Javelle
Water

Sulphur

Dioxide Bleaching

oxide from the air, grows damp and the chlorine gas

escapes.

In using bleaching powder, mix one or two teaspoonfuls with a pint of cold water in an earthenware dish. The effective part of the powder will be dissolved, so let the mixture settle, or strain off the liquid through a cloth. Add a little vinegar or a few drops of acetic acid to the nearly clear solution and

use at once.

Javelle water is also used as a bleaching agent. It is very like bleaching powder, except that soda replaces the lime. It is prepared by dissolving one pound of washing soda in a quart of hot water and adding one quarter of a pound of chloride of lime also dissolved in a quart of hot water. Let the mixture settle, pour off the clear liquid and bottle it for use. It will keep for some time. The dregs may be used to scour the kitchen floor or to disinfect waste pipes. This is very useful in removing stains on white cloth, but the addition of some solution to neutralize the action is always necessary, just as with bleaching powder. The best substance to use for this is hypo-sulphite of soda, the "hypo" used in photography, which is quite harmless to the cloth.

Chlorine cannot be used in bleaching fabrics of animal fibre such as wool and silk; it leaves them yellow rather than white. For these the fumes of burning sulphur, or these fumes dissolved in water must be

used. No special means of destroying the excess of sulphur fumes is required. These fumes are a compound of sulphur and the oxygen of the air and familiar to every one, in the acid fumes from a burning "sulphur match." The article to be bleached must be wet, and then hung in some enclosed space above a piece of burning sulphur. The sulphur candles, to be had at any druggist's, are convenient for this use. Fig. 20. The fumes have great affinity for oxygen, that is, unite with it easily, and take it from the coloring stuffs, converting them into colorless ones. This method of bleaching is sometimes not permanent.

These fumes of sulphur are often used to disinfect rooms where there has been sickness. Its power in this respect is far less than is generally supposed however, and much larger quantities of the gas are required for thorough work than are commonly used. Chlorine gas is an excellent disinfectant, but is dangerous to use because of its irritating effect upon the throat and lungs. The use of "chloride of lime" as a disinfectant depends upon the fact that chlorine slowly

Disinfection

Hydrogen
Peroxide

Alkalies on Paint

escapes from this substance when it is exposed to the air.

Another bleaching agent of growing importance is peroxide of hydrogen. Water is a compound made up of one-third oxygen and two-thirds hydrogen. Under certain conditions, a compound half oxygen and half hydrogen may be prepared. This is not very permanent as the extra oxygen slowly escapes. This extra oxygen has great power as a decolorizer. The peroxide is a liquid much like water in appearance and is used in bleaching hair, feathers, and ivory. It is the safest bleaching agent for the housekeeper to work with and may be used on wool and silk as well as cotton and linen.

CLEANING WOODWORK

In the interior of the house woods are seldom used in their natural state. The surface is covered with two or more coatings of paint, varnish, etc., which add to the wood durability or beauty. The cleaning processes are applied to the last coat of finish and must not injure this.

Soft woods are finished with paint, stain, oil, shellac, varnish, or with two or more of these combined; hardwoods with any of these, and in addition, wax, or wax with turpentine, or both with oil.

All these surfaces, except those finished with wax, may be cleaned with a weak solution of soap or ammonia, but the continuous use of any alkali may im

pair and finally remove the polish.

Refinishing will then be necessary. Waxed surfaces are turned dark by water. Finished surfaces should never be scoured nor cleaned with strong alkalies, like sal-soda, or potash soaps. Scouring with these strong alkalies will break the paint or varnish and in this way destroy the finish.

A few drops of kerosene or turpentine on a soft cloth may be used to clean all polished surfaces. The latter cleans them more perfectly and evaporates readily; the former is cheaper, safer, because its vapor is not so inflammable as that of turpentine, and it polishes a little while it cleans; but it evaporates so slowly that the surface must be rubbed dry each time, or the dust will be collected and retained. The harder the rubbing, the higher the polish.

Outside the kitchen, the woodwork of the house seldom needs scrubbing. The greasy layer is readily dissolved by weak alkaline solutions, by kerosene or turpentine, while the imbedded dust is wiped away by the cloth. Polished surfaces keep clean longest. If the finish be removed or broken by deep scratches, the wood itself absorbs the grease and dust, and the stain may have to be scraped out.

CLEANING METALS

Most metals may be washed without harm in a hot alakline solution or wiped with a little kerosene. Stoves and iron sinks may be scoured with the coarser materials like ashes, emery or pumice; but copper, pol

Kerosene

in Cleaning

Tarnish

Silver Sulphide

ished steel, or the soft metals, tin, silver, and aluminum require a fine powder that they may not be scratched or worn away too rapidly. Metal bathtubs may be kept clean and bright with whiting and ammonia, if rinsed with boiling hot water and wiped dry with soft flannel or chamois.

Porcelain or soapstone may be washed like metal or scoured with any fine material.

The special deposits on metals are caused by the oxygen and moisture of the air, by the presence of other gases in the house, or by acids or corroding liquids. Such deposits come under the general head of tarnish.

The metals, or their compounds, in common use are silver, copper and brass, iron and steel, tin, zinc and nickel. Aluminum is rapidly taking a prominent place in the manufacture of household utensils.

There is little trouble with the general greasy film or with the special deposits on articles in daily use, if they are washed in hot water and soap, rinsed well and wiped dry each time. Yet certain articles of food act upon the metal of tableware and cooking utensils, forming true chemical salts.

The salts of silver are usually dark colored and insoluble in water or in any alkaline liquid which will not also dissolve the silver. Whether found in the products of combustion, in food, as eggs, in the paper or cloth used for wrapping, in the rubber band of a fruit jar, or the rubber elastic which may be near the