Acts especially upon the pneumogastric nerve and the medulla oblongata, producing complete relaxation and paralysis of the involuntary muscular system. Through the vagi also the digestive system is powerfully affected. According to Bartholow , "the emetic effect of tobacco is doubtless the product of three factors : its cerebral action, its local irritation of the gastric mucous membrane, and its specific emetic property. The secretions of the intestinal mucous membrane are increased, and the muscular layer is thrown into tetanic contraction, whence the catharsis which follows its administration." Its chief characteristic is a deathly nausea, accompanied by pallor, vertigo, cold sweat, and intermittent pulse. Characteristic symptoms.