The dissolution of the corrosion products of metals in deionized water at 38°C (100°F) is discussed. Copper, tungsten, cadmium, and Mallory-1000 give soluble corrosion products. Mention is made of 304 stainless steel, 1100 aluminum, titanium, tantalum, silver, and boron steel, all of which showed no soluble corrosion products. The significance of soluble corrosion products in reactor cooling water is discussed. Data were. obtained by chemical analyses of the water rather than from physical measurement of the test specimen.