The first source of fallacy in the arguments referred to lies in the misinterpretation of the term "sewer gas," connecting it with sewers in particular instead of with sewage in general. Thus, I find it stated that typhoid is "more prevalent in the suburbs and surrounding country than in the cities subjected to the contamination of sewer gas;" that diphtheria and scarlatina occur most fatally "in the country, where sewer gas is wanting;" and that in Philadelphia the extension of the sewage system into the rural sections has diminished the sickness from fever. Now the facts on which most sanitarians lay great stress are, that unsewered rural districts are more exposed to danger from fermenting filth than cities, that the ineffable atrocities of leaching cesspools and privy-vaults (those perversions of barbarism to which the American rustic clings as to his most precious birthright) do infinitely more to poison air, and soil, and water than all the blunders of city engineers and plumbers combined; and that, granting the worst that can be said of some city sewers which shall be nameless, even a bad sewer is better than none at all--which is merely equivalent to saying that it is better to carry away as much of one's sewage as possible than to keep the whole of it on the premises to decompose under one's nose. And the peril from this fount and origin of evil is augmented a hundredfold where the mania for "modern improvements" has invaded rural households. Long before sewers are thought of--even before the importation of the agonizing pianoforte--the suburban housewife insists on having a bath-room, including that sum and substance of vileness, a pan water-closet on the bedchamber floor, and a kitchen sink and "stationary tubs" down stairs; and these fixtures, commonly constructed in the cheapest and nastiest manner, are connected with an unventilated cesspool, serving as so many inlets to insure the constant pollution of the house atmosphere with the gases of decomposition. Then, in an uncemented basement a "portable furnace" is arranged to transport to the upper rooms not only the cellar-air, but the freely indrawn "ground atmosphere," laden with noxious vapors from the soil-soakage of cesspools or privies. It is not saying too much to affirm that for every one channel of filth-poisoning in a paved and sewered city there are at least three in the average village settlement, and if the evidence of insanitary conditions be found in "not more than one house out of five," it is because, unfortunately, very few physicians in this country have cared to learn how to look for it--familiarity with the doses of drugs and the results of disease being regarded in most of our medical schools as vastly more important than _rerum cognoscere causas_.