Grind 96 lbs. of English ochre with boiled oil, and add to it 16 lbs. of black paint; dissolve 1 lb. of yellow soap in one pail of water, on the fire, and mix it while hot with the paint. Lay this composition, without wetting it, upon the canvass, as stiff as can conveniently be done with the brush, so as to form a smooth surface; the next day, or the day after, (if the latter, so much the better,) lay on a second coat of ochre and black, with a very little, if any, soap; allow this coat a day to dry, and then finish the canvass with black paint. 526. PHOTOCROMATIC OIL PAINTING INSTRUCTION: Chemicals used in executing them:--chemical varnish, No. 1, 2 oz. damar varnish, 1 oz. spirits turpentine; (mix well together.) Finishing varnish, No. 2, 1 oz. spirits turpentine, 1 oz. alcohol, 1 oz. salt, 1 quart water. A camel's hair brush is needed for varnishing. Take a smooth pane of common window-glass, any size you choose, clean it well, then varnish one side of it with chemical varnish No. 1, lay it away where it will be perfectly free from dust, and let it dry twenty-four hours; next varnish the same side of the glass again, and let it dry about one half hour, or until the varnish becomes stickey. Immediately after varnishing the glass the second time, take the print that you wish to get an impression of, and immerse it in the solution No. 3; put the solution in a flat pan, and lay the print in with the face side up; let the print lay in the solution about five minutes, or until the paper is completely saturated, then remove it, taking care not to stretch it, and lay it on paper with the face side up, in order that the solution may dry from the face of the print. In this way prepare the print, getting it ready by the time the glass has dried one half hour. Next, carefully lay the face of the print on the varnished side of the glass, being particular to lay it on smooth and press it firmly to the glass, so as to exclude every particle of air; should there be any air left under the paper, it will show itself in spots, and must be pressed out. You now lay it away and let it dry another twenty-four hours; then, wet the back part of the print with water and with your hand or a wet cloth, rub the paper from the back of the print until it is so thin that the outlines of the picture can be seen from the back and of uniform thickness. You next spread a thin coat of finishing varnish (No. 2) on it and lay it away to dry. This will render it perfectly clear and transparent.--After this coat of varnish has dried, rub it over with a bit of fine sand paper, to make it smooth, and finish with two or three coats of No. 2 varnish. When dry, put it in a frame with the varnished side out, placing a sheet of light coloured paper on the back, this will give it the appearance of an oil painting. By following these directions you cannot fail to produce a beautiful picture. 527. FOR THE COMPLEXION