Abstract
The suppression of the toxic character of catalyst poisons, by converting these into derivatives in which the normally toxic element is present in a shielded and therefore non‐toxic electronic state, constitutes a method of eliminating toxicity from impure catalytic systems which avoids the necessity for the actual removal of the poisons. In addition to a description of work in this field, an account is given of the desulphurization of coal gas by destructive hydrogenation in the presence of catalysts containing metallic thiomolybdates.