OF THE HERBARIUM. 
195 
other of the numerous ills to which a * Hortus Siccus ’ is 
exposed ; because it is mainly due to neglect, to leaving 
the specimens to take care of themselves, that insects are 
encouraged in their depredations. The student may have 
an intense affection for his botanical treasures; he may 
handle them tenderly, when extracting some much-prized 
example ; he may see that the room is duly warmed to pre- 
vent the admission of damp with its accompanying swarm 
of minute Fungi ; but all his labour and love will be throwr 
away, if he be not constantly on the watch, turning ovea. 
the sheets, and examining his favourites individually, 
scrutinising their condition, and looking with an almost 
microscopic eye for the first traces of the enemy. 1 Prin- 
cipiis obsta ’ should be the motto inscribed over the portals 
of his cabinet. He must strive to prevent the fiend from 
entering his paradise at all ; for if once he and his progeny 
gain a footing there, it will cost him many a weary hour’s 
hard work to eradicate them. 
As a means to this end, no plant, whether dried by 
himself, or communicated from some other source, should 
be introduced into the herbarium without first undergoing 
a strict investigation. Indeed, if a number 01 specimens 
are received in bad condition, it is always as well to 
£ sulphur ’ them, according to the plan given below, to 
prevent the possible infection of the whole cabinet. A 
world of future trouble and vexation will be saved, by 
taking care, in the first instance, that no ova or larvag are 
concealed among the leaves or in the flower -heads. 
Another necessary precaution is to 1 poison ’ the speci- 
mens before laying them by. Frequent experiments have 
been made in this direction, with the view of discovering 
some means of warding off the attacks of the insect world, 
or at least of rendering them harmless. Not one of the 
numerous methods, however, can be pronounced absolutely 
certain in its operation. Many of the lower forms of 
plants, the Alga*, the Lichens, and the Mosses are, compara- 
tively speaking, exempt from their ravages ; but they seen* 
