Glyceryl, trinitrate, C3H5 (ONO2)3. A dangerously explosive ester prepared by the action of nitric and sulphuric acides on glycerol. It is employed, either in a 1 per cent alcoholic solution (BPC 1959) or in tablets, as a heart stimulant, and it closely resembles erythrityl tetranitrate or ethyl nitrite in its action.