Lies Detected by Breath.

Pelorus Guardian and Miners' Advocate., Volume 29, Issue 34, 4 May 1917, Page 2

Lies Detected by Breath.

When a man is telling & lie he breathes differently from when Ive is telling the truth. The difference was discovered by means of some testa made upon his students by Professor Benussi, of Graz. He prepared cards bearing letters, figures, and diagrams, and distributed these among his pupils. These were required to describe the cards correctly, except in certain cases when the cards were marked with a red star and the students receiving them were required to describe them, falsely. Each student was watched carefully ny his fellows, who, ignorant of the nature of the card, tried to judge from his manner whether he was telling the truth or not. ffhe watchers were unable to judge with any certainty. Under the direction of Professor Benussi, the time occupied in inspiration and expiration, was measured, and the measurement was taken again immediately after he finished. It was found that the utterance of a true statement always dimminished the quotent obtained by dividing the time of inspiration by the time of expiration. Dr. Anton Rose, commenting on these results, remarks that the discovery furnishes a certain criterion between truth and falsehood. For even a clever liar is likely to fail in an attempt to escape detection by breathing irregularly, Professor Benussi having discovered that men are unable voluntarily to change their respiration so as to effect the result.