Identification by finger-tips.

  • Galton, Sir Francis, 1822-1911.
Date:
1891
Catalogue details

Licence: Public Domain Mark

Credit: Identification by finger-tips. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    M. Alphonse Bertillon assui'es me that he does not use finger- prints in connection with his system of anthropometric identification which is now employed in the French criminal service. The often- repeated tale of its use in the prisons of China is baseless, so far as I can leai-n after repeated inquiries, or, if it is not entirely baseless, it certainly rests on a very limited foundation that I have not yet succeeded in discovering. The only person who has used the method on a large scale as a check against personation by natives, is Sir William J. Herschel, during the tenure of his magistracy in Bengal, which commenced between thirty and forty years ago. I am beyond measure indebted to the finger-prints collected by him there and subsequently, which have been minutely compared by myself with other finger-prints taken recently from the same persons. He has suppHed me with all the material I possess for inquiring into the question of persistence, except one couplet, which consists of a set of impressions taken by a friend of mine from his own fingers seventeen years ago in sealing-wax and accidentally preserved, and of a similar set taken a few months since. Without the help of Sir W. J. Herschel I could not have planted my first step. Moreover, the quasi pocket apparatus that I employ for taking finger-prints is the same in its essentials as one that he recently devised and I copied. The patterns (see Fig. II.) are formed by the convolutions of delicate ridges, each of which is seen to be studded with small holes, which are the open mouths of ducts issuing from perspiratory glands. As a rule the issues of aU ducts are surrounded by slight elevations of the skin, but those on the inner surface of the hands and feet have the peculiarity of not being contained in separate elevations like craters in isolated cones, but of occurring along ridges, like the craters which stud the crest of some long mountain-chain. The ridges are based in a curious way, which I must not stop to describe, upon the subcutaneous papiU^ in which the ultimate organs of touch are enclosed. The ridges seem to me to act in a somewhat analogous way to the whiskers of a dog or cat. A slight pressure at the end of a hair in the whisker causes a forcible pressure at the side of the sheath that holds it, which is easily felt. So the ridges engage themselves in the roughnesses of the surface that we explore by rubbing it with the fingers, as is our wont, and the result is to forcibly affect the organs of touch which He below and to cause a sort of thrill, which varies according to the degree of roughness and enables us to discriminate it. We learn very little indeed of the nature of a surface by merely pressing the finger upon it; the ridges do not then come into play in the way I have described. The reason why patterns exist in the bulbs of the fingers is to be found in the presence of the finger-nail. If it were not for the finger-nail, the ridges would run athwart the fingers up to its very tip, just as they do below. But the nail disturbs their parallelism. Vol. XXX—No. 174 X
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