This article was written in 1891 by Francis Galton, who, among his many major achievements, created a very thorough method to classify fingerprints. As the US Marshal’s office site notes, “Galton identified the characteristics by which fingerprints can be identified. These same characteristics (minutia) are basically still in use today, and are often referred to as Galton’s Details.”
The story below appeared before even the first of Galton’s three books on fingerprint science were published, and represents a very early perspective on the potential of using fingerprints to positively and uniquely identify people… which, of course, has long since become reality. Incidentally, this piece appeared in print six months before the death of Galton’s cousin — another man whose scientific theories rocked the world: A man named Charles Darwin.
Visible tokens of identity
Markings on human fingers do not change materially
What a finger or a finger print discloses when viewed under a powerful lens. The way to identify convicts.
by Francis Galton
Every one bears on his body a visible token of identity which has the unique value of persisting throughout his whole life. It apparently becomes fully defined some three months before his birth, and it remains unaltered after his death until the final stage of corruption.
This token of identity lies in the system of ramification of the minute ridges that run across the palm of the hands and soles of the feet, and it more especially resides in the scrolls or other patterns that the ridges form on the inner surfaces of the bulbs of the fingers. Attention will be directed almost exclusively to the latter, as they are amply sufficient in themselves for purposes of identification, while they are easy to print from and are conveniently isolated.
The utility of a sure means of identification cannot be doubted, if it admits of being easily applied to show either (1) that a man is the person he professes to be, or (2) that he is not the person whom be is suspected to be, or (3) that he is or is not included among the persons whose names and tokens are to be found in any given register. In criminal investigations, the existence of such a method would settle questions of personation, of mistaken identity, and of previous conviction.
In the army and navy, it would afford a sure means of convicting deserters and be a powerful deterrent from desertion. It would supply an invaluable adjunct to a severe passport system, it would be of continual good service in our tropical settlements, where the individual members of the swarms of dark and yellow-skinned races are mostly unable to sign their names and are otherwise hardly distinguishable by Europeans, and, whether they can write or not, are grossly addicted to personation and other varieties of fraudulent practice.
There remain other cases that occur rarely, but when they do occur are of sufficient importance to make it well worth the while of persons about to emigrate to take the small trouble of leaving their finger prints behind them as a token of their identity. For in a large population like ours, whose members migrate to all quarters of the earth, the instances are numerous of men who, having left their homes in youth, find a difficulty on their return after many years in proving claims to kinship and property.
Kinship and property
Or some alien scoundrel from foreign parts may assert himself to be the long-lost rightful claimant to an estate held in previous security by others on the supposition of his decease. Lastly, the important need often arises of performing the gruesome task of placing data on record that might afterward serve to identify the unknown victim of an accident, as of the stranger who dies in hospital of a wound that left him speechless, of bodies washed up after a wreck, or of the other ghastly content of a morgue.
Alphonse Bertillon assures me that he does not use fingerprints 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 learn 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.
The patterns, as shown in cuts, 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 all 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 on subcutaneous papillae, in which the ultimate organs of touch are enclosed.
The ridges seem to me to act in a some what analogous way to the whiskers of a dog or cat. 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 surfaces 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 lie below and to cause a sort of thrill, which varies according to the degrees of roughness and enables us to discriminate it. We learn very little of the nature of a surface by merely pressing the finger upon it; the ridges do not then come into play in the way described.
When a finger or a fingerprint is scrutinized under a lens, even of low power, it is seen to abound in minute peculiarities, due to the branching of existing ridges and to the abrupt interpolations of new ones. It is in these minutiae, as well as in the general character of its outline, in which the extraordinary persistence resides on which I am about to speak. The pattern grows together with the finger, and its proportions vary with fatness or leanness, and are further deformed by usage, gout and age, which makes the hands of old people less sightly than those of young ones. But, though the pattern, as a whole, may become considerably altered in length and breadth, the number of ridges that concur in forming it and their embranchments and other minutiae remain unchanged.
It is easy to take good prints with a little box three and a half inches square by seven and a half long, containing a slip of stout glass, a small and good printer’s roller, a collapsible tube filled with very fluid printer’s ink, a book of blank paper, and a phial of benzole and some rags to clean the fingers. A drop of ink is squeezed out of the tube on the glass, and is spread very evenly and very thinly over it by the roller. Then the fingers are lightly pressed, first on the inked surface of the glass and afterward on smooth paper. Finally, they are cleaned.
The photographers as a class would be well-qualified to take fingerprints neatly, which they would know how to mount artistically. They would also probably photograph the result. It is easy for them to try the process of finger printing. A piece of half-inch India rubber tubing stretched over a wooden cylinder is a makeshift for a printer’s roller that is not to be despised, and boiled or burnt linseed oil procurable at the oilman’s, and mixed with a little fine soot that has collected on a plate held over a candle, makes a serviceable ink.
For the future
I look forward to a time when every convict shall have prints taken of his fingers by the prison photographer at the beginning and end of his imprisonment, and a register made of them; when recruits for either service shall go through an analogous process; when the index member of the hands shall usually be inserted in advertisements for persons who are lost or who cannot be identified, and when every youth who is about to leave his home for a long residence abroad shall obtain prints of his fingers at the same time that the portrait is photographed, for his friends to retain as a memento.