FINGER PRINTS

Hokitika Guardian, 16 October 1933, Page 3

FINGER PRINTS

A NEW METHOD - LONDON, October 20. A new method of securing finger--prints has been discovered by Professor Brose and Mr Winson of University College,' Nottingham, who give the results of their experiments in Nature. They state that by the use of ultraviolet rays on a powder called anthracene or phosphorescent zinc sulphide the highly coloured background can he eliminated and the finger-p Ant characteristics clearly reproduced by photography. “If A person, left his fingerprints on an article of an ordinary colour it-was quite easy to photograph after the article had been dusted with powder,” said Professor Brose,' “but if finger-prints were left on a highly coloured article .it was found that when this was photographed the reproduction of finger-print characteristics was not at all clear, and could not be definitely used by the police.

Mr Winson was determined to find a method of .photograph-rig finger-prints on a ‘jazz’ coloured article. We found that if a fine powder of anthracene or zinc sulphide is sprinkled on the ridge of an imprint oh a highly coloured art'cle and then exposed to dark ultraviolet rays tne powder retains the ultra-violet light. It thus becomes phosphorescent, and when a photograph of the article is taken the phosphorescent light negatives the highlj coloured background, and the important finger-print ridge characteristics ape clearly reproduced. The phosphorescent powder has also boon found particularly useful by the police in the detection of forged notes. The phosphorescent fay shows up certain characteristics jin a genuine note which fail to appear on a forged one.”