138 The tobacco plant, _Nicotiana tobacum_, is a native of America, and the use of tobacco began with the American Indians. It was taken back to Europe by the early explorers, Sir Walter Raleigh being credited with introducing it to the nobility of England. 139 Most headaches are the result either of eye strain or of digestive disturbances, such as indigestion and constipation, and are to be relieved through the work of the oculist or through attention to the hygiene of the digestive system.