PROJECTS 631 



PROJECT LII. How to Clarify and Purify Water for Home 

 Use, page 448 



Water may be murky in appearance without being unwholesome ; 

 on the other hand it may be clear without being pure. But clear 

 water is at least inviting. If a water-filter is used to clarify water, 

 it should be thoroughly cleansed at least once a week preferably 

 oftener. To remove heavy sediment, where a filter is not used, 

 water may be strained through a flannel bag. Small flannel bags 

 with running strings may be fastened on the faucets. These should 

 be changed daily. Wash the used bags with soap and water and 

 hang in the sun to dry. 



Water that contains organic substances may be clarified with the 

 use of alum. The alum coagulates albuminous substances, much 

 as boiling coagulates the white of an egg. This coagulated albu- 

 men settles to the bottom and acts like a net in carrying down other 

 impurities with it. 



A lump of alum suspended by a string and swung about in 

 a pitcher for a minute or so will clarify it. 



A teaspoonful of powdered alum will clarify 4 gallons of water. 

 Stir the water vigorously before adding the alum. Allow the 

 impurities to settle and then draw the water in such a way as not 

 to disturb the sediment. The alum, if there is not too much used, 

 will settle with the sediment. 



To purify contaminated water, boil it for 16 minutes. This 

 drives off the air and makes water taste flat. To restore the 

 sparkle, pour the water rapidly from one vessel to another several 

 times. This aerates the water. A few drops of lemon juice add 

 surprisingly to the palatability of boiled water. 



PROJECT LIU. How Boy Scouts Filter and Purify Water 

 for Drinking, page 448 



The methods applied in the home purification of water may be 

 used by Boy Scouts in field or camp. Run no risks whatever with 

 the water you drink. If you are going for a day's tramp and are 



