In Vacca Pechassee the height is to the depth as 11 to 9; in Lewis as 9 to 11. In J. R. Smith the height is to the depth as 12 to 10; in the slave trading count as 9 to 14. This is the correct method of cranial study, for comparing the moral and animal nature.
The basilar depth was entirely overlooked in the old method of phrenologists, and hence they were very often mistaken in judging the basilar energy by breadth alone, of which there has been no more striking example than that of the Thugs of India, whose heads (though a tribe of murderers) were below the European average in basilar breadth. These facts are so conspicuous to any careful observer that I became very familiar with them in the first six months of my study of heads fifty-two years ago.
When the circulation of the brain is vigorous and regular, all portions being in regular activity, the fulness of the circulation being shown in the face, we may be sure that the character is fairly indicated by the cranium. The younger the individual the thinner the cranium, and the less the liability to deception by the thickness of the bones. Female skulls are _generally_ more delicate than male, and also more normal or uniform in their circulation. Hence there is less difficulty in making an accurate estimate of women and of youth. The greater difficulty is found in men of thick skulls and abnormal brains, and these difficulties are in some cases insurmountable by mere measurement. It will become necessary in the depraved classes to look at the condition of the circulation about the head, and the facial indications of the organs that have been cultivated. If these are not sufficient to guide us we must fall back upon psychometry.
The morbid condition of the brain is a conspicuous fact, which we must not ignore, and it is important to learn how to detect it in the appearance of the individual, or in his psychometric indications and Pathognomy, which is itself a profound science and important guide to character. (Pathognomy is the science of expression, and has an exact mathematical basis.)
We should bear in mind that it is just as possible to have impaired and unhealthy conditions in any part of the brain as to have them in the stomach, liver, lungs, or spinal cord. Physical diseases are contagious and so are moral. It is generally impossible to preserve the moral organs and faculties of a youth in healthy condition who is allowed to associate habitually with the depraved; and it is very difficult indeed for the mature adult to preserve his brain and mind in sound condition when compelled to associate with the depraved. To those who are very impressible, the contagion of vice, bad temper, profanity, turbulence, lying, obscenity, sullenness, melancholy, etc., is as inevitable as the contagion of small pox.