There is a wide range of choice in the many washable distempers now on the market; but whether any of them would cover defects so as to prevent their re-appearance depends entirely upon what causes the stains. If they are lichenous growths, an application of dilute sulphuric acid will have a beneficial effect in the matter of destroying the vegetation, but a deleterious effect upon the stucco, the surface of which will be more or less disintegrated, according to the strength of the acid. Try the effect of a good brushing with a stiff bass dandy; then, for a cheap wash, and one that will look better than a white preparation, add Portland cement to water in which white copperas has been dissolved at the rate of l lb. to 3 gal. Apply the mixture, with frequent stirring, in the same manner as distemper. A second coat may, if considered necessary, follow as soon as the first is dry.