MODERN FINGERPRINTING

Although the science of fingerprinting began with the work of Francis Galton in the nineteenth century, detectives still had trouble locating the tell-tale marks. Then, in 1982, some researchers at the US Army Criminal Investigation Laboratory in Japan cracked a fish tank. When they patched it together with superglue (cyanoacrylate), they noticed the fingerprints on the glass standing out in proud relief. The fumes from the glue had condensed on oils in the prints, rendering them highly visible. Cyanoacrylate is now an important weapon in the forensic scientist’s armoury.

TEFLON

Teflon was invented in 1938 by a DuPont research chemist named Roy J plunkett. One day he was experimenting with a coolant called TRE (tetrafluoroethylene) to establish its suitability for refrigeration purposes.

For some reason, the pressurised cylinder of the gas filled earlier by Plunkett’s assistant failed to discharge properly when the valve was opened. Throwing all safety rules out of the window, the pair decided to cut it open to see what had happened.

Instead of a violent explosion, they found that the gas had solidified inside the cylinder to form a strangely slippery white powder. Indeed, tests revealed that it was the slipperiest substance in existence. It was also inert and had an extremely high melting point.

DuPont registered Teflon as a trademark in 1945 and started marketing products coated with the miracle lubricant the following year. Since then, Teflon has not only been used for millions of frying pans, but also in microchips, rocket shields and space suits. The product was immortalised as the nickname of the supposedly unprosecutable New York gangster John ‘Teflon’ Gotti (nothing would stick) and has even been applied to the creaking joints of the Statue of Liberty.

Date: 2015-04-20; view: 1047