406 APPLIED PHYSIOLOGY 



and sorted, and a large share of the cost of its removal is 

 met by the sale of useful material which is recovered. In 

 thinly settled places all household waste is often thrown 

 on an ash heap behind the most convenient outbuilding, 

 producing an offensive accumulation which might become 

 dangerous if material from a case of infectious disease 

 were mixed with it A garbage pile usually becomes 

 offensive and a menace to health from one or more of 

 three causes. 



First, water in any form keeps the mass wet and in a 

 decaying state. Liquid slops and waste containing offen- 

 sive matter should never be poured upon it. Dry garbage 

 is seldom unhealthf ul. That which cannot be utilized or de- 

 stroyed should be kept dry and its combustible parts burned. 



Second, bones and other table scraps and kitchen refuse 

 decay and furnish a soil in which bacteria of disease may 

 survive and possibly grow. Most of these substances 

 might be used as food for poultry or as garden fertilizer. 



Third, dirty tin cans containing rain water are offensive 

 and become breeding places for flies and mosquitoes. 

 Cans which are clean and dry are useful and salable. 



709. Sewage disposal. Ordinary household sewage is 

 over ninety-nine and one half per cent water, and is in a 

 state of offensive putrefaction. Its proper disposal is 

 necessary, for it often contains disease germs. In an ordi- 

 nary family which has no bath room or running water, 

 each person uses only a pail or two of water daily. The 

 resulting sewage is almost entirely kitchen waste and wash 

 water, and may safely be thrown upon the ground if the soil 

 soaks it up at once. If there is a bath room and running 

 water, each person is likely to use at least twenty gallons 

 of water daily. . The drain pipes should lead the waste 

 water either into a cesspool or into a sewer (pp. 137, 253). 





