CHAPTER IV. 

 THE TREATMENT OF ALKALI. 



^TT^ o THE average western farmer alkali is the 

 «JL-* greatest bugbear with which he has to con- 

 ^i«l tend in his tillage operations. The soils of 

 the older eastern states are not troubled in 

 this way, and are too often deficient in alkaline salts, 

 for no soil is produdlive when these ingredients are 

 entirely lacking. Chemically considered, alkali is one 

 of a class of caustic bases — soda, potash, ammonia, and 

 lithia — the distinguishing peculiarities of which are 

 solubility in alcohol and water, the power of uniting 

 with oils and fats to form soap, neutralizing, reddening 

 several yellows, and changing reddened litmus to blue. 

 Fixed alkalies are potash and soda. Vegetable alka- 

 lies are known as alkaloids, and volatile alkalies are 

 composed largely of ammonia, so called in distindlion 

 to fixed alkalies. The principal compounds or salts of 

 the alkalies with which soil is impregnated are Glau- 

 ber's salts or sulphate of soda, washing soda or car- 

 bonate of soda, and common salt. In much smaller 

 proportions are found sulphate of potash, phosphate 

 of soda, nitrate of soda, saltpeter, and even carbonate 

 of ammonia. A majority of the last five are recog- 

 nized fertilizers. The most injurious of the three 

 principal salts is the carbonate of soda. Its property 

 of combining with vegetable mold, otherwise known 

 36 



