FARM MANAGEMENT 39 



age from them would naturally flow. A pond or stream is seldom 

 suitable for a family supply because its drainage-basin is usually 

 beyond the control of any single farm. A tight cistern connected 

 with clean roofs furnishes a safe source of supply if the cistern is 

 kept clean. (N. H. C. B. 53.) 



Diseases in Water. The question may be asked, What is the 

 specific effect on the human system of these substances which occur 

 in drinking water? It is the opinion of physicians, that many cases 

 of general debility and of bowel troubles may be ascribed to water 

 polluted by sewage. The latter complaints are especially apt to occur 

 in individuals who are newly subjected to such water, after being 

 accustomed to good soft water. This fact makes especially emphatic 

 the necessity of pure water on farms that accommodate summer 

 visitors from the cities. 



The greatest danger in the use of sewage polluted water, is the 

 possible presence of the bacteria which cause typhoid fever. These 

 germs of disease cannot exist for any length of time in good spring 

 waters, because there is too little matter for them to feed on; but 

 polluted waters furnish the necessary conditions for their mainten- 

 ance in the products of decomposing organic matter, and they may 

 live in such water several weeks, ready to poison some person obliged 

 to drink it. Of course, all waters showing high proportions of chlo- 

 rine and ammonia do not contain disease germs. It is commonly 

 assumed that the soil acts as a filter on water and removes all dan- 

 gerous matter as the water passes through it, but repeated trials by 

 sanitary experts have shown that neither earth nor any other com- 

 mon filtering material will remove disease germs from water unless 

 there is a thorough destruction of the soluble organic matter, thus 

 depriving them of food. (N. H. C. B. 53.) 



Nearly all of the bacterial life exists in the upper strata of the 

 soil. Soil ten or twelve feet below the surface of the earth is per- 

 fectly sterile, unless it has within it a crevice or opening so that 

 surface sewage can run down. Therefore due care should be taken 

 in digging and constructing a well so that direct contamination will 

 be prevented. 



Well Construction. The well itself must be so constructed that 

 the impurities can not get into it from above or from the sides. Water 

 should be filtered through ten or twelve feet of fine soil. To pre- 

 vent the surface pollution a water-tight wall should be built in a well 

 down below the water level. This can be built of hard, burned brick 

 and cemented on the outside. Clay should be pounded around this. 



Where drilled wells are used the lining of the well should be 

 an iron tube driven into the bore and the outside should be flushed 

 with thin cement. The well should be properly covered and the 

 surrounding ground should be considerably higher than the gen- 

 eral level of the soil. No well should ever be located down the hill 

 from filth heaps. The walls should extend at least 3 feet above the 

 surface of the ground and a ground fill made so that it will slope 

 from the wall. The top of the fill should be covered with at least 

 twelve inches of clay or loam, upon which it is advisable to have some 



