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 passed 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 scrap-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 coarser 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.