The classification employed by the English police was devised by Sir Edward Henry and is a modification of that of Sir Francis Galton, from which it differs in making use of four types instead of three. The impressions are grouped into arches, loops, whorls, and composites. The last group includes patterns made up of combinations of the other three, or those which might be classified either as loops or whorls. There are also numerous subdivisions of the group into patterns with characteristics in common such as "central pockets" and "accidentals," and further differentiation is effected by counting the number of ridges between two fixed points in the patterns. Examples of these four groups are shown in the plate facing p. 66. Dr. Faulds, who, while at a hospital in Japan, made an exhaustive study of the finger impressions of the Japanese, appears to have been the first to suggest the possibility of tracing a criminal by the imprints of his fingers upon external objects. He mentions two instances where the method had afforded valuable evidence, and these are worth recording as early examples of the use of the system in detective work. [Illustration: TYPES OF FINGER PRINTS] In one case some rectified spirit had been drunk, and the greasy marks of the fingers upon the bottle plainly showed who was the culprit, for their pattern was identical with that of an imprint in Dr. Fauld's collection. On another occasion someone had been suspected of breaking into a house, but the sooty imprints of fingers left upon the wall proved beyond all doubt that this was not the person. The finger-print system of identification was adopted by the police in this country in July, 1901, and the numbers of identifications made since then by the police at Scotland Yard are very remarkable. Up to the end of 1901 there were 93 identifications, which rose in the succeeding years to the following numbers: In 1902, 1,722; in 1903, 3,642; in 1904, 5,155; in 1905, 6,186; in 1906, 6,776; in 1907, 7,701; in 1908, 9,440; and in 1909, 9,960. There have been some very striking instances of the detection of criminals by means of their finger-prints, a few of which may be quoted by way of illustration. On March 20, 1908, a man named Chadwick was tried at the Birmingham Assizes on the charge of housebreaking and stealing at Edgbaston. He had left finger-prints upon a champagne bottle, and when these were made clear by the application of powdered blacklead they were found to correspond exactly with the finger-prints of the prisoner. Inspector Collins, in giving evidence on this point, stated that there were a million and a quarter classified finger-prints at Scotland Yard, and that these could all be distinguished from one another. He pointed out that there were twelve ridges which were characteristic and identical in the two prints.