Take 24 oz. of alum, and 4 oz. of white soap, and dissolve them in 2 lbs. of water ; into another vessel dissolve 2 oz. of gum ara-bic, and t oz. of glue in the same quantity of water as the former, and add the two solutions together, which is now to be kept warm, and the paper intended to be made water-proof dipped into it, passed between rollers, and dried ; or without tlie use of rollers, the paper may be suspended until it is perfectly dripped, and then dried. The alum, soap, glue and gum form a kind of artificial Leather, which protects the surface of the paper from the action of water, and also renders it somewhat fire-proof. This is a preparation for water-proofing paper intended for packages exposed to the weather, recommended by Professor Muschamp, of Wurtem-burg, Germany.
This article was originally published with the title "Paper Impervious to Water"