Take 1 lb. of gum mastic, carefully picked; powder it and set it in an earthen vessel with 2 lb . of spirit of turpentine. Set this in a sand heat, or any other heat that is less than will make the spirit boil: let it remain (shaking it well continually) till the gum is dissolved. Take it from the fire and let it stand till the contents are cold. The varnish is then to be poured out, and separated from any little foulness it may contain. The best way is to make a quantity of this varnish at a time, and keep it in bottles closely stopped, exposed as much as possible to the heat of the sun. This will make it clear, and improve the colours in proportion to the length of time it is kept. Take 1 lb. of this varnish and half a pint of the drying oil; shake them well together; put them, in a bottle, to simmer on the fire for a quarter of an hour, when the mixture will be complete. But if it should curdle as it cooks, it must be set on the fire again, and simmered until, when cooling, it does not curdle, but appears like a white jelly.,