Silver Nitrate. (e) Wash in solution of 10 parts potassium iodide, 1 iodine, 1 ammonia, in 100 water. (Liesegang.)
(f) Wash in strong solution of cupric chloride, and, about a minute later, in soda hyposulphite. (Underwood.)
Nitric Acid. (g) Wash immediately and put on some lime chloride.
(h) On the stain or stains place sufficient caustic soda (the usual reagent strength) with the end of the stopper (if the stain is all covered it will do); gently rub it with any solid for a few seconds, then wash it off; then gently rub the spot with a finger nail, when it will come off almost completely; put on a little dilute hydrochloric acid, when the spot will disappear entirely. If not, repeat the whole process, which will be sure to remove it without the least injury to the hand.
(i) Wash the hands in a solution of soda-ash and bleaching powder, add the solution of soda-ash to the bleaching liquor as long as a precipitate forms, then wash; the remaining stains will wear off in time. Wash in this daily till the stains are completely removed.
Potassium Bichromate. (k) Rub the stains with a solution of sulphurous acid, and subsequently wash with distilled or soft water. (l) To a warm, strong solution of soda hyposulphite add a small quantity of sulphuric acid; this may then be used on the stains with similar effect. (Photo. News.)
Ivory and Bone Articles.—(a) Spirit of turpentine is very efficacious in removing the disagreeable odour and fatty emanations of bones or ivory, while it leaves them beautifully bleached. The articles should be exposed in the fluid for 3 or 4 days in the sun, or a little longer if in the shade. They should rest upon strips of zinc, so as to be a trifle above the bottom of the glass vessel employed. The turpentine acts as an oxidising agent, and the product of the combustion is an acid liquor which sinks to the bottom, and strongly attacks the ivory if allowed to touch it.
(b) Make a thick puddle of common whiting in a saucer. Brush well with a tooth-brush into the curved work. Brush well out with plenty of clean water. Dry gently near the fire. Finish with a clean dry hard brush, adding one or two drops (not more) of sweet oil.
(c) Mix about a tablespoonful of oxalic acid in ½ pint boiling water. Wet the ivory over first with water, then with a tooth-brush apply the acid, doing one side at a time, and rinsing; finally dry in a cloth before the fire, but not too close.