Finger-prints and foot-marks have again and again been cleverly worked into undeniable evidence. The impression of the first is personal and peculiar to the individual; by the latter the police have been able to fix beyond question the direction in which criminals have moved, their character and class, and the neighbourhood that owns them. The labours of the scientist have within the last few years produced new methods of identification, which are invaluable in the pursuit and detection of criminals. The patient investigations of a medical expert, M. Bertillon, of Paris (one of the witnesses in the Dreyfus case), developing the scientific discovery of his father, have proved beyond all question that certain measurements of the human frame are not only constant and unchangeable, but peculiar to each subject; the width of the head, the length of the face, of the middle finger, of the lower limbs from knee to foot, and so forth, provide such a number of combinations that no two persons, speaking broadly, possess them all exactly alike. This has established the system of anthropometry, of “man measurement,” which has now been adopted on the same lines by every civilised nation in the world. The system, however, is on the face of it a complicated one, and at New Scotland Yard it has now been abandoned in favour of the finger-prints method. Mr. Francis Galton, to whose researches this mode of identification is due, has proved that finger prints, exhibited in certain unalterable combinations, suffice to fix individual identity, and his system of notation, as now practised in England, will soon provide a general register of all known criminals in the country.
The ineffaceable odour of musk and other strong scents has more than once brought home robbery and murder to their perpetrators. A most interesting case is recorded by General Harvey,[1] where, in the plunder of a native banker and pawnbroker in India, an entire pod of musk, just as it had been excised from the deer, was carried off with a number of valuables. Musk is a costly commodity, for it is rare, and obtained generally from far-off Thibet. The police, in following up the dacoits, invaded their tanda, or encampment, and were at once conscious of an unmistakable and overpowering smell of musk,
which was presently dug up with a number of rupees, coins of an uncommon currency.
In another instance a scent merchant’s agent, returning from Calcutta, brought back with him a flask of spikenard. He travelled up country by boat part of the way, then landed to complete the journey, and carried with him the spikenard. He fell among thieves, a small gang of professional poisoners, who disposed of him, killing him and his companions and throwing them into the river. Long afterwards the criminals, who had appropriated all their goods, were detected by the tell-tale smell of the spikenard in their house, and the flask, nearly emptied, was discovered beneath a stack of fuel in a small room.
Yet again, the smell of opium led to the detection of a robbery in the Punjaub, where a train of bullock carts laden with the drug was plundered by dacoits. After a short struggle the bullock drivers bolted, the thieves seized the opium and buried it. But, returning through a village, they were intercepted as suspicious characters, and it was found that their clothes smelt strongly of opium. Then their footsteps were traced back to where they had committed the robbery, and thence to a spot in the dry bed of a river, in which the opium was found buried.