+ E spectra derived from the non-decomposing anions of some sulphur compounds are independent of the pressure of the collision gas. The compounds chosen for study contain peaks produced from either ortho effects or skeletal rearrangement fragments in their conuenfionul positive ion spectra. The dissociative + E spectra are either devoid of skeletal rearrangement ions or alternatively contain such peaks in small abundance. In contrast, peaks derived from ortho reactions are present in high abundance.