Add half ounce of isinglass, or fish glue, and a small piece of loaf sugar.

Let all dissolve, and spread over French letter paper, with a brush or piece of sponge.

If once spreading is not enough, perform the same operation a second time.
Black Stain for Apparatus .-- Dissolve gum shellac in alcohol, or procure shellac varnish at the druggists', stir in lampblack, and apply with a sponge or bit of rag.

This will adhere to metal, as well as wood, and is used for the inside of camera, tubes, etc.
Sealing Wax for Bottles .-- Melt together six parts rosin and one beeswax, and add a small quantity of lampblack; or, if red is preferable, add red lead.

Common white wax is best, as most chemicals act less upon it.
When bottles containing bromine are to be sealed, it is well to grease the stopper.