The Study of the Comparative Development of the Brain through the Cranium--Importance of Cranioscopy--First Step--Facial organs--Miller, Pestalozzi, Danton, Mirabeau--Caricatures--Upper and lower parts of face--Female faces--Mode of comparing organs--Mode of manipulation--Bony irregularities--Profile comparison of height and depth--Vacca Pechassee and Lewis--Old errors--Difficulties in estimation--Morbid conditions--Criminals--Napoleon--Negro murderer. [Illustration: HUGH MILLER.] [Illustration: PESTALOZZI.] [Illustration: DANTON.] [Illustration: MIRABEAU.] The reader now understands the conformation of the brain, and the general character of its different regions. It is important that he should as soon as possible begin the study of heads, and learn to judge correctly their development. When he can do this, he has an inexhaustible source of knowledge continually with him, and every new acquaintance becomes an interesting study in ascertaining the indications of his head and comparing them with his daily conduct and manners. The more thorough and careful the study, the greater the satisfaction and delight that it yields. The good cranioscopist continually grows in knowledge, and solves all the problems of character presented in society. But he who simply studies the elements of character or organic faculties, and does not become acquainted with the organs and their measurement, soon finds his knowledge too abstract and remote from his daily life; and, instead of increasing his stock of knowledge on this subject, he continually loses more and more of what he has gained. It was for this reason, mainly, that the medical profession gradually dropped the discoveries of Gall, which would never have ceased to interest them if they had learned to apply them to the study of men and animals. I hope that no reader will neglect this chapter, or fail to reduce its instructions to practice, for on that it depends whether he shall become a practical master of cerebral science, and be able to read every character with which he meets.