Xxx INTRODUCTION TO BOTANY. 
and of specimens, till you have either placed in paper all the specimens 
collected, or made a sufficiently thick pile. Cover the pile with one of the 
flat boards, and place upon it a heavy weight,—large stones or bags of 
sand answer perfectly. If travelling, leather straps and buckles, drawn 
tightly across the bundle, are used instead of weights. 
194. After the specimens have lain a day under pressure, the paper 
about them must be removed, and dry papers substituted ; and this process 
should be repeated at intervals of a day or two till the plants are perfectly 
dry. If many sheets of paper be placed between each layer of specimens, 
or if open frames be used instead of boards, the changes need not be so 
frequent. In changing it is not necessary to lift every specimen from the 
sheet on which it lies; but if a dry sheet be placed over the specimens, 
the latter, with the moist sheet, may be tilted over to the dry, and the 
moist sheet then removed, and this process repeated through the bundle. 
Much time and trouble may thus be saved. 
195. On the first day of shifting a sharp look-out should be kept for 
caterpillars, which are apt to secrete themselves in flowers, and, if not at 
once removed, will quickly destroy the specimens under pressure. 
196. In fine weather the bundles of specimens, weighted or strapped, 
may be exposed to the strongest heat of the sun; but as this causes a 
rapid extraction of moisture, in order to ensure its passing away, the 
plants must, on bringing in, and while still warm, be shifted into fresh 
papers: otherwise mouldiness and decay, and not exsiccation, will ensue. 
Artificial heat, not greater than 140°, may be substituted in wet weather. 
197. In drying plants within the tropics, and in all damp and hot 
climates, frequent shifting of papers is necessary; if neglected, the 
specimens will either fall to pieces, or become mouldy and rotten. 
198. Fleshy fruits should be preserved in spirits; or carefully stretched, 
and the seeds or hard parts dried. 
199. Succulent plants, Heaths, and plants with compound leaves (such as 
Mimosee), should be dipped (all but the flowers) for a few seconds into 
boiling water, before being placed in the drying-papers. This will Aid/ 
them, promote the drying of succulents, and prevent the Heaths, etc., 
from shedding their leaves. 
200. Plants with delicate corollas (Jridee, Oxalidee, etc.), should be 
placed between single leaves of very thin and soft, unglazed paper 
(filtering or tissue-paper). In shifting to dry papers the tissue-paper 
is not to be removed, but lifted with its contents to the dry layer. 
This will prevent the flowers from curling up or perishing. 
201. When the specimens are quite dry and stiff, a single sheet of paper 
is sufficient between each layer; they may be placed still more closely on 
the sheets, but not piled one on another; and, finally, in sending specimens 
from a distance, great care must be taken to protect the bundles, by 
sufficient covering, from the effects of external moisture, or from the 
attacks of insects. 
202. Having dried his plants, the student begins to form his Hlerba- 
rium, or Hortus Siccus. The first step is to assort the specimens, first 
into their classes ; then into subclasses, Orders, genera, and species. When 
this is done, he selects such specimens of such species as he wishes to 
retain for future reference, consigning the remainder to separate bundles 
labelled ‘“‘ duplicates,’ and keeping them for exchange with other 
botanists. : 
203. The specimens selected, having first been examined and named, 
are either fastened with thin glue to pieces of stiff white or cream-coloured 
cartridge-paper of a uniform size, or placed loosely, or secured by cross- 
bands or pins, in double sheets of soft paper. In either case the species 
belonging to each genus are placed within a common wrapper of strong 
