action of the lime, and, at the same time, prevent disruption of the coating and failure of the color used in the paint. =Outline of Tests.= The tests referred to as carried out by the writer were made on a brick wall forty feet long, surface-coated with a four-inch coating of Portland cement mortar made of one part of Portland cement and three parts of sharp, clean sand. After the cement had hardened for three days, the solutions under test were applied. In many of the tests outlined above, one-coat, as well as two-coat work, was used on different sections of the test surfaces. It was shown that the two-coat work gave far better results than with the one-coat work, and the writer would recommend for the painting of concrete at least two-coat work. Whenever paints containing Prussian blue or chrome green are applied to concrete surfaces, immediate whitening in the case of the blue, and yellowing in the case of the green, will take place, if any degree of action has been exerted by the lime within the concrete. For this reason, green is an especially delicate color to test and should be utilized for this purpose. The materials used, and the results shown at an inspection made after two years' exposure, are given herewith. =Test No. 1.= Concrete primed with a 25% solution of zinc sulphate crystals dissolved in water. A wide brush was used for the application, and the spreading rate was approximately 200 square feet per gallon. Second and third coated on the second day with No. 119 blue paint of the following composition: NO. 119 BLUE PAINT Sublimed white lead 50% Zinc oxide 35% Silica and barytes 12% Prussian blue 3% Ground in linseed oil, turpentine and drier. This panel, after three years' exposure, is in good condition. Slight checking observed. =Test No. 2.= Concrete primed with a 20% solution of (alum) (aluminum sulphate). Second and third coated with No. 119 blue. In similar condition to Test No. 1. =Test No. 3.= Concrete primed with zinc sulphate followed by two coats of para red. PARA RED FORMULA Blanc fixe 60% Whiting 25% Zinc oxide 3% Paranitraniline lake 12% Ground in linseed oil, turpentine and drier. Panel in fair condition with exception of slight crazing. Characteristic dullness of color after exposure shown. Bright red color restored upon washing. =Test No. 4.= Concrete primed with an 8% solution of stearic acid and rosin dissolved in benzine. Second and third coated with No. 119 blue. This panel is not in as good condition as Tests Nos. 1 and 2, and would indicate the inferiority of the priming liquid used. Color failing in spots and checking observed. =Test No. 5.= Concrete primed with mixture used in Test No. 4, and then given two coats of para red. Test is in about the same condition as No. 4.