74 



Agricultural Chemistry. 



Analyses, quoted from Ingle, of typically good and bad drink- 

 ing waters, are given below. 



Composition of Good and Bad Drinking Waters. 



By hardness is meant the parts of calcium carbonate equivalent 

 to the total amount of calcium and magnesium salts present in 

 one million parts of the water. 



By albuminoid ammonia in the above table is meant the quan- 

 tity of ammonia, which is evolved from the water by the decom- 

 position of organic nitrogenous substances when distilled with 

 an alkaline solution of potassium permanganate. 



Surface water. Rivers, ponds and lakes belong to this class. 

 Most rivers originate in springs, so at first their water resembles 

 that of their source. A considerable influx of surface water, 

 however, generally enters the river and alters its composition. 

 The composition of the waters of ponds or lakes will be much like 

 that of the creeks and rivers flowing into them. The surface 

 water usually contains less dissolved matter than spring water, 

 but often more organic matter and suspended particles. The 

 composition of the river water depends greatly upon the char- 

 acter of the rocks from which it is collected. When the surface 

 consists of igneous rocks or of sandstone, the water is usually 

 soft, while in lime stone districts it will be hard. Some rivers, 

 as for example the Trent of England, are rich in calcium sul- 

 phate and to this fact the excellence of the Burton ales has been 



