190 
Preparation of a Herbarium. 
cabinet ; and a dry room, without a constant fire, is re* 
commended as most suitable for a herbarium. 
The depredations of insects are peculiarly destruc- 
tive to dried specimens, and especially Ptinus fur, a 
small beetle, deposits its eggs in the germens or recep- 
tacles of flowers, which are in a short time devoured 
by the maggots when hatched. To prevent their de- 
vastations, Dr Smith recommends a solution of corro- 
sive sublimate of mercury in rectified spirits of wine, in 
the proportion of two drams to a pint, with the addi- 
tion of a little camphor, as the most efficacious remedy. 
When the specimens are quite dry, and before they are 
pasted, the solution is applied with a camel-hair pencil. 
It is also found useful to mix a few drops of the solu- 
tion with the glue which is employed for pasting the 
plants on the papers. This application. Dr Smith ob- 
serves, not only keeps off all kinds of vermin, but greatly 
revives the colours of most plants, and gives the collec- 
tion a pleasing air of freshness and neatness. 
Structure and Functions of Vegetables. 
The division of natural bodies into organised and in- 
organised, is sufficiently discriminative ; the most per- 
fect forms of inorganised matter exhibit no analogous 
characters to the varied and complicated structure of 
plants or animals. A striking diversity prevails in the 
mode of formation, or the growth and increase of the 
objects of these two great classes. In mineral bodies^ 
