A series of substituted sulphonamides has been prepared for a study of their chemotherapeutic activity against a number of different bacterial species. By condensingp-acetylaminobenzenesulphonyl chloride with primary aromatic and aliphatic amines, N4-acetyl-N1–substituted sulphanilamides were obtained. Hydrolysis with acid or alkali removed the acetyl group and gave the desired N1-substituted sulphanilamides.The appendix contains details of the techniques used in testing these sulphonamides. Although a few of the compounds described in this paper exhibit considerablein vitroactivity, none of them possess,in vivo, chemotherapeutic properties equal to those of sulfapyridine or sulfathiazole.