WATER 117 



menace to health. Epidemics of typhoid fever, scarlet 

 fever, and cholera have been traced to drinking water 

 that had become contaminated with the forms that pro- 

 duce these diseases. Our city governments keep a close 

 watch on the water supply to protect the inhabitants 

 from the dangers of polluted water. 



Filtering water is a wise precaution, if one is careful 

 to cleanse the filter frequently, as it reduces the dan- 

 gers from pollution to a minimum. 



When water is under suspicion it is wise to boil it 

 before using. Fifteen minutes' boiling destroys all 

 living forms in the Avater and renders it safe for 

 drinking. True, boiled water has a flat taste, because 

 the air which was held in solution was driven off in 

 the boiling, but this can be overcome partly, at least, 

 by filling sterilized bottles half full with boiled water, 

 and mixing the air and water by shaking. The bottles 

 should then be closed and set in a cool place until 

 ready for use. 



The following method of purifying any drinking 

 water so that it will be safe to drink is given by Dr. 

 W. A. Evans, former Health Commissioner of Chicago : 



"Take a level teaspoonful of chloride of lime and 

 rub it up, until there are 110 lumps, in a teacup of water. 

 Dilute this with three cupfuls of water, and keep this 

 stock solution in a stoppered bottle for use. A tea- 

 spoonful of this stock solution, added to a two-gallon 

 pail of water, and well stirred up, will destroy all 

 typhoid or other dysentery producing germs in ten 



