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wire in connection with the copper end of the battery must also be inserted into the copper solution facing the gutta percha, bat not touching it; this not only acts as a conductor to the electricity, but also maintains the solution of copper of a permanent strength. In a short time the copper will be found to creep over the whole surface of the gutta percha, and in about twenty-four hours a thick deposit of copper will be obtained, which may then be detached from the mould. The accuracy with which a leaf may thus be cast is truly surprising. The Editor has in his possession a cast of a hazel leaf made by this process, which nobody would take to be a production of art. Every fibre and nerve, in fact, the minutest part is delineated with the utmost fidelity.

2090. Leaf Printing. After warming the leaf between the hands, apply printing ink, by means of a small leather ball containing cotton, or some soft substance, or with the end of the finger. The leather ball (and the finger, when used for that purpose), after the ink is applied to it, should be pressed several times on a piece of leather, or some smooth surface, before each application to the leaf, that the ink may be smoothly and evenly applied. After the under surface of the leaf has been sufficiently inked, apply it to the paper where you wish the impression to be; and, after covering it with a slip of paper, use the hand or roller to press upon it.

2091. Directions for Taking Leaf Impressions. - 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 be pliable. Place the lower surface of the leaf upon the olackened 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, not ruled, 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 quantity 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. There is another, and we think a better method of taking leaf_impressions, than the preceding one. The only difference in the process consists in the use of printing ink, instead of smoked oil-paper.

The

2092. Dry Botanical Specimens for Preservation. plants you wish to preserve should be gathered when the weather is dry, and after placing the ends in water, 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 passed rapidly yet carefully over the surface of the blotting paper, it answers the purpose equally well with plants of

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rub the inside of the skin thoroughly with a 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.

2096. Small Birds may be preserved as follows:-Take out the entrails, open a passage 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 placefirst 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 wool, oakum, or any soft substance, and pack it smooth in paper.

2097. Birds' Eggs.-In selecting eggs for a cabinet, always choose those which are newly laid; make a mediumsized 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 shell into it, apply your mouth to the blunt end and suck up some of the water into the empty shell; 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 your 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

To

soon assumes a dirty appearance. remedy this, wash it well in soap and water, and use a nail-brush to get the dirt off. The eggshell 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 wineglass and fill it with a solution of corrosive sublimate in alcohol, then immerse the sharp end of the eggshell into it, keeping your finger and thumb, as you hold it, just clear of the solution; apply your mouth to the little hole at the blunt end, and suck up some of the solution into the shell; you need not be fearful of getting the liquor into your mouth, for as soon as it rises in the shell the cold will strike your finger and thumb, and then you cease sucking; shake the shell just as you did when the water was in it, and then blow the solution back into the glass. The eggshell 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; the mastic varnish is apt to injure the colour.

2098. Fishes.--Large fishes should be opened in the belly, the entrails taken out, and the inside well rubbed with pepper, and stuffed with oakum. Small fishes may be put in spirit, as well as reptiles, worms, and insects (except butterflies and moths); insects of fine colours should be pinned down in a box prepared for that purpose, with their wings expanded.

2099. 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. It dries quickly, is very transparent, and is not greasy, therefore does not stain the object upon. which it may be placed.

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sentation 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

2101. 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 ley, and boiled for about half an hour, being constantly stirred. Whenever the mass rises, a little cold ley is added. The pearlash, previously moistened with a little rain water, is then added, and the whole boiled for a few minutes. The mass is then stirred until cold, when it is mixed with so much cold ley 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 scraped 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.

2102. 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.

2103. WHEN MODELS ARE CONSTRUCTED to give a miniature repre

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.

2104. THE MATERIALS REQUIRED are plaster of Paris, wax, whiting, putty, clay, pipeclay; common and factory cinders; sand of various colours; powdered fluor spar, oyster-shells, bricks, and slate; gums, acacia and tragacanth; starch; paper, white and brown, cardboard and millboard; cork sheets, cork raspings, and old bottle-corks; gutta percha; leather and leather chips; wood; paints, oil, water, and varnish; moss, lichen, ferns, and grass; talc, window and looking-glass; muslin and net; chenille; carded wool; tow; wire; hay and straw; various varnishes, glue and cements.

2105. THE TOOLS consist of brushes for paints, varnishes, and cements; two or three bradawls; a sharp penknife; a chisel, hammer, and punches; scissors, and pencil.

MODELLED

2106. CAVES MAY BE readily in cork, wood, starch-paste, or cinders covered with brown paper soaked in thin glue.

2107. TO CONSTRUCT THEM OF CINDERS.-Arrange the cinders, whether common or factory, in such a manner as to resemble the intended design; then cover in such parts as require it with brown paper soaked in thin glue until quite pulpy. When nearly dry, dust over with sand, powdered brick, slate, and chopped lichen or moss, from a pepper-box; touch up the various parts with either oil, water, or varnish colours; and if necessary, form your trees of wire, covered with brown paper and moss, glued on.