Reference is made to a previous report (Air Service Information Circular, Vol. 4, No. 308) with the same title, dated September 192, which covered some of the materials of interest in connection with the effect of doped fuels on the materials in the fuel system. The purpose of this investigation was to give a more complete idea of the corrosive effect of various doped fuels on materials used or proposed for use in the fuel systems. Tests were run with and without the addition of a small amount of water to the fuels.