""What Is Phrenology?"" is a book written by Nelson Sizer and published in 1892. Phrenology is the study of the shape and size of the human skull to determine a person's character and mental abilities. The book provides an overview of the history of phrenology, including its origins in the late 18th century and its popularity in the 19th century. Sizer explains the principles of phrenology and how it was used to analyze personality traits and predict...