Solvent Solvent A solvent (from the Latin "solvō", "loosen, untie, solve") is a substance that dissolves a solute (a chemically distinct liquid, solid or gas), resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. The quantity of solute that can dissolve in a specific volume of solvent varies with temperature. Common uses for organic solvents are in dry cleaning (e.g. tetrachloroethylene), as paint thinners (e.g. toluene, turpentine), as nail polish removers and glue solvents (acetone, methyl acetate, ethyl acetate), in spot removers (e.g. hexane, petrol ether), in detergents
Science of smells Science of smells The odorology or science of smells is a technology used mainly in criminology for judicial identification. The technology is based on the analysis of smells by dogs notably to merge the criminals or to identify the smell of objects (explosives, drugs). Olfaction of dogs is used for a long time by the police (location of drug, of explosives, of weapon, body of missing persons, criminals' identification) or the services of rescue (bodies buried under avalanches). From 1910, a dog handler Friedo Schmidt describes in his book Verbrecherspur und Polizeihund («The criminal links and the police dog») how