“…For example, the cases recorded by Baber and Stuart (1946) and by Mackay-Dick and Watts (1949) were apparently improved by penicillin, and the course of the disease in our third case may have been modified by the drug. On the other hand, the fatal case described by Weetch et al (1949) showed no response; though it should be noted that this patient died of uraemia, and that the leptospiral nephritis was superimposed on previously damaged kidneys, so that the effect of penicillin cannot be fully estimated. In Case 6 of our series, however, penicillin, begun on the fouirth day and continued for 14 days, did not prevent a recrudescence of fever during treatment.…”