So far, the electronic noses developed by firms such as Alpha Mos. of Toulouse, France. have worked best for quality-control purposes. These machines compare products' aroma- fingerprints with pre-programmed standards that are known to correspond with what people have said that they like. And the range of senses that can be substituted electronically has now been extended to include taste as well as smell. Recently, Alpha Mos has launched a second analyser an electronic'tongue' that can fingerprint the compounds dissolved in a sample of liquid. The machine is accurate enough to work out, for example, whether the vanilla extract in a sample originated India or in Malaysia.