Fowler, O. S. The Practical Phrenologist and Recorder and Delineator of the Character and Talents. Boston: O.S. Fowler, 1869.
In the 19th century, phrenologists such as Fowler studied the structure of the skull and surfaces of the head to determine an individual's mental qualities. Different parts of the skull were thought to indicate the relative strength of specific aspects of an individual's character and intelligence.
Although it is now discredited as a pseudoscience, phrenology did contribute indirectly to greater understanding of neurology, particularly the concept of cortical localization.