Taking Their Dust

“Since I ran down that coiner by the zinc and copper filings in the seam of his cuff …”

– The Adventures of Shoscombe Old Place (SHOS)

From the Topics Of The Times column from the December 19, 1930 issue of The New York Times.

Taking Their Dust

Master minds in detective fiction have long been able to perform amazing feats of deduction. By careful scrutiny of a footprint, a hair, a bit of ash, they are able to describe in detail the unknown murderer. But they have the author on their side. In real life the detective fights against greater odds. But he has the modern scientist with him.

The director of the police laboratory at Lyons has developed a method of dust-detection to vie with any Sherlock Holmes or Arsene Lupin sleuthing. A notable instance of its use occurred in the arrest of a group of men with false coins in their possession. They were suspected, of counterfeiting as well as passing the coins. But there was no evidence of the former. Pursuing the scientific director’s method, their clothes were carefully brushed and a chemical examination was made of the dust. It was found to contain pyro-antimoniate of sodium, tin salts and a great amount of lead — proof positive of their criminal occupation.

The Lyons official has made a long study of what he calls “professional dusts.” He has shown that tell-tale evidence of a person’s work may remain in his ears, nostrils and clothing for as long as two years after he has given it up. A man’s occupation is as surely marked by this invisible dust as by a rolling gait or a calloused finger.

Originally published in the Topics Of The Times column from the December 19, 1930 issue of The New York Times.