Marble erections against a backing of brickwork will in a year or so's time show a. brownish stain, and probably this will gradually spread. The stains are caused by the close proximity of the marble to the brickwork. The marble, being of a crystalline and somewhat absorptive nature, has attracted the damp from the brickwork, and so become discoloured. In nearly all walls, especially those recently built, constant evaporation is taking place, and the effect of this evaporation is to draw the damp from the middle of the wall towards the surface. Marble work, therefore, should never be fixed solidly to a wall, but an air space should be left between it and the brickwork, with an open joint here and there to allow for the condensation that invariably takes place. It may be objected that, by allowing an air space, solid fixing could not be obtained, but this objection may be overcome by the judicious use of brass or copper cramps. There is no permanent remedy for the stains unless the marblework is detached from the brickwork. The discoloured marble may, however, be bleached by treating it with a solution of soap lyes and whiting, but this bleaching will not be permanent. Mix the soap lyes and whiting to the consistency of a paste, and apply a good coating with an old brush.

Let this paste remain on the marble for a couple of days, then wash off with clean water - rainwater for preference -repeating the process two or three times until the stains have been removed. To make the lyes, obtain, say, 7 1b. of American potash from the dry-salters, and dissolve in a pailful of rainwater. The lye is of such a caustic nature that it is dangerous to lingers and nails. If, therefore, any of the liquid gets on the hands, they should be at once well washed in water containing a few drops of vinegar or acid to neutralise the alkali.