HORTUS siccus, a dry garden, an ap pellation given to a collection of speci mens of plants, carefully dried and pre served. The value of such a collection is 'very evident, since a thousand minutia: may be preserved in the well-dried spe cimens of plants; which the most accurate engraver would have omitted. We shall, therefore, give some methods of drying and preserving an hortus siccus. Speci mens ought to be collected when dry, and carried home in a tin box. Plants may be dried by pressing in a box of sand, or with a hot smoothing iron. Each of these has its advantages. If pressure be employed, a botanical press may be procured. The press is made of two smooth boards of hard wood, eighteen inches long, twelve broad, and two thick. Screws must be fixed in each corner with nuts. If a press cannot easily be had, books may be employed. Next some quires of unsized blotting paper must be provided. The specimens, when taken out of the tin box, must be carefully spread on a piece of pasteboard, covered with a single sheet of the paper quite dry ; then place three or four sheets of the same paper above the plant, to im bibe the moisture as it is pressed out ; it is then to be put into the press. As many plants as the press will hold may be piled up in this manner. At first they ought to be pressed gently. After being pressed for twenty-four hours or so, the plants ought to be examined, that any leaves or petals which have been folded may be spread out, and dry sheets of paper laid over them. They may now be replaced in the press, and a greater degree of pressure applied. The press ought to stand near a fire, or in the sunshine. Af ter remaining two days in this situation, they should be again examined, and dry sheets of paper be laid over them. The pressure then ought to be considerably increased. After remaining three days longer in the press, the plants may be taken out, and such as are sufficiently dry may be put in a dry sheet of writing pa per. Those plants which are succulent may require more pressure, and the blos som paper again renewed. Plants which
dry very quickly, ought to be pressed with considerable force when first put into the press ; and if delicate, the blos som paper should be changed every day. When the stem is woody, it may be thin ned with a knife, and if the flower be thick or globular, as the thistle, one side of it may be cut away, as all that is neces sary, in a specimen, is to preserve the character of the class, order, genus, and species. Plan's may be dried in a box of sand in a more expeditious manner, and this method preserves the colour of some plants better. The specimens, after be ing pressed fur ten or twelve hours, must be laid within a sheet of blossom paper. The box must contain an inch deep of fine dry sand, on which the sheet is to be placed, and then covered with sand an inch thick; another sheet may then be de posited in the same manner, and so on, till the box be full. The b( x must be placed near a fire for two or three days. Then the sand must be carefully remov ed, and the plants examined. if not suf ficiendy dried, they may again be replac ed in the same manner for a day or two. In drying plants with a hot smoothing iron, they must be placed within several, sheets of blotting paper, and ironeu till they become sufficiently dry. This me thod answers best for drying succulent and mucilaginous plants. When proper ly dried, the specimens should be placed in sheets of writing-paper, and may be slightly fastened by making the top and bottom of the stalk pass through a slip of the paper, cut nearly for the purpose.— Then the name of the genus and species should be written down, the place where it was found, nature of the soil, and the season of the year. These specimens may be collected into genera, orders, and classes, and titled and preserved in a port folio or cabinet. The method of preserv ing many of the cryptogamous plants is more difficult, on account of the greater quantity of moisture which they con tain, and the greater delicacy of their texture.