In proceeding to dry the plants, procure a quantity of soft blotting-paper. Four or five sheets are to be laid down on the table (each folded within the other, as in a ream), and on the uppermost one the specimen is to be laid. Spread it out carefully, separating the branches and leaves so that they do not overlap; and after this is done, a slip of paper or "label" put beside the specimen, indicating its botanical name, the locality where collected, and the date when; then another four or five sheets, folded as before, are to be laid over the plant. On the surface of this latter layer of paper, another specimen or specimens may be spread--an additional layer of four or five sheets being placed over them--and so on until all the specimens collected are spread out. A board of the same size as the paper is to be placed above the uppermost sheet, and on the top of that a heavy weight, fifty or sixty pounds. A bundle of large volumes will serve the purpose of a weight, if no better is at hand. Some recommend a screw-press for pressing the plants, instead of a weight; but presses of all kinds are objectionable, as the shrinking of the plants renders the pressure unequal from the want of elasticity, which is so easily attained by means of an ordinary weight. After the specimens have been allowed to stand in this manner twenty-four hours or so, they should be taken carefully out; such leaves as are disarranged should be spread out properly, and the whole put into _dry_ paper, in the same way as in the previous operation. The moist paper from which they are taken should be spread before the fire to dry; it will be ready for use another time. The plants are to be supplied with dry paper, in this manner, once every twenty-four hours, until they have become quite dry, when they may be taken out and put apart in single sheets of gray paper.
The operation of _drying_ the specimens has been here described, but that of _mounting_ them on _white_ paper is equally important. Gum Arabic is generally used for this purpose, but it is very bad; does not adhere sufficiently, and thus allows the specimens to spring off from the sheets. Fine glue, prepared in a very thin state, is the best material for fixing the plants. The melted glue should, when very hot, be spread over the specimen carefully with a brush, a sheet of dirty absorbent paper lying beneath the specimen to prevent the glue soiling anything, and then the specimen is to be put down upon the sheet of white paper previously laid out for its reception. A towel is then taken to press the different branches or leaves gently down upon the surface of the paper. After this is done, a few sheets of drying paper are to be laid over the specimen, and on the top of this another sheet of white paper for the reception of another glued specimen, and so on until all are completed. A board is then to be placed over the whole, and a weight, in order to press all parts of the plants equally to the sheets of paper, until they are made firm by the drying of the glue. After the specimens have stood in this manner a few hours, they are to be taken out, their names, localities, and dates written at the bottom of the sheet, and the whole arranged in such manner as the possessor may think proper. Any refractory stems or branches that have sprung up from the paper in spite of the glue, may be fastened down by slips of gummed paper. The marginal portion of postage-stamp sheets supplies these to those who can obtain them in sufficient quantity.