It is probable that the constant inhalation of very small quantities indeed would be prejudicial to health. DAMP HOUSES There is a very general consensus of opinion that damp houses are unwholesome. Why are they unwholesome? It is very doubtful if the constant inhalation of watery vapour is prejudicial to health. I am not aware that sailors and millers, and boatmen who spend their lives on the water, are a short-lived class, or that they are liable to diseases which are special to them as a class. The probable cause of the unwholesomeness of a damp house is its liability to grow moulds and mildews and allied organisms. The growth of putrefactive and pathogenic organisms is checked by dryness and encouraged by dampness, and it is probable that it is in this direction that we are to look for the causes of the unwholesomeness of damp houses. A friend built a house some eighteen months since on an eminence in a park having a stiff clay soil. His architect advised him to have cellars under the house 'for the sake of dryness,' and such advice is very general. Let us look at the question a little more closely. Suppose you build a house having an area of 50 feet by 50 feet = 2,500 square feet. If you have no cellar this 2,500 square feet of your house rests upon the soil, and six inches of concrete will effectually stop back the moisture. Suppose you have a cellar beneath the house, say 8 feet high, then you have to excavate 2,500 feet by 8 = 20,000 cubic feet of earth; and in addition to the floor of your cellar you have four sides, each 50 feet by 8 = 400 square feet, or 1,600 extra square feet in all, in contact with the damp earth. With a cellar you have 4,100 square feet ready to imbibe moisture from the soil, and without it you have 2,500 feet only. A big cellarage used for pantries, larders, beer, wine, coals, &c., &c., which is not artificially warmed, makes a house very cold; and if the cellarage communicate directly with the ground floor, there is a constant draught of cold air from the vaults beneath to the living-rooms above. Supposing such a cellarage to have walls and floor impermeable to moisture, it is inevitable that whenever the wind shifts from a cold dry quarter to a warm muggy quarter (say from N.E. to S.W.), condensation will take place, and the walls of your 'dry cellar' will stream with moisture. A cold damp cellar, which comes only occasionally under the surveillance of the master and mistress, and in which all sorts of odds and ends are poked away to accumulate dust and mildew, is an undoubted disadvantage to a house.