226 
SECOND BOOK. 
WATER.— I. (p. 153). 
Hard and Soft Water- — Spring water is usually hard owing to 
the lime and other mineral substances it contains. Rain water is soft. 
Hard water curdles soap, and does not make soap-suds, and so is not suitable for 
washing. If lime in the water be the cause of the hardness, boiling will get rid of it, 
and deposit it on the sides of the boiler, which is then said to be f urred. 
Animal and Vegetable Impurities: 
1. Water that runs over the surface of the land takes up impurities from 
the decaying vegetation, or from the refuse of houses, cattle-pens, &c. 
2. Or it may be fouled by sewage or house refuse draining into the soil. 
Generally wholesome. 
Sources of Water-supply : 
1. Spring water. 
2. Deep well water. 
3. Upland surface water. 
4. Lake water. 
5. Stored rain water. 'j 
6. Surface water from cultivated land. J 011 ^ 11 ‘ 
7. River water contaminated with sewage. \ 
8. Shallow well water, or pond water. J an g erous - 
Storage Of Water- — Cisterns used for storing water should be 
regularly cleaned. 
Materials for Cisterns: 
Slate is the best. 
Stone or brick (lined with cement) is good. 
Galvanized iron ; also good. 
Wood is bad. 
WATER.— II. (p. 156). 
Water is present in all foods : 
1. In beverages, where it forms by far the largest part of the bulk; as 
coffee, milk, &c. 
2. In solid foods. Thus out of 100 parts we have 74 parts water in 
bananas, nearly 80 in fish, about 70 in lean meat, 50 in fat, 15 in corn -meal, 
and 80 in yam. 
Water in the Body. — Being thus present in foods, water is also 
present in the body, which is built up from foods. 
Thus, bone contains over 80 per cent of water; muscle, 75 per cent; blood and nerve 
matter, nearly 80 per cent. 
In addition, large quantities of water pass through the body from the kidneys, skin, 
and lungs. 
