Hold oiled paper in the smoke of a lamp or of pitch, until it becomes coated with the smoke; to this paper apply the leaf of which you wish an impression, having previously warmed it between your hands, that it may he pliable. Place the lower surface of the leaf upon the blackened surface of the oil-paper, that the numerous veins, which are so prominent on this side, may receive from the paper a portion of the smoke. Lay a paper over the leaf, and then press it gently upon the smoked paper with the fingers, or with a small roller covered with woollen cloth, or some similarly soft material, so that every part of the leaf may come in contact with the sooted oil-paper. A coating of the smoke will adhere to the leaf. Then remove the leaf carefully, and place the blackened surface on a sheet of white paper, or in a book prepared for the purpose, covering the leaf with a clean slip of paper, and pressing upon it with the fingers, or roller, as before.

Thus may be obtained the impression of a leaf, showing the perfect outlines, together with an accurate exhibition of the veins which extend in every direction through it, more correctly than the finest drawing. And this process is so simple, and the materials so easily obtained, that any person, with a little practice to enable him to apply the right quant.i.ty of smoke to the oil-paper, and give the leaf a proper pressure, can prepare beautiful leaf impressions, such as a naturalist would be proud to possess.

2336. Dry Botanical Specimens for Preservation.

The plants to be preserved should be gathered when the weather is dry.

Place the ends in water, and let them remain in a cool place till the next day. When about to be submitted to the process of drying, place each plant between several sheets of blotting paper, and iron it with a large smooth heater, pretty strongly warmed, till all the moisture is dissipated. Colours may thus be fixed, which otherwise become pale, or nearly white. Some plants require more moderate heat than others, and herein consists the nicety of the experiment; but it is generally found that if the iron be not too hot, and is pa.s.sed rapidly yet carefully over the surface of the blotting paper, it answers the purpose equally well with plants of almost every variety of hue and thickness.

In compound flowers, with those also of a stubborn and solid form, as the Centaurea, some little art is required in cutting away the under part, by which means the profile and forms of the flowers will be more distinctly exhibited. This is especially necessary when the flowers are fixed down with gum upon the paper previous to ironing, by which means they become almost incorporated with the surface. When this very delicate process is attempted, blotting-paper should be laid under every part excepting the blossoms, in order to prevent staining the white paper. Great care must be taken to keep preserved specimens in a dry place.

2337. Collecting and Laying out Sea-weeds.

"First wash the sea-weed in fresh water, then take a plate or dish (the larger the better), cut your paper to the size required, place it in the plate with fresh water, and spread out the plant with a good-sized camel-hair pencil in a natural form (picking out with the pin gives the sea-weed an unnatural appearance, and destroys the characteristic fall of the branches, which should be carefully avoided); then gently raise the paper with the specimen out of the water, placing it in a slanting position for a few moments, so as to allow the super-abundant water to ran off; after which, place it in the press. The press is made with either three pieces of board or pasteboard. Lay on the first board two sheets of blotting-paper; on that lay your specimens; place straight and smooth over them a piece of old muslin, fine cambric, or linen; then some more blotting-paper, and place another board on the top of that, and continue in the same way.

"The blotting-paper and the muslin should be carefully removed and dried every day, and then replaced; at the same time, those specimens that are sufficiently dried may be taken away. Nothing now remains but to write on each the name, date, and locality. You can either gum the specimens in a sc.r.a.p-book, or fix them in, as drawings are often fastened, by making four slits in the page, and inserting each corner. This is by far the best plan, as it admits of their removal, without injury to the page, at any future period, if it be required either to insert better specimens, or intermediate species.

"Some of the large algae will not adhere to the paper, and consequently require gumming. The following method of preserving them has been communicated by a botanical friend:

'After well cleaning and pressing, brush the coa.r.s.er kinds of algae over with spirits of turpentine, in which two or three small lumps of gum mastic have been dissolved, by shaking in a warm place; two-thirds of a small phial is the proper proportion, and this will make the specimens retain a fresh appearance.'"

_Miss Gifford's Marine Botanist_.

2338. To Preserve Fungi.

Receipt of the celebrated botanist, William Withering, by which specimens of fungi may be beautifully preserved.

"Take two ounces of sulphate of copper, or blue vitriol, and reduce it to powder; pour upon it a pint of boiling water; and when cold, add half a pint of spirits of wine; cork it well, and call it 'the pickle.' To eight pints of water, add one pint and a half of spirits of wine, and call it 'the liquor.' Be provided with a number of wide-mouthed bottles of different sizes, all well fitted with corks.

The fungi should be left on the table as long as possible, to allow the moisture to evaporate; they should then he placed in the pickle for three hours, or longer, if necessary; then place them in the bottles intended for their reception, and fill with the liquor. They should then be well corked and sealed, and arranged in order, with their names in front of the bottles."

[TRUST NOT THE MAN WHO PROMISES WITH AN OATH.]

2339. To Stuff Birds, Quadrupeds, &c.

Large animals should be carefully skinned, with the horns, skull, tail, hoofs, &c., entire. Then rub the inside of the skin thoroughly with the mixture of salt, pepper, and alum, and hang up to dry. Large birds may be treated in the same way, but should not be put into spirits.

