1. The soaps of the α-brom fatty acids are usually more germicidal than the unsubstituted soaps. Only when B. typhosus was the test organism was there no increase in germicidal action.
2. For any test organism, germicidal action of the brominated soaps increases rapidly with increasing molecular weight up to a certain point, then diminishes. This is likewise true of the hemolytic titer. The point of maximal germicidal action varies with the different species of tests organisms. In the series studied, brominated soaps of 12 and 14 carbon atoms were most germicidal for the Gram-negative organisms, while soaps of 16 and 18 carbon atoms were most germicidal for Gram-positive organisms.
3. The brominated soaps are, in general, more active in acid that in neutral or alkaline reactions. The reasons for this have been discussed in a previous paper, in which a similar phenomenon with unsubstituted soaps was observed.
4. For certain organisms, the brominated soaps are among the most rapid and potent germicides known.