CARBONATE OF LIME. 137 



stone jug with water will make a sour vinegar, as the 

 writer tested in his ranching days. Soil acids accu- 

 mulate in soils that have no lime to neutralize them. 

 Some plants grow well in sour soils, but not many 

 useful plants. Wild things grow most in acid soils. 

 Useful legumes grow poorly, if at all, with some ex- 

 ceptions. And alfalfa refuses to grow at all with 

 the soil sour. 



How is one to judge if his soil is sour? If he is 

 experienced in soils he can tell by the character of 

 plant growth on the land whether it is sweet or sour. 

 Certain grasses betoken sour lands. Sorrel, or sheep 

 sorrel (Kumex acetosellan) is pretty sure to come 

 where there is lime deficiency, and sorrel and alfalfa 

 do not go well together. There is a simple test that 

 any one can make with litmus paper. This is a blue 

 paper that can be bought of the druggist, usually in 

 little slips, stoppered in glass bottles. One can take 

 a slip of this paper and some of the suspected soil, 

 having it moist, and insert half the length of the 

 slip in the moist soil and let it remain in contact for 

 half an hour. If there is any apparent redness in 

 the paper be sure that there is acidity in that land. 

 If the blue paper does not turn red the land is at 

 least neutral. To test whether the land is actually 

 alkaline with lime, which it ought to be to grow big 

 alfalfa, expose a slip of the paper in quite weak 

 vinegar only long enough to turn it red, then insert 

 it in the soil and leave it for an hour, having the soil 

 moist and in contact. If it then turns blue again 

 you may be sure that you can grow it on that land, 



