108. The inside of the house not only becomes dirty by the dust carried in by the air and the dirt brought in by the feet, but from the odour or smell given out by our skin, and by the lungs with the breath.
This smell or odour is absorbed by all porous substances, as the walls, floors, and ceilings; it then decays, and gives rise to that close, sickening, un-wholesome smell, which is present in all dirty houses, especially such as are overcrowded. No house with such a smell can possibly be a healthy place to live in. This animal effluvium, or smell of decay-ing animal matter, is taken up by some substances much more readily than others. Walls that are covered with paper smell much more offensively than those that are painted. And in rooms where one paper has been pasted over another the whole thick-nesses of paper become very offensive and injurious to health. Painted or lime-washed walls are much to be preferred to papered walls for crowded dwellings and for all sleeping rooms.
Woollen garments, carpets, and curtains absorb these smells freely, and give them out for a long time. Rough wooden floors also take them up, and consequently require frequent washing; smoo thed waxed, or painted floors are much preferable to rough wooden ones.