The management of streptococcic and staphylococcic infections of the skin presents an important problem in daily practice. Of all the pyogenic infections of the skin, impetigo contagiosa is the most common. For this reason and because impetigo is the most superficial type of pyoderma, it offers an excellent opportunity to test treatment by topical applications of bacteriostatic and bactericidal drugs. It is now established, by the excellent work of Dohi and Dohi,1 Lewandowsky,2 Tachau3 and, more recently, Epstein,4 that impetigo contagiosa can be of streptococcic, staphylococcic or mixed bacterial origin. The common treatment of pyogenic infections of the skin has been the use of ammoniated mercury, mercurial lotions, silver nitrate solution or dyes. Although the results with these remedies were generally good, the time which they required to cure ordinary impetigo was rather long, often ten to sixteen days. It was for this reason that we