Rain water takes up the dust and gases from the air, and
organic matter from the roofs over which it is collected.
The long storing in a cistern gives bacteria opportunity to
grow in large numbers, causing the water to be unsafe for
drinking purposes.
Springs are a source of pure water supply if they are not
contaminated by passing through soil which is polluted.
Rivers and lakes are a common source of water supply,
but they may be made very unfit for drinking if the surface
water and sewage from towns and cities is allowed to drain
into them.
Surface wells are a very unsafe source of drinking water
supply, and the water should never be used when there are
cesspools, drains, barnyards, or any other sources of contam-
ination within a radius of 200 feet of them.
Deep artesian wells furnish pure water as a rule, unless the
piping is not tightly jointed, when impure water from a
subsoil stream near the surface may enter the pipes.
Methods of Purification of Water. — 1. Boiling. 2. Filtration.
3. Distillation.
Boiling is a certain method of destroying bacteria. If
there is the slightest doubt as to the purity of the water, it
should be boiled for twenty minutes and then be quickly
cooled. It should be put into perfectly clean bottles, tightly
stopped, and be placed on or near the ice.
Filtration. — The modern filter contains a hollow tube of
unglazed porcelain, which is porous and through which the
water percolates slowly. All mechanical impurities of the
water are deposited on the surface of the tube. These im-
purities usually carry the bacteria, which are thus removed.
WATER AND BEVERAGES 117
The tubes should be washed often, and occasionally be re-
moved from the filter to be baked or steamed.
Charcoal is used in many filters, as it removes all color,
odor, and taste from the water by holding back the organic
matter ; but the charcoal may soon become a source of con-
tamination, as bacteria will grow rapidly in the organic
matter present.
Many cities purify the water supply by precipitating the
organic matter present by the addition of iron sulphate,
alum, or calcium hydrate. The bacteria are entangled in the
precipitate, which is then filtered out by mechanical filtra-
tiqn through sand and gravel.
Distillation is the process of condensing steam. The
water thus obtained is the only chemically pure water.
Ice. — Freezing has little effect upon bacteria except to
lessen temporarily their vitality. When the ice melts, the
bacteria may again become active. Ice made by artificial
means from distilled water is the only pure ice. For cooling
drinking water, the water should be placed on the ice and
the ice should not be put into the water.
Hard and Soft Water. — Soft water is water in which no
mineral matter is dissolved. Hard water is water in which
such minerals as lime, magnesium, and iron are dissolved.
Boiling precipitates some of the mineral matter, thus tend-
ing to soften the water. This mineral deposit may be seen
on the inside of a teakettle. Hard water that is to be used
for cleansing purposes may be softened by the addition of
washing soda, borax, ammonia, potash, or soda lye.
BEVERAGES
Pure water ranks as the first and most important of
beverages. An adult should drink about three pints of
water a day. Tea and coffee are stimulants, furnishing
118 DOMESTIC SCIENCE
Page 50
Presented as published in 1913. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
AI-modernized reading of the original text
Rain water takes up the dust and gases from the air, and organic matter from the roofs over which it is collected. The long storing in a cistern gives bacteria opportunity to grow in large numbers, causing the water to be unsafe for drinking purposes.
Springs are a source of pure water supply if they are not contaminated by passing through soil which is polluted.
Rivers and lakes are a common source of water supply, but they may be made very unfit for drinking if the surface water and sewage from towns and cities is allowed to drain into them.
Surface wells are a very unsafe source of drinking water supply, and the water should never be used when there are cesspools, drains, barnyards, or any other sources of contamination within a radius of 200 feet of them.
Deep artesian wells furnish pure water as a rule, unless the piping is not tightly jointed, when impure water from a subsoil stream near the surface may enter the pipes.
Methods of Purification of Water. — 1. Boiling. 2. Filtration. 3. Distillation.
Boiling is a certain method of destroying bacteria. If there is the slightest doubt as to the purity of the water, it should be boiled for twenty minutes and then be quickly cooled. It should be put into perfectly clean bottles, tightly stopped, and be placed on or near the ice.
Filtration. — The modern filter contains a hollow tube of unglazed porcelain, which is porous and through which the water percolates slowly. All mechanical impurities of the water are deposited on the surface of the tube. These impurities usually carry the bacteria, which are thus removed.
The tubes should be washed often, and occasionally be removed from the filter to be baked or steamed.
Charcoal is used in many filters, as it removes all color, odor, and taste from the water by holding back the organic matter ; but the charcoal may soon become a source of contamination, as bacteria will grow rapidly in the organic matter present.
Many cities purify the water supply by precipitating the organic matter present by the addition of iron sulphate, alum, or calcium hydrate. The bacteria are entangled in the precipitate, which is then filtered out by mechanical filtratiqn through sand and gravel.
Distillation is the process of condensing steam. The water thus obtained is the only chemically pure water.
Ice. — Freezing has little effect upon bacteria except to lessen temporarily their vitality. When the ice melts, the bacteria may again become active. Ice made by artificial means from distilled water is the only pure ice. For cooling drinking water, the water should be placed on the ice and the ice should not be put into the water.
Hard and Soft Water. — Soft water is water in which no mineral matter is dissolved. Hard water is water in which such minerals as lime, magnesium, and iron are dissolved. Boiling precipitates some of the mineral matter, thus tending to soften the water. This mineral deposit may be seen on the inside of a teakettle. Hard water that is to be used for cleansing purposes may be softened by the addition of washing soda, borax, ammonia, potash, or soda lye.
BEVERAGES
Pure water ranks as the first and most important of beverages. An adult should drink about three pints of water a day. Tea and coffee are stimulants, furnishing