| Barium sulphate3 | ounces. |
| Ammonia fluoride1 | ounce. |
Acid sulphuric, a sufficient quantity to decompose the ammonia fluoride and making the mixture of a semi-fluid consistency. It must be prepared in a leaden vessel. It can be used with a common pen, but must be kept in bottles coated inside with paraffine, beeswax, or gutta-percha, with rubber stoppers.
To Drill and Ornament Glass.
Any hard steel tool will cut glass with great facility when kept freely wet with camphor dissolved in turpentine. A drill-bow may be used, or even the hand alone. A hole bored may be readily enlarged by a round file. The ragged edges of glass vessels may also be thus easily smoothed by a flat file. Flat window glass can readily be sawed by a watch-spring saw by aid of this solution. In short, the most brittle glass can be wrought almost as easily as brass by the use of cutting-tools kept constantly moist with camphorized oil of turpentine.
Plating Without a Battery.
Silver-Plating Solution.
| Nitrate of silver (crystals) 1/4 | ounce. |
| Cyanuret potassa 1/2 | ounce. |
| Prepared Spanish whiting1 | ounce. |
| Pure rain water2 1/2 | ounces. |
Mix all together in a glass vessel, and it is ready for use. Thoroughly clean the article from all grease and dirt (see polishing preparations, page [12]), and apply with a soft rag or brush and polish with a chamois skin.