Page:Theophrastus - History of Stones - Hill (1774).djvu/307

 diolving Part of its purer Chalk as it goes.

7. Water thus aturated with the Principles of Sulphur, and with Chalk, keeps on its gradual Coure horizontally thro' the ame Lime Rock, till it meets a Fiure; a perpendicular Crack, or Opening; dividing one Part of the Rock from another. Here it ouzes forth: and meeting with a lighter Air, hangs; and evaporates lowly.

8. Slow Evaporation, and perfect Ret, are the Requiites of Crytalization. The Sulphur and pure Chalk thus united, form one olid Body; which crytalizing gradually, appears in regular rhomboidal Particles: and is the Subtance we call Spar.