Term traditionally used as a synonym to turpentine, but more precisely to identify with the first distillation of the essential oil of turpentine (balsam of pine trees). The common 'spirit' is instead a commercial product of low cost obtained by adding the same mix of natural terpenes with a variable quantity of petroleum; mixes predominately on the basis of petroleum with small percentages of other solvents to hide the odor and make it more similar to that of turpentine.