I have discovered an excellent preparation to cover a discarded picture: a portion of white lead, ground in skimmed milk to the consistency of jelly, will effectually cover the surface of a discarded picture and enable the painter to make a new picture upon the same canvas. I have prepared new canvas according to the same mixture, and with entire satisfaction. After the first coat of paint is laid with this mixture, which will dry in about an hour, the pumice stone should be used to grind off the lumps of thread that may injure the level surface. The next painting it would be well to mix a little vermilion with the paste, in order to see that you have covered the canvas regularly. I have used this mixture since the year 1840. The canvas imported is liable to crack., ,,