Griffin, (Dissertation, 1895), prepared what he thought was a solution of the meta toluene sulphonic acid from the amide, and made and studied several salts as well as the anilide and toluide. However he did not investigate his solution to find out what it contained, but went ahead on the assumption that he had a solution of this acid. It is on the basis of his lack of investigation that I am working. The derivatives of para toluene sulphonic acid have been made and studied by Newell, (Dissertation, 1895), and are being investigated further. He prepared para tolyl phenyl sulphone by the Friedal-Crafts reaction, para phenyl sulphone benzoic acid by oxidation of the sulphone with chromic acid, its salts, chloride, amide, and anilide, and para benzoyl diphenyl sulphone from the acid by the Friedal-Crafts reaction, and studied their reactions and properties. The analogous derivatives of ortho toluene sulphonic acid were made and studied by Canter, (Dissertation, 1900). He prepared ortho tolyl phenyl sulphone by the Friedal-Crafts reaction, ortho phenyl sulphone benzoic acid by oxidation of the sulphone by potassium permanganate, its chloride, amide, and anilide, and ortho benzoyl diphenyl sulphone from the acid by the Friedal-Crafts reaction. The analogous derivatives of the meta toluene sulphonic acid with one or two exceptions have not been made or studied, nor has the acid itself been prepared in a form which could be recognized. The following derivatives of meta toluene sulphonic acid have been made and studied; the amide by Müller, Pechmann, Pagel, Beckurts, F.H.S. Muller, Nevile and Winther, Chase Palmer, Klason, Valin, Noyes and Walker, Metcalf, and Griffin; meta sulphamine benzoic acid by Limpricht and Uslar, and Griffin; meta toluene sulphon anilide and toluide by Muller and Wiesinger, (Ber. d. chem. Ges, 12,1348), and by Griffin; the latter also made and studied several metallic salts. The literature on the ortho and para toluene sulphonic acids and their derivatives is voluminous, and covers a great many derivatives which have been thoroughly studied and whose structure has been determined. The literature on meta toluene sulphonic acid is very meagre, comparatively, and all that could be found is mentioned in this paper. This would seem to indicate that investigators have avoided this series, and apparently the reason is due to the difficulties encountered in isolating the free acid. THEORETICAL DISCUSSION