The Preparation of the Earth of Vitriol.
Calcine Vitriol in an earthen Pot to a red colour; powder it, and pour water on it, which let stand four and twenty hours to settle, then pour off the water: This repeat so often, until it's sweetned, and all the sharpness is taken off.
These Emplasters are sufficient for all intentions; however, those that desire to make use of some other common Emplasters, they may buy them from the Drug∣gists,Page 112〈1 page duplicate〉Page 113〈1 page duplicate〉Page 114 that keep Journey-men-Apo∣thecaries for the same purpose, at as cheap a rate as they can prepare them themselves, which is far chea∣per than you buy them from the Apothecaries; who oft by keeping them too long in their Shops, or not preparing them exactly, sell Emplasters far worse, and of much less vertue, than those that are sold by the Druggists, who commonly take great care that their Medica∣ments shall be well and exactly pre∣pared.
THe Rates of Emplasters at the Druggists you may see at the end of the ensuing Table of Rates and Prices of Druggs.