SLUG TRAPS. 131 
which will be the case if they are not removed: after replacing them 
carefully, and altering the position of those that may be twisted or not 
laid out properly, put a heavy weight upon them, and keep it one week 
ina cool airy place; after this remove the weight and open the leaves, 
but not so as to derange the specimens, and Jet them dry off with the 
book closed; when they are perfectly dry, arrange them, and fasten 
them on sheets of paper with gum arabic dissolved in water. It is 
more difficult to dry stove than greenhouse plants, and it is very diffi- 
eult to dry Orchidee: our common Orchis, and many other British 
plants, are difficult to manage. I have succeeded well with Orchis 
and Cypripediums, by spreading about halfan inch of silver or common 
dry sand on a board quite level, laying a sheet of blotting paper on it. 
I then lay on the specimen and turn the upper part of the paper over 
it, and on the top add two or three (or more, if a very juicy specimen) 
sheets of paper; take an iron half heated, and press slowly and care- 
fully on the paper, so as to dry up the juices as fast as the heat drives 
them out: if too much heat is applied, so as to draw the juices too fast, 
they will return to the specimen, and turn it black ; when the principal 
part of the sap is drawn off, replace the specimen on dry sheets, pro- 
perly arrange the leaves and flowers, and apply double the quantity of 
heat; after drying the remaining moisture, leave the iron on the 
specimen till quite cold, and after exposure to the air for a day ina 
cool shady place, the process will be complete. Grasses are very easy 
to preserve, and only require attention as to the time of gathering ; 
this ought to be just before the flowers expand, as the pollen spoils 
them ; they only require dipping in hot water, and placing out between 
leaves, without any tissue or blotting paper. The same applies to the 
Ferns ; they want, especially some of the largest, a stronger or heavier 
weight to press them. Many of the Lichens and Mosses will not 
‘require pressing at all, at least most of those whose fructification lies 
in the bosom of the leaves, are spoiled by pressure ; others are larger, 
and it will be necessary slightly to press them, in order to make them 
Jay flat; it requires taste to lay them out on paper; the best plan is to 
throw them into pure water, which will open them out beautifully, 
and they may then be carefully laid on wet paper, and half dried before 
they are removed. The Algz may be beautifully dried in this way. 
The Lichens may be pressed a little harder, and it will add beauty to 
the eryptogamic collection, especially the little Cenomyce coccifera, 
whose little scarlet tips are as brilliant when dried, if gathered when 
fully developed, as they are on the heaths. 
SLUG TRAPS. 
I venture to send you the following letter, which I have just received 
from my brother, whose residence is about a mile from this place, not 
with a view to communicate a contrivance with which you are unac- 
quainted, but to show the great danger our gardeners will have to 
encounter if they are not admonished to adopt precautions in time 
against so destructive a pest, the vast numbers of which I attribute to 
the mildness and dampness of the winter. As far as my observation 
