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.
2334. 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.
2335. 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 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 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.
2336. Dry Botanical Specimens for Preservation