Acts upon the cerebro-spinal and the sympathetic nervous systems, producing brief excitation, rapidly followed by depression and paralysis of all functional activity. As a result there is a general torpidity of the entire system. The cerebral powers are overcome, and stupor ensues ; motion and sensation are destroyed ; the secretions of the mucous membranes are diminished, and the mucous surfaces become dry and congested ; the breathing becomes slow, sighing, and irregular ; the heart's action is retarded, and these evidences of cerebro-spinal paralysis continuing, death results ; or, passing off, leave deranged digestion, headache, sleeplessness, and constipation. The leading feature of Opium is its depression of the cerebral functions, indicated by great drowsiness and stupor, with stertorous breathing. Characteristic symptoms.