BY MARGARET E. DODD, S. B.

In reading many hundreds of test papers written by our students I have found that additional con ments suggest themselves frequently, and it may be of interest to bring them together here.

IMPURITIES IN WATER

By the term impurities, we mean substances out of place. Pure water is oxide of hydrogen, H,O. If water has salt dissolved in it, for instance, the salt is an impurity for the water, though we do not think of salt as being an impure substance in itself. The mineral impuritics in drinking water are seldom a source of danger, although if the amount is large, such water may not "agree" with persons not used to it. Mineral impurities will usually make the water hard, and therefore troublesome for laundry work and to some extent in cooking.

LAUNDRY WORK

Satisfactory water for laundry work must not only be clear and soft but it must be free from iron, from the discoloration due to decaying vegetable matter, clayey soil, and so on. It should also be free from any odor when hot. Muddy water may be cleared more

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or less satisfactorily by filtering it through sand or "by precipitation." In the latter method, dissolve a scant tablespoonful each of alum and borax in a little hot water, and add this amount to each gallon of water used, stirring it in, and allowing it to settle. The alum and borax react to form a cloudy substance which settles to the bottom, carrying the mud with it. The clear water must then be carefully poured or dipped off from the sediment. A siphon is an excellent contrivance for such a use. If a piece of garden hose is used, tie on a piece of wood so that it extends. one or two inches beyond the end, to keep it above the sediment. Weight it with a piece of lead.

When water made hard by carbonate of lime is to be softened, addition of any of the alkalis will soften it, for this reason. These carbonates will not dissolve in water unless it contains carbon dioxide gas in solution. The alkalis added, unite with the gas, and the lime is thereby made insoluble and separated from the water. We do not see it as a rule, for there is in reality, very little of it, and this little separates in very tiny particles. Water which is hard in the clothes boiler frequently causes trouble because of tiny bits of lime which separate from it and make spots upon the clothes.

A spring situated in sandstone rock generally yields soft water because the sandstone is so slightly soluble, but one situated in limestone rock always gives hard water. Limestone is a very common rock,

so many springs are of hard water.

A shallow well

is more apt to yield soft water than a deep one is, and a river has clearer and softer water near its source, where it runs over rocks, and through uncultivated land.

Occasionally where free alkali is added to hard. water, it unites with greasy or oily matter in the garments being washed, and forms dark spots of soap insoluble in water. This is prevented to some extent by addition of a very little turpentine, and boiling such spotted garments in clean suds may dissolve out. the stains if they have formed. This happens so seldom that the use of soda in laundry work (with caution) for softening water is still to be recommended

Washing powders are usually composed for the most part of washing soda, and as they cost more than soda, it is rather better to buy the latter. Moreover, the strength of the alkali may be more accurately judged.

Water varies greatly in hardness, so it is difficult to give exact rules for softening it, though I am often asked for them. In general, for moderately hard water use:

I level tablespoonful of sal soda to i gallon
water.

1⁄2 level tablespoonful of powdered lye to î
gallon water.

I level tablespoonful of borax to 1 gallon
water.

Do not use ammonia with very hot water, for heat liberates the ammonia gas, which is thus lost.

Some students have thus described the use of ashes from hard wood:

Let it
Put

Add a quart or more of water to a quart of ashes. Boil it a few minutes, adding more water if necessary. Then add sufficient water to make a gallon. settle, then pour off the water and strain it. enough of it in the wash water to secure a good suds with soap. The water dissolves the potash (potasSo this is an eco

sium carbonate) from the ashes.

nomical method of getting this alkali.

I have had many interesting letters on the subject of laundry work. Some of the processes described may be new to many of our students.

One writer describes a method of using paraffine in washing. She dissolves a bar of soap in boiling water and adds to it a piece of paraffine almost as large as a walnut. She uses this in making a suds with boiling water in which the clothes are thoroughly boiled for twenty minutes or more, punching them ocassionally. They must be rinsed in several hot waters to ensure the removal of the paraffine, but she claims the clothes will be beautifully white.

A number have advocated the use of kerosene in laundry work, especially with very much soiled articles. Both this and paraffine certainly act upon the oily film which entangles the dirt and thus make the washing easier. The objection to their use is that more

soap and

more hot water and therefore more fuel must be used. Two tablespoonfuls of kerosene in a boiler of soapy water is about the right quantity. In this connection it should be said that when clothes are taken from the boiler, they should be put into tepid water, and pushed well into it, for lying in the air seems to set the dirt, probably because the fibres contract as they cool, so that foreign particles are enclosed in the cloth and cannot fall out into the rinse water.

Kerosene is excellent to use in washing dish towels. Make a strong soap suds, putting in a tablespoonful of oil to a gallon of water. Soap the towels well. and boil them in this suds for half an hour or so. Then wash, rinse and dry them, in the fresh air. Kerosene is somewhat volatile, and its odor will escape in time. When kerosene has been used, the wringer, tubs, etc., will need very careful cleaning to remove any film of oil before it has time to catch dust.

BLUING

There are three kinds of bluing now on the market. The action and disadvantages of Prussian Blue have been described. It gives a better color, however, than either of the other two. A second kind is Ultramarine blue. This, also, is an iron compound, but it does not decompose with alkali. It is what we often buy as the "ball bluing," and is insoluble in water. Water, however, causes it to break up into very