2340. Small Birds may be preserved as follows:

Take out the entrails, open a pa.s.sage to the brain, which should be scooped out through the mouth; introduce into the cavities of the skull and the whole body, some of the mixture of salt, alum, and pepper, putting some through the gullet and whole length of the neck; then hang the bird in a cool, airy place--first by the feet, that the body may be impregnated by the salt, and afterwards by a thread through the under mandible of the bill, till it appears to be free from smell; then hang it in the sun, or near a fire: after it is well dried, clean out what remains loose of the mixture, and fill the cavity of the body with wood, oak.u.m, or any soft substance, and pack it smooth in paper.

2341. Birds' Eggs.

In selecting eggs for a cabinet, always choose those which are newly laid; make a medium-sized hole at the sharp end with a pointed instrument, and one at the blunt end: let this last hole be as small as possible; this done, apply your mouth to the blunt end, and blow the contents through the sharp end. If the yolk will not come freely, run a pin or wire up into the egg, and stir the yolk well about; now get a cupful of water, and immersing the sharp end of the sh.e.l.l into it, apply your mouth to the blunt end and suck up some of the water into the empty sh.e.l.l; then put your finger and thumb upon the two holes, shake the water well within, and after this, blow it out. The water will clear the egg of any remains of yolk or of white which may stay in after blowing. If one injection of water will not suffice, make a second or third.

An egg, immediately after it is produced, is very clear and fine; but by staying in the nest, and coming in contact with the feet of the bird, it soon a.s.sumes a dirty appearance. To remedy this, wash it well in soap and water, and use a nail-brush to get the dirt off. The eggsh.e.l.l is now as it ought to be, and nothing remains to be done but to prevent the thin white membrane (which is still inside) from corrupting.

Take a winegla.s.s and fill it with a solution of corrosive sublimate in alcohol, then immerse the sharp end of the eggsh.e.l.l into it, keeping the finger and thumb which hold the egg just clear of the solution.

Apply the mouth to the little hole at the blunt end, and suck up some of the solution into the sh.e.l.l. There need be no fear of getting the liquor into the mouth, for as soon as it rises in the sh.e.l.l the cold will strike the finger and thumb, and then the sucking must be immediately discontinued. Shake the sh.e.l.l in the same manner as when the water was in it, and then blow the solution back into the gla.s.s.

The eggsh.e.l.l will now be beyond the reach of corruption; the membrane for ever retains its pristine whiteness, and no insect, for the time to come, will ever venture to prey upon it. If you wish your egg to appear extremely brilliant, give it a coat of mastic varnish, put on very sparingly with a camel-hair pencil: green or blue eggs must be done with gum arabic, as the mastic varnish is apt to injure the colour.

2342. Fishes.

Large fishes should be opened in the belly, the entrails taken out, and the inside well rubbed with pepper, and stuffed with oak.u.m. Small fishes may be put in spirit, as well as reptiles, worms, and insects (except b.u.t.terflies and moths); insects of fine colours should be pinned down in a box prepared for that purpose, with their wings expanded.

2343. Tracing Paper.

Mix together by a gentle heat, one ounce of Canada balsam, and a quarter of a pint of spirits of turpentine; with a soft brush spread it thinly over one side of good tissue paper. The composition dries quickly, is very transparent, and not greasy, and therefore, does not stain the paper to which it is applied.

[NEVER WALK ONE WAY AND LOOK ANOTHER.]

2344. Impressions from Coins.

Melt a little isingla.s.s glue with brandy, and pour it thinly over the medal, &c., so as to cover its whole surface; let it remain on for a day or two, till it has thoroughly dried and hardened, and then take it off, when it will be fine, clear, and hard, and will present a very elegant impression of the coin. It will also resist the effects of damp air, which occasions all other kinds of glue to soften and bend if not prepared in this way.

2345. Method of Hardening Objects in Plaster of Paris.

Take two parts of stearine, two parts of Venetian soap, one part of pearlash, and twenty-four to thirty parts of a solution of caustic potash. The stearine and soap are cut into slices, mixed with the cold lye, and boiled for about half an hour, being constantly stirred.

Whenever the ma.s.s rises, a little cold lye is added. The pearlash, previously moistened with a little rain water, is then added, and the whole boiled for a few minutes. The ma.s.s is then stirred until cold, when it is mixed with so much cold lye that it becomes perfectly liquid, and runs off the spoon without coagulating and contracting.

Previously to using this composition, it should be kept for several days well covered. It may be preserved for years.

Before applying it to the objects, they should be well dusted, the stains sc.r.a.ped away, and then coated, by means of a thick brush, with the wash, as long as the plaster of Paris absorbs it, and left to dry.

The coating is then dusted with leather, or a soft brush. If the surface has not become shining, the operation must be repeated.

2346. Modelling.

Modelling in Cork, Gutta Percha, Leather, Paper, Plaster of Paris, Wax, Wood, &c.--Modelling, in a general sense, signifies the art of constructing an original pattern, which is to be ultimately carried out on an enlarged scale, or copied exactly.

2347. Scale of Construction.

When models are constructed to give a miniature representation of any great work, elevation, or topographical information, they are executed in detail, with all the original parts in just and due proportions, so that the work may be conducted or comprehended better; and if the model is a scientific one, viz., relating to machinery, physical science, &c., then it requires to be even still more accurate in its details. In fact, all models should be constructed on a scale, which should be appended to them, so that a better idea may be obtained of the proportions and dimensions.

2348. Materials.