FARM MANAGEMENT 37 



nitrates and only minute quantities of free and albuminoid am- 

 monia. Heavily manured fields in the vicinity of a spring may 

 cause the presence of nitrates and nitrites as well as an increase of 

 chlorine in the water, because there is often a larger supply of them 

 than the crops can handle, and they are easily leached from the up- 

 per layers of soil beyond the reach of plant-roots. Leaves or sawdust 

 not uncommonly to be found in springs, are pretty sure to increase 

 the amount of albuminoid ammonia above what it would be if the 

 spring were clean.^-(N. H. C. B. 53.) 



If springs are depended upon, the spring should be properly 

 cared for to prevent surface water from flowing into it, and keep out 

 leaves and other rubbish. If walled with brick and concrete an 

 excess of lime is likely to occur, and a high percentage of solid 

 residue. 



Wells. Water from very deep wells which get their supply 

 from strata of soil below the influence of local surface impurities 

 show a difference somewhat in composition from the waters of un- 

 polluted springs. Some wells as well as springs are seriously con- 

 taminated with iron, though the water is otherwise good. Such 

 water is usually clear when freshly drawn from the well, but in 

 exposure to the air it soon becomes opalescent, due to the changes 

 taking place in the iron salts by which insoluble compounds are 

 formed, sometimes ending in deposits of particles of iron rust. Such 

 water is more unpleasant than injurious, being especially unsuit- 

 able for laundry use. The iron may, and usually does, come from 

 iron salts in the rocks; but in some cases it is due to the use of old 

 chain-pumps. In the former case it cannot be remedied, but in the 

 latter can be, and ought to be. 



Having been provided by nature with the best of ground water, 

 what kind does the average farm household use for drinking and 

 other domestic purposes? An examination of many farms will show 

 that the well has been located with more regard for convenience than 

 health. A common situation is within fifty feet of a sink-drain, a 

 privy-vault, or a barn-yard, and sometimes the well is surrounded 

 by all three. Usually a curb or embankment prevents any surface- 

 wash from entering the well ; but it does not appear to be borne in 

 mind that a large part of the rain-fall soaks into the earth, carrying 

 with it the soluble constituents of animal and kitchen wastes with 

 which it came in contact on the surface, sooner or later to reach the 

 well. 



The waters from such wells have almost always been found to 

 leave much larger amounts of solid residue than those from un- 

 polluted springs, and contain a higher proportion of chlorine, be- 

 cause salt is abundant in all animal excretions and kitchen slops. 

 The waters are usually hard, since lime is also an important constit- 

 uent of animal wastes. High chlorine at a distance from the ocean, 

 may be considered a sure indication of sewage pollution. The four 

 forms of nitrogen compounds in these waters give a larger aggregate 

 than in pure spring waters, but the relative proportions of free am- 

 monia, albuminoid ammonia, nitrites and nitrates, vary widely. 



