Etching Upon Glass. Procure several thick pieces of clear crown glass, and immerse them in melted wax, so that each may receive a perfect coating. When quite cold, draw on them with a fine etching-needle any designs, such as landscapes, crests, initials, etc, taking care to remove every particle of wax from such parts of the designs as are intended to be corroded. When all the drawings are finished, the pieces of glass should be placed one by one (G) in a square leaden box (A), which has one side made of glass (C), carefully coated with hard etching varnish, or what is better, melted wax, or mastic varnish, and luted into the frame with bordering wax. The glass side allows the progress of the etching to be observed. The leaden box (A) should be made to drop into a leaden trough with a perforated false bottom (B), but in such a manner that the edge may be surrounded with water, and also the bottom covered with water to absorb the superabundant gas. To the bottom of the receiver or box should be carefully luted a leaden pipe (H), which is attached to the beak of a leaden retort (E) resting in the stand (F), with a spirit-lamp (D) under it. When sufficiently corroded, the glass plate may be removed, but it is necessary to have gloves on, and the hands covered with grease, to prevent the acid attacking the flesh. Those parts that are bit in enough, must be stopped out, as in common etchings (the plate being previously washed and dried), and the corrosive process combined until the several gradations of shade are obtained.