Salts with Salts.
This compoſition can hardly ever conſtitute a genus, if it muſt be made in a dry and concrete form; for excepting gypſum, the other native ſalts readily diſſolve in water, and by evaporation are ſo mixed together as not readily to be diſcerned by the eye. Yet the foſſil alkaly mixed with common ſalt will perhaps find a place here. The contents of mineral waters may likewiſe be referred here, ſince every material difference in them depends upon the particles diſſolved.
Salts with Earths.
This mixture is hardly to be found but where bits of gypſum are concreted to matters of an earthy nature.
Salts with Inflammables.
May perhaps be found in volcanoes.