Some say that ultrasound began as early as 1826 when an underwater bell was used to determine the speed of sound in the waters of Lake Geneva. Actually, the real breakthrough came when the piezo-electric effect in certain crystals was discovered in 1880. The picture shown on this slide is Dr. Dussik in 1940 employing one of the first ultrasound systems in medical diagnostics. He actually attempted to locate brain tumors. It was one of the earliest attempts of scanning a human organ.