78 PRODUCTIVE FARMING 



Put in a strip of blue litmus paper and see the result. Why 

 is it not affected? Draw off a glassful of the lime-water 

 and, after taking a deep breath and holding it for awhile, 

 force the air from the lungs into it through a straw or tube. 

 The milky color resulting shows that there is a union of the 

 lime-water with the carbon dioxide in the breath, and a new 

 substance is formed. If some of the clear lime-water is left 

 open to the air for some time, a white crust will be formed 

 on the top of it in the same way. 



EXERCISE. To Show an Important Plant-food in Ashes. 

 Pour a few quarts of water into a pan of wood ashes and 

 allow it to stand for fifteen minutes. Drain the water out 

 through a loosely woven cloth. Examine the liquid to 

 detect the lye or potash in it. It is soft and slippery to the 

 touch. Place some red litmus paper in the liquid. It will 

 turn blue. This is because the potash is what we call an 

 alkali. 



EXERCISE. Wood Ashes and Sour Soil. Bog soils are 

 often sour and show an acid reaction with litmus paper. 

 Make some soil sour by wetting it with vinegar. See if it 

 turns litmus paper red. Then wet it with "lye water" 

 obtained by letting wood ashes stand in a vessel of wafer. 

 Test with litmus paper. This time it should change to blue. 

 Sour (or acid) soils may be made "sweet" or neutral by 

 spreading wood ashes on them. Fresh or well-stored wood 

 ashes contain both potash and lime, which have several 

 benefits besides correcting acidity of soils. 



EXERCISE. Lime and Sour Soil. Take a sample of sour 

 soil which you have prepared as in the last exercise. Sweeten 

 (or neutralize) it by the application of lime-water prepared 

 by slaking lime in water. Lime is very helpful to bog soils 

 and other soils too rich in humus. 



Barnyard Manure. The use of barnyard manure on 

 farm and garden soils is one of the best ways of improving 

 them. Its benefits are of several kinds. It is a direct food 



