The alpha and beta phases of the copper-zinc system are easily identified by their distinctive colors. A method has been described whereby gamma and epsilon may be identified by anodic etching in 17% CrO3. At current densities over 1.5 amp. psi, gamma is attacked, epsilon not attacked. At low current densities the reverse is true. Eta is attacked under both conditions. Positive identification of the five important phases is thus secured. The flexibility of electrolytic etching as a method and its possible wide application are stressed.