46 MEDICAL JURISPRUDENCE Galton System.—This system, which is also known as dactylography, consists in taking the impressions of the bulbs of the fingers and thumbs with printer's ink on an unglazed white paper and then examining them with a magnifying lens. It is based on the principle that the individual peculiarities of the patterns formed by the arrangement and distribution of the papillary ridges on the finger tips are absolutely constant and persist throughout life, from infancy to old age, and that the patterns of no two hands resemble each other. It has been estimated that the chances of two persons having identical finger impressions is about one in sixty-four thousand millions. The following case46 well illustrates the fact that it is possible for any two persons to bear striking points of resemblance on the body, but it is never possible for them to have identical finger impressions: — In 1917, Professor Canella of Milan, while serving the Army in Macedonia, was reported missing and was never heard of again. In 1924, a man suffering from loss of memory was admitted into a Piedmont asylum and he remained there for two years. Afterwards the wife and the daughter of the professor unhesitatingly identified him as the professor, as he bore remarkable external resemblance. He was at once taken to Milan, where all the friends of the professor at once recognized him. By degrees he appeared to recover his memory* and then asserted that he was indeed the lost professor, and purported to recall many incidents which had happened in the latter's career. All seemed well, but suddenly there fell a bolt from the blue. A woman appeared on the scene and identified him as her husband, Bruneira, who had absconded three years ago after a career of crime. The family and acquaintances of Bruneira, one and all, likewise identified him. He was examined and found to possess certain marks on the body, which, however, curiously enough were alleged by both parties of relatives to be lifelong marks of Canella and Bruneira respectively. The Italian Police produced the finger prints of Bruneira which were alleged to be identical with those of the man whose identity was in dispute. The ridges on the fingers and hands are studded with microscopic pores, which are the mouths of the ducts of the sweat glands situated below the epidermis. These pores may be used for personal identification, as they are permanent and immutable during life and vary in size, shape, position, extent and number over a given length of the ridges in each individual. This method of identification by examining the pores is known a^oroscogy, and is of the greatest value when a small fragment of a finger impressionrior an impression of a part of a palm is available for comparison. Before taking the impressions the fingers should be thoroughly washed, and rubbed clean and dry, as the slightest perspiration will cause blotches and blur the print. It should be remembered that the finger prints of lepej^- should, on no account, be taken, while those of persons suffering from infec- tious or contagious diseases should not be taken until they have completely recovered. Fingers smeared with blood, grease, dirt or slight perspiration may leave their impressions on weapons, clothing, glass panes, utensils, furniture, etc., hence considerable care should be taken in handling such articles during the investigation of a crime, and any articles found to possess such prints should be preserved for further examination. Finger impressions are either rolled or plain. A rolled impression is obtained by first inking the bulb surface of the finger or thumb between the nail boundaries and then placing the inked finger or thumb on the paper so that the plane of the nail is at right angles to the plane of the paper. The finger or thumb is then pressed lightly on the paper and turned over so that the bulb surface which originally faced to the left, faces to the right and vice versa, the plane of the nail being again at right angles to the paper. A plain impression is obtained by lightly pressing the inked bulb surface of the finger or thumb upon the paper without any turning movement. In a plain impression the whole contour of the pattern does not appear, whereas in a rolled impression the whole pattern is delineated. It is, therefore, easier to deter- mine the type of pattern from a rolled impression, and its greater surface enables the expert to select a larger number of points for comparison. 46. Times, March 1, 1927; 28 Criminal Law Jour., 1927, p. 62.