TO COLOUR AGATES.
Brown.—Soak the stone in a solution of silver in spirits of nitre, dry in the sun, then put in a damp place, and on again exposing it to solar light, the colour will appear. Repeat to deepen shade.
Light Brown.—A solution of gold.
Gray.—Add to the silver solution a quarter of its weight of lard and red tartar.
Deep Violet.—Add to the silver solution some plumose alum.
White.—The action of bismuth bleaches it so that it looks white; it will appear pale brown in the shades.
To draw Figures on the Stone.—Rough it, write with a quill, and the silver solution will dry it quickly.
CARD CASTLE.
With a pack of cards make houses in this manner. Place two on their narrow ends, fixing the tops level.
