Silvering
The Encyclopedia of Founding (1892)
Important: Safety Warning
This page contains a formula or preparation using substances now known to be dangerously toxic, such as arsenic, mercury, lead, or cyanide compounds. Exposure to these substances can cause severe poisoning, permanent injury, or death.
In addition, this page describes trade processes that use dangerously toxic materials such as cyanide solutions, mercury amalgams, or strong acids. These processes require training, equipment, and precautions far beyond what the text describes.
This information has been left in for historical purposes but should not be acted upon.
A silver-plating solution is made and applied as follows: put together in a glass vessel 1 oz. nitrate of silver, 2 oz. cyanuret potassa, 4 oz. prepared Spanish whiting, and 10 oz. pure rain-water. Cleanse the article to be plated by washing over with dilute nitric acid or potash-lye and prepared chalk, and apply with a soft brush. Finish with the chamois-skin or burnisher. Silvering with the Plating Powder.--Dissolve silver in nitric acid by the aid of heat; place some pieces of polished copper in the solution to precipitate the silver; wash the acid out in the usual way; then, with 15 grains of it mix 2 drachms of tartar, 2 drachms of table-salt, and 1/2 drachm of pulverized alum. Brighten the article to be plated with ley and prepared chalk, and rub on the mixture. When it has assumed a white appearance expose to heat, and then polish with the chamois or burnisher. Good for clock-dials and barometer scales. Silvering Metals, cold.--Mix 1 part of chloride of silver with 3 parts of pearl-ash, 1 1/2 parts common salt, and 1 part whiting. The article to be well cleaned, as before directed, and the mixture rubbed well on with a piece of cork moistened with water. When silvered wash the article in hot water, slightly alkalized; then wipe dry. Silvering by Heat.--Dissolve 1 oz. silver in nitric acid; add a small quantity of salt; then wash it and add salammoniac, or 6 ozs. of salt and white vitriol; also 1/4 oz. of corrosive sublimate; rub them together till they form a paste; rub the piece which is to be silvered with the paste; heat it till the silver runs, after which, dip it in weak vitriol pickle to clean it. Silvering Solution for Electro-plates.--Nitrate of silver 2 drachms, distilled water 37 drachms. Dissolve, and add salammoniac 1 drachm, hydrophosphite of soda 4 drachms, precipitated chalk 4 drachms. Agitate the preparation occasionally for 12 hours, when it will be ready for use. Apply with a fine sponge.
What Has Changed in the Last Century
When the Encyclopedia of Founding printed these recipes in 1892, silvering was a bench craft: you rubbed on pastes of silver chloride, cream of tartar and corrosive sublimate (mercuric chloride) with a cork or a brush, and cyanide of potassium was just another shelf bottle. Silver is still deposited electrolytically today, but in closed, ventilated plants under strict controls on cyanide and mercury, with non-cyanide and electroless baths now common, and the hand-rubbed amalgam and paste methods are gone from trade practice. Mirrors, once the great market for silvering, moved to vacuum-deposited aluminium from the 1930s, beginning with astronomical telescope mirrors. Silver plate on tableware also lost ground once stainless steel cutlery spread after the First World War.
Written for this edition, 2026.