If the ignorant prejudice against a complete study of the hand were overcome, the police would be greatly assisted by studying the lines of the palm, and acquiring a knowledge of what these lines mean, especially as regards mentality and the inclination of the brain in one direction or another.
It is a well-known fact that, even if the skin be burned off the hands or removed by an acid, in a short time the lines will reappear exactly as they were before, and the same happens to the ridges or "spirals" in the skin of the inside tips of the fingers and thumb.
The scientific use of such a study could also be made invaluable in foreseeing tendencies towards insanity, etc.
Sir Thomas Browne, in his _Religio Medici_, after referring to Physiognomy, says: "Now there are besides these characters in our faces certain mystical figures in our hands, which I dare not call mere dashes, strokes _a la volee_ or at random, because delineated by a pencil that never works in vain, and hereof I take more particular notice because I carry that in mine own hand which I could never read nor discover in another." But prejudice is a hard thing to combat, and, in consequence, a study which could render untold aid to humanity has been neglected in modern times.

Yet it cannot be denied that this strange study was practised and followed by some of the greatest teachers and students of other civilisations.
Whether or no these ancient philosophers were more enlightened than we are has long been a question of dispute, but the one point and the most important one which has been admitted is, that in those days the greatest study of mankind was man.

It is, therefore, reasonable to suppose that their conclusions are more likely to be correct than those of an age like our own--famous chiefly for its implements of destruction, its warships, its dynamite, and its cannon.
This study of hands can be traced back to the very earliest, most enlightened forms of civilisation.

It has been practised by the greatest minds in all those civilisations, minds that have left their mental philosophies and their monuments for us to marvel at.

India, China, Persia, Egypt, Rome--all in their study of mankind have placed the greatest store in their study of the hand.
During my stay in India, I was permitted by some Brahmans (descendants of the Joshi Caste, famous from time immemorial for their knowledge in occult subjects) with whom it was my good fortune to become intimately acquainted, to examine and make extracts from an extraordinary book on this subject which they regarded as almost sacred, and which belonged to the great past of the now despised Hindustan.
As the wisdom of the Hindus spread far and wide across the earth, so the theories and ideas about this study spread and were practised in other countries.