Most attempts to measure the potentialities of a drug in wound infections, whether in terms of prophylaxis or of treatment, suffer from extreme degrees of variation in the lesions studied. The wound variations occur in respect to size, depth, anatomic location, inflicting agents, degrees of contamination, types and numbers of organisms present and the amount of contained foreign matter. Wounds also vary with the individual patient as to age, concomitant disease, nutrition, individual host resistance and healing capacity. Still another source of variation is the management of the wound, the time elapsed between injury and definitive treatment, the extent of debridement and of wound closure, the degree of tension in closed wounds, adequacy of immobilization, frequency of dressings and the duration of hospitalization. In established infection all of these variables are present plus the factors of bacterial invasion, bacterial toxins and bacterial symbiosis, which further complicate the picture. Hence it