housewife.

Effective cleaning should be a continuous process, a process conducted at short intervals, and so thorough in its preparations that as little as possible is left over to accumulate for the annual spring cleaning. This latter, in certain circumstances, however, is imperative, as, for instance, after workmen have been in to renew the decorations. This work is more generally and most conveniently done in the early part of the year, when fires are being discontinued and fogs have ceased to invade the home. Even when skilfully and carefully done, it results in the importation of much dust and dirt into the rooms, and this has to be removed.

The exit of these useful and necessary men may be taken as the signal for a general cleaning and sweetening of the rooms, and, be it added, for a general overhaul of our belongings.

At such times it may be considered whether certain pieces of upholstery should not be re-covered, and others discarded for new. The backs and lower concealed parts of heavy pieces of furniture may be examined and cleaned. Pictures may be taken from their frames and treated to a cleaning process. Carpets and curtains will be sent to the cleaners, and the sweep will be requisitioned to clean the chimneys of the winter's accumulation of soot.

Spring cleaning, however, can never be an efficient substitute for constant periodical cleansing, for its results cannot possibly persist for more than a limited time.

The Chemistry Of Cleaning

Soap is a combination of fats with alkalies, the latter being either soda or potash. The fat reduces the strength of the alkali, whilst the alkali renders the fat soluble in water. All new soaps contain a quantity of water, and in cheap soaps this quantity is very large.

The salts of lime contained in ordinary spring or tap water, which give it that quality of "hardness," combine with soap to form insoluble matter, which is useless in the cleansing process, and represents so much waste. Hence the economy of using rainwater, which contains no such salts.

Boiling is the only practicable method of rendering hard water useful for detergent purposes. Boiling, however, only eliminates a part of the lime, and therefore boiled water is less economical than naturally soft water.

The great value of soap is its power of combining with grease, and rendering the latter soluble. But soap has also a mechanical action on ordinary dirt; it gathers it up, thus facilitating its removal.

The best quality soaps are the cheapest, because the buyer does not pay for so much water and useless chemicals.

Among other chemical cleaning substances may be mentioned soda, potash, and borax. These all act by reason of their alkaline nature, and are more powerful as solvents of greasy matter than the soaps, though they are less desirable, because of their caustic action on the hands. Their complete solubility in hard water, however, is an advantage. The many "soap powders" and "dry soaps" advertised are mostly forms of borax, or borax in combination with soda.

Potash is the most powerful of these alkalies, and is unsuitable for household use, except in special circumstances, when precautions must be taken to avoid injury to the hands. In combination with fish oil, it forms the well-known soft-soap.

There are other chemical cleaning processes in which such solvents as benzoline, turpentine, and other liquids are employed. These are specially applicable to fabrics, and will be further noticed in due course.

The acids, more particularly sulphuric and hydrochloric acids in dilute form, are useful in removing stains and deposits which will not yield to the alkaline detergents, and act either by dissolving such deposits, or by slightly dissolving the surface to which they are attached, and thereby loosening them. The cleaning of marble, for instance, is conducted by the careful use of a dilute acid. Great care must be exercised in the use of acids. They must be kept in poison bottles, plainly labelled.

Lastly, there are the bleaching substances, which are used to remove stains. Chloride of lime and oxalic acid (salts of lemon) are those most commonly employed. Their action is purely chemical, and they are adapted solely for restoring the whiteness of chemically discoloured substances, and are not suitable for the removal of attached dirt.

The great value of oxalic acid is that it discharges the well-known "ironmould" stains, produced by ink or contact with rusting iron. To be continued.