PARK SANITATION 



833 



Lyster Bag is a water bag made of waterproof canvas, having a capacity 

 of thirty-six gallons (Plate 309). This bag is suspended by ropes from a 

 support and is equipped with one or more faucets at the bottom. Calcium 

 hypochlorite for use in a Lyster Bag can be purchased in one gram (15 

 grains) glass ampules from firms dealing in camping supplies or from chemical 

 companies. The bag is filled with water to the thirty-six gallon mark. If 

 the water is turbid (muddy), it should be strained into the bag through a 

 closely woven cloth stretched across the top. One gram of the calcium 

 hypochlorite is dissolved in a cup of water and the solution added to the 

 thirty-six gallons of water in the bag. The water is then stirred a few 

 times with a clean stick and allowed to stand thirty minutes before using, 

 in order to give the chlorine time to act. Water chlorinated in a Lyster 

 Bag will frequently have a taste which is disliked by some people. This 

 taste is due to compounds formed by the union of the chlorine with organic 

 matter, but the amount of chlorine in the water is so small that it is abso- 

 lutely harmless and cannot possibly injure the health of the consumer. 



If the Lyster Bag is not available, water may be chlorinated in gal- 

 vanized iron containers, or other convenient receptacles, by the addition of 

 one gram (i ampule) of calcium hypochlorite to each thirty-six gallons of 

 water. If only small containers are at hand, water may be purified for 

 drinking purposes by first breaking a one-gram ampule of hypochlorite into 

 one quart of clear water and after thoroughly 

 mixing adding two teaspoonfuls of this strong 

 solution to one quart of drinking water, which 

 must be allowed to stand for thirty minutes 

 before using. 



The Lyster Bag method of treating water 

 or one of its modifications is superior to boil- 

 ing water where the disinfection must be car- 

 ried out by the individual hiker, picnicker or 

 camper, because the chance of neglect or error 

 is less in the former than the latter process. 

 The Lyster Bag method has the disadvantage 

 that the water disinfected by this method is 

 not ordinarily used for cooking. Theoret- 

 ically, cooking should in itself serve to sterilize the water, but quite fre- 

 quently the water is not heated sufficiently to kill all the germs. 



The chlorinating of water used for bathing and swimming is discussed 

 in that section relating to the sanitation of swimming pools (pages 891-898). 



PLATE No. 309 

 LYSTER BAG 



