Acts powerfully upon mucous surfaces, causing an enormous flow of watery serum from the first mucous membrane that absorbs it, whether it be in the nose, oesophagus, stomach, or intestines. Its most important action is upon the gastro-intestinal canal, where its characteristic effects are produced, causing vomiting of the excessive gastric secretions and violent purging, stripping the intestinal membrane of its epithelium, a gastro-enteritis resulting from its prolonged action. Characteristic symptoms.