IOWA ACADEMY OF SCIENCES. 241 



which often culminate in prolonged illness, or even death; 

 not only is waste of all kinds a menace to the public 

 health, but it is also a repulsive sight to the aesthetic 

 tastes of any civilized community. This last factor alone 

 would make sewage disposal a question of considerable 

 importance, as the value of property depends to a consid- 

 erable extent upon its attractiveness, and anything which 

 takes away from its good appearance deducts from its 

 market value. 



The question of sewage disposal is coming to be recog- 

 nized by the officers of the state boards of health in the 

 various states. Perhaps, as leaders in this movement, may 

 be mentioned Massachusetts, Connecticut and Maryland. 

 The State Board of Health of Iowa (14), in its annual 

 report for 1899, called especial attention to the almost utter 

 lack of adequate means of sewage disposal in the small 

 towns and cities of the state, and urges that some action 

 be taken toward securing proper sewage disposal. 



In considering the question of sewage disposal it may be 

 w^ell to define what is meant by sewage. Sewage, accord- 

 ing to Barwise (3), comes from the Anglo-Saxon word 

 seon, which means to flow down and includes the liquid 

 contents of a sewer. Rafter and Baker (5), however, give 

 sewage as including not only the combined water and 

 waste matters flowing in sewers, but the mixed solids and 

 liquid matter. This latter, it seems, is a better definition 

 as it includes the solid excreta as well as the matter in 

 solution. 



The kinds of sewage will necessarily vary with the im- 

 posed conditions. The most common may well be termed 

 domestic sewage, which contains kitchen slops and all the 

 common refuse of ordinary dwellings. Factory sewage is 

 more complex in most cases, depending, of course, upon 

 the particular kind of factory under consideration. Pack- 

 ing house sewage would hardly come in this category, yet 

 it plays a very important part in sewage disposal on ac- 

 count of its peculiar constituents. Surface sewage, if such 

 it may be called, is composed chiefly of water, and the 

 washings from the streets, alleys, etc. City sewage being 



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