DISCOVERY 



259 



in results than the one known by the name of dactylo- 

 scopy. Like the patterns on the fingers, the pores 

 between those patterns are unchangeable. Moreover, 

 in shape and in size they are extremely variable, and 

 when the trace of these sudoriferous glands has been 

 enlarged by microphotography, we are provided with 

 an infallible means of identification. The smallest 

 portion of a finger print may thus be utilised, for 

 there are from nine to eighteen of these glands per 

 millimetre. Between one person and another there 

 is also infinite variety in the distances between the 

 pores. " In brief," says Dr. Locard. " the pores, 

 because of their immutability, permanency, and 

 variety, constitute a sign of identity of the first order. 

 Poroscopy (as this science is called), the only method 

 of identification in the case of ver>' small fragments of 

 prints, is, in all cases of dactyloscopic analysis, an 

 important complementary proof. A jury, unimpressed 

 by thirty or forty homologous characteristic points, 

 will be struck by the concordance of shape, position, 

 and number of some hundreds of pores found to be 

 identical in two compared prints. Poroscopic research, 

 which is difficult and hard to carry out on the original 

 traces, even by the use of a lens enlarging five times, 

 is practised by means of large photographic enlarge- 

 ments. With an enlargement of sixteen the work is 

 already easy. For demonstration before a jury one 

 can usefully enlarge up to fortj'-five times. In prac- 

 tice, poroscopy has very often enabled fragments of 

 prints measuring but a few square millimetres to be 

 used, or half-effaced prints in which only a few points 

 were visible. Above all, it enables one in numerous cases 

 to be clearh' affirmative, and strengthens the evidence 

 due to dactyloscopy^ in a most efficacious manner." 



Dr. Locard cites a large number of cases in which 

 this fresh advance in criminology has been successful. 

 As a good example we may take the Boudet-Simonin 

 case, in which two men with these names were arrested 

 on a charge of burgling a flat in Lyons, on June lo, 

 1912, and stealing a quantity of jewellery and 400 

 francs. There were no witnesses of the robberv. and 

 nobody could furnish the slightest piece of information 

 regarding the burglars. But a rosewood cabinet, from 

 which the jewels and money had been taken, was 

 literally covered with finger prints. These were 

 revealed by the aid of carbonate of lead and photo- 

 graphed. Search was then made in the finger-print 

 ai chives of the Lyons Police Laboratory, with the 

 result that certain prints were found to be identical 

 with those of a man Boudet, who had been several 

 times convicted of theft. The man's record at the 

 Surete showed that he often worked in collaboration 

 with a man named Simonin. Both were arrested. 

 And it was then found that the finger prints which 

 were not Boudet 's were Simonin 's. Thirteen prints 



from the former's hand presented 78 characteristic 

 points ; 2 prints made by the latter, including that 

 of the palm of his left hand, showed 94 points of 

 comparison. In the case of the middle finger of 

 Boudet's left hand 901 pores were identified, while in 

 that of Simonin's palm more than 2,000 homologous 

 pores were pointed out to the jury. On this sole 

 piece of evidence the men were sentenced to five 

 years' hard labour, the jury refusing to grant them 

 the benefit of extenuating circumstances. " I am 

 convinced," comments Dr. Locard, " that the demon- 

 stration of the homology of the pores played, in the 

 minds of the jurymen, the principal role." 



Stockis, another well-known criminologist, proved 

 experimentally that the wearing of leather or india- 

 rubber gloves need not prevent the formation of 



finger prints, and in February 1912, in the S 



case. Dr. Locard put theory into practice by identifying 

 a gloved burglar without any other proof than his 

 finger prints. The print was naturally less clear than 

 that of a bare hand, but nevertheless a fairly large 

 number of guiding marks could be distinguished. 



GRAPHOMETRY 



Another new method of criminal investigation, 

 which has rightly been declared to be even more 

 mathematical and more scientific than poroscopy, is 

 also due to the science and ingenuity of the head of 

 the Lyons Police Laboratory. It goes by the name 

 of graphometry, and is applied to the recognition of 

 written forgeries. The alteration of a document by 

 means of scratching out, writing over the top, or by 

 tracing can easily be recognised by microscopic 

 examination. X-rays also have been employed to 

 reveal other instances of tampering with documents. 

 But when there is merely imitation of handwriting, 

 and this imitation is apparently perfect, identification 

 of the forgery becomes difficult. How to unmask the 

 forger in such a case as this was the problem which 

 Dr. Locard set out to solve, with complete success. 



Dr. Locard's method of revealing the identity of the 

 forger or writer of anonymous letters is based on the 

 fact that there are peculiarities in the handwriting of 

 everyone which cannot be reproduced bj' the forger, 

 who, whilst attempting to imitate perfectly, involun- 

 tarily introduces his own peculiarities into the script. 

 Graphometry, then, consists in decomposing a given 

 piece of writing into measurable elements, and after- 

 wards proceeding to make rigorous comparisons of 

 numbered values. The complete technique of the 

 method cannot possibly be given in a magazine article ; 

 but the main principles, illustrated by two or three 

 examples, can be indicated. 



These principles are based on four methods of 

 analysis which take into consideration the height of 



