Resin Bubbles.—If the end of a copper tube or of a tobacco pipe be dipped in melted resin at a temperature a little above that of boiling water, taken out and held nearly in a vertical position, and blown through, bubbles will be formed of all possible sizes, from that of a hen’s egg down to sizes which can hardly be seen. These bubbles have a very pleasing appearance and are permanent.
Etching on Glass.—Cover the glass with a thin coat of beeswax, and draw your design with a needle cutting down through the wax to the surface of the glass. Place the glass in a shallow bath, and cover it evenly with fluor-spar to the depth of an eight of an inch. Now pour sulphuric acid diluted with three times its weight of water upon the spar. Let this remain three or four hours. Pour away the acid, remove the spar, and clean the glass with turpentine, and your design will be found upon the glass.
How to make Carbon Paper.—Carbonic paper for use with order books, and for other purposes, is made as follows: Cold lard well mixed with lamp-black is well rubbed into the paper with a soft piece of cotton rag. When evenly and thoroughly done, wipe the surface gently with flannel until the colour ceases to come off; it is then ready for use. To obtain similar papers but of other colours, substitute ordinary paint powders for the lamp-black. The most suitable colours will be found to be Venetian red, Prussian blue, chrome green.
The Making of Paste.—There are so many occupations with which boys amuse themselves that need paste that we have included a few recipes.
A Simple Paste.—For a breakfast cup full of a simple paste, needed for use at the moment, and not required to be kept for many days, take a heaped tablespoonful of flour. Mix it thoroughly with cold water as though you were mixing mustard, then fill the cup with boiling water, pour the whole into a saucepan, and let it boil gently for a few minutes. It is then ready for use. You may use starch instead of flour.
A Large Quantity that will Last.—In a quart of water dissolve a teaspoonful of pure powdered alum. Into this stir as much flour as will make a thick cream, and keep on stirring until the mixture is smooth and until every lump has been removed. Thoroughly mix with this a teaspoonful of powdered resin, and into this mixture pour a cup of boiling water. Keep on stirring, and if the mixture does not thicken from the action of the boiling water assist it to thicken by placing it upon the fire for a minute or two. Afterwards add a few drops of oil of cloves to preserve it from going sour. Pour the paste into some vessel that has a cover, and keep it covered and in a cool place. In this form it will be thicker and stronger than is necessary for general use, but take a little as you need it and reduce it to its right consistency with warm water.
Rice Glue.—Mix rice flour well with cold water, then simmer it gently over the fire. This makes a fine kind of paste, durable and effective. Mixed thickly it may be used as a modelling clay, and when it is dry it takes a high polish.
Dressing the Skins of Small Animals.—Different dressings have been recommended, most of which contain arsenic or corrosive sublimate, which are deadly poisons; but really all that is necessary is simple alum, a pound of which can be bought for three-halfpence. Stretch the skin fur downwards on a board, and fasten it with tacks. Put powdered alum over it, and rub it in well. Continue to do this every two or three days for a fortnight. Then remove the alum, and with a knife scrape carefully off any bits of flesh or fat that may be left on the skin. When dried, to render it soft, rub a little yolk of egg or oil into it, and draw it backwards and forwards across the edge of a blunt knife, fixed for the purpose. Drawing through a ring, or well rubbing between the hands will also serve to soften it.
Casts of Medals and Coins.—Cut a strip of brown paper about six inches long by one inch deep. Rub a little oil or grease all over that side of the coin you wish to reproduce, cleaning off all superfluous grease with a little cotton wool, but still leaving the surface greased. Then roll the paper round the edge of the coin so that it resembles a pill-box with a metal bottom, and fix the loose end with a dab of sealing wax. Into this pour a mixture of plaster of Paris and water made to the consistence of cream, tapping the box lightly on the table to cause the plaster to settle down free from bubbles. When the plaster is set quite hard, strip off the paper, and you have your plaster mould. By soaking this with oil and fastening a strip of paper round it as round the coin, you have a complete mould into which you can pour plaster and so take a cast exactly like the original except in colour, which however may be imitated with water colours. Another plan is to make the mould of a different substance, such as isinglass; thoroughly dissolve isinglass in spirits of wine, then pour upon the coin as before, and set aside for a day or two. When quite hard it will separate easily and be found as clear as a bit of glass.
Removal of Ink Blots.—Ink-blots can be removed from paper by painting over with a camel-hair brush dipped in a solution of 2 drachms muriate of tin in 4 drachms of water. When the ink has quite disappeared, rinse the paper in clean water; then dry it.