The discovery of two new chemotherapeutic agents from microbial sources has recently been reported. Their clinical application in treatment of local and systemic infections has demonstrated their effective antibacterial action, which appears to be more potent than that of any known chemotherapeutic agent. The few published reports regarding their utilization in ophthalmology have been somewhat dramatic; however, it appears from the small number of cases reported that the therapeutic potentialities of these agents have not been fully recognized by ophthalmologists.
The observation made by Pasteur and Jouber1 in 1877 that the infective power of the anthrax bacillus was decreased when its growth was contaminated by certain saprophytic bacteria is apparently the first report of the phenomenon of antagonism between different microbial species. The therapeutic value of microbial antagonism was soon recognized, for by 190O several reports appeared in regard to the use of an extract from cultures of Pseudomonas