The Scientific Detection of Crime. the law authorities was, whether black hair could be dyed fair. One of the first hair dressers of Paris, who was consulted, de clared that it was impossible; but Orfila stated that it was not only possible, but that it had been done twenty-six years before by Vauquelin, by means of chlorine. Since that time it is commonly done, and, in the greater number of instances, the hair of the criminal is red, sandy, or brown, and it is dyed black by preparations of silver, lead, bismuth, or sulphur, first wash ing the hair with some alkali. To bleach it, chlorine water or peroxide of hydrogen is chosen. In spite of these ingenious meas ures, however, the chemical expert is ahead of them; for at his disposal he has reagents to detect the metal, which is readily found, or by close inspection he can, at the end of a day or two, see the difference in color between the dyed portion and the natural hair. In speaking of the obliteration of certain scars and India-ink marks, it is stated, in opposition to the popular idea, that these stainings are not indelible. Cas par and Hutin have devoted themselves to the investigation of the subject, and found in many cases that scars could be removed. In regard to India-ink and other pigments which have been pricked into the skin, we have an admirable article by Tardieu in the"Annales d'Hygiene Publique," vol. iii. p. 171. One prisoner seen by him removed the India-ink tattooing very rapidly by a paste containing acetic acid and other sub stances. In a few days a crumb dropped from the skin, leaving a clean surface. Questions of identity based upon striking peculiarities of the individual are often cleared up by the merest chance; for ex ample, a man was found murdered, and from the direction of the knife-wound it was strongly suggested that the murderer was left-handed. After vain attempts to solve the difficulty, he was told to hold up his right hand; thrown off his guard, he immediately held up his left. The slightest trifles will be seized upon 38
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by the watchful detective, and often secure conviction. No better example can be given than that cited by Best. The criminal was detected by a certain malformation of his teeth. A robbery had been committed, and in the morning some partially eaten fruit was found upon the table in one of the rooms. The attention of the police was called to peculiar teeth-marks upon the apples, indicating the absence of two front teeth from those of the eater. An indi vidual with this dental defect had been seen lurking about the vicinity a few days before. When taxed with the crime, he promptly confessed it. So, too, are the footprints tell-tale witnesses in many cases, though this proof is not so valuable as it might be. A slipper or boot may often make a print which is really much larger than the foot, and which it does not subsequently fit. M. Hougolin has devoted himself to this branch of the study, and devised a plan which enables him to take impressions of feet in the soil for comparison with those of the suspected criminals. He raises the temperature of the impressed ground to 2120 by placing over it a brazier of live charcoal. He then dusts pulverized stearine into the impressions, which, when cold, is removed, and he is enabled to preserve an exact mould of the footprint. A plastercast can afterward be made. Chemistry comes to our aid in many ways in the detection of crime. On several occa sions bodies have been so burnt or charred as to defy identification, and analysis is the only thing to fix the identity. A set of false teeth or even a button has escaped destruction, and has been secured to convict the criminal. In one instance the process of combustion had been so thorough that nothing was found except a small vitreous substance which, when examined by chemi cal experts, proved to be the mineral part of a set of false teeth. A mysterious mur der was committed in a small French town a few years ago. The victim was the cur/, and he was found dead with a ball through
