Phrenology, that is the study of personality traits by reading the bumps on the head, is as discredited as a science as the work of Petrus Camper in a previous post. But just like Camper's work it produced some interesting drawings of the human head that transcend the uselessness of the pseudo-science. Here are a few of them from Felix Edward Guerin-Menevilles'
Dictionnaire Pittoresque Histoire Naturelle, Paris 1836-1839. The prints are hand colored.
Books about Phrenology:
The Illustrated Self-Instructor In Phrenology And Physiology: With One Hundred Engravings And A Chart Of The Character
Amazing Face Reading: An Illustrated Encyclopedia for Reading Faces
Head Masters: Phrenology, Secular Education, and Nineteenth-Century Social Thought
Books about drawing the head:
The Artist's Complete Guide to Drawing the Head
Drawing: The Head (HT197)
Drawing the Human Head (Practical Art Books)
Facial Geometry: Graphic Facial Analysis for Forensic Artists
Figures and Faces: 2 (A Studio book)