Young's Demonstrative Translation of Scientific Secrets / Or, A Collection of Above 500 Useful Receipts on a Variety of Subjects

by Daniel Young

209. TO DYE SLATE COLOUR

Tea grounds, boiled in iron vessels, set with copperas, makes a good slate colour. To produce a light slate colour, boil white maple bark in clear water, with a little alum. The bark should be boiled in brass utensils. The goods should be boiled in it, and then hung where they will drain and dry.