60 HEALTHY AND UNHEALTHY RESIDENCES. 



amount of labor may accomplish a great deal in the way of comfort 

 and also in preventing disease. 



Soil Soil is both an air-conductor and a water-carrier, and it 

 contains a great variety of solid matters. As regards air, carbonic 

 acid gas is found in all porous soils, arising chiefly from the oxy- 

 d&tion of organic matter. Gases of all kinds will find their way 

 through the soil. Houses act as suckers to the ground on whicii 

 they are built, because the air inside is warmer than the external 

 atmosphere, and so sewer-gas, coal-gas, and indeed any other gaseous 

 matter, may be drawn from the earth below into our habitations, 

 and take the place of pure air. Foul air from cess-pools has been 

 sucked into nouses from quite a distance. The late Dr. Parkes 

 attributed to emanations from the soil, attacks of cholera, dysentery, 

 paroxysmal fevers, typhoid, and various forms of remittent fever. 

 The catch-basin of every house, where there are sewers, should be 

 ventilated through the down spout from the house eaves. 



The amount of surface as well as of so-called ground water in 

 the soil is of importance. Nearly all land has a current of water 

 flowing under it, at a varying depth, and it may be stated broadly 

 that the greater the depth or this ground water, the more healthy 

 is the site. But as a matter of health, it is of greater consequence 

 to attend to the surface water. Surface water collects chiefly on 

 clay soils, or is stopped by a clay sub or under stratum, and rises, 

 causing a moist surface. Inquiries instituted in England by the 

 medical oflicer of the Privy Council, and conducted by Dr. Bu- 

 chanan, went to prove that the prevalence of pulmonary consump- 

 tion is in proportion to* the dampness of the soil. Who can say 

 after this result that consumption is not a disease which may be 

 prevented? 



The sum of the matter as to soils, then, is this: Unless in Cal- 

 ifornia, or some other equally dry climate, avoid "made ground" 

 always if possible, but if this cannot be done, take care that the 

 ground has been " made " at least two years, and the longer the bet- 

 ter. When it is not a question of made ground, endeavor to choosf 

 a site with as little tendency to retain surface water as possible, with 

 a deep run of ground water. These conditions, of course, indicate 

 an avoidance of all clay soils, which are invariably damp and un- 

 wholesome, and of alluvial soils also, which, though porous, are 

 mostly wet, and as a consequence more or less malarious. Gravel, 

 the looser limestone formations, chalk, and, in some cases, loose 

 sand with permeable sub-soil, are, in a sanitary sense, the best soils 

 for residence locations. If, as will frequently happen, clay cannot 

 be avoided, it is specially necessary to insist upon good trenching 

 round the house, an impervious drainage system with steep grades, 

 and foundations built up with cement or concrete. 



It must not be forgotten, however, that the best soils may be 

 speedily fouled by imperfect drainage. A loose brick, careless lay- 

 ing of pipe sewers, insufficient cementing, and, in fact, any sort of 



