Immediately the mirror is removed from the bath, the silvered surface should be well washed by allowing ordinary water to flow on it from a tap, for five minutes or more, then finally rinse with distilled water and place the mirror to dry with the silvered surface resting on some blotting paper. It is as well if the mirror can be left undisturbed for a day or two, as the film will be firmer, but it may be polished, if desired, after drying for a few hours.
To Polish the Silvered Surface.
Make a couple of polishing pads by filling two pieces of very soft wash-leather about six inches square loosely with cotton wool, and tie them into balls. Gently remove any dust that may have settled on the film with some loose cotton wool, and then go over it with one of the pads in small circular strokes for about 15 minutes. This will consolidate the film and fit it for polishing. Spread a little of the finest rouge on a sheet of writing paper, and impregnate the other pad with it. Go over the film with the rouged rubber with the same circular strokes till it is perfectly polished, which will take another 15 minutes or so. Never commence with the rouged pad, as the surface may be injured. When once the film has been consolidated it will remain so, and can be repolished many times with the rouged pad should it get tarnished. The pads should be kept from dust in wide-mouthed bottles for future use. With care the film will last for a long time, especially if it is not allowed to get damp, and consequently the mirrors should never be brought uncovered from the cold air to a warmer temperature.
The “flat” may be silvered and polished in the same way as the speculum, using a smaller appropriate vessel for the silvering solution.
To Separate the mirror from the Wooden Support.
Should the mirror be attached directly to its support, insert a chisel between them, when one or two gentle blows will cause them to separate, but, should the mirror be cemented to a block, stand the mirror on edge, when a slight tap on the block will detach it. Scrape off any pitch that remains on the back of the mirror, using finally some turpentine to wipe it clean. Great care should be taken not to finger the film.
Martin’s process for Silvering.
Prepare four solutions of any quantity. Keep in stoppered bottles.
Solution 1.—Dissolve 175 grains of pure nitrate of silver in 10 oz. of distilled water.