ON PRESERVATION OF PLANTS FOR EXHIBITION. 695 
I have also resorted to it with advantage in preparing succulent plants 
that are difficult to kill and to free of moisture, and also in lessening the 
tendency to the fall of the leaves in certain plants, such as Hrica. 
(Exposure to Vapour of Chloroform, Ether, or other poisonous gases till 
the plants are dead serves the same ends.) 
Colouring or Staining.—I have employed this to bring into greater 
clearness the course of the bundles, but not to any great extent. Red or 
purplish-red flowers will retain their colour, or more often be coloured 
more brightly than natural, if dipped, before they are pressed, into a 
mixture of one part hydrochloric acid in four of spirit. 
Drying Fungi.—I have tried the method devised by Mr. English ; but 
my results have not been satisfactory, though the form has in a good 
many been fairly well preserved. Hard fungi dry easily and well if exposed 
to air in a dry place. 
Movuntine PREPARATIONS. 
Dry Preparations, including Herbarium Specimens. 
Fixing to paper is done with fish-glue. The simplest and quickest 
method I find to be as follows :—A sheet of plate glass slightly larger 
than the herbarium sheet has a thin layer of glue smeared uniformly over 
it. The plant is then laid on this, and is pressed gently. Thus each part 
that will touch the paper has received a little of the glue, and on the 
specimen being laid on the paper it adheres wherever it should do so, and 
no other part is smeared. Of course this method is not suited for weak 
plants that could not be lifted without injury. The specimens after 
having been glued are placed under pressure for some hours. 
Special dissections, seeds, and other small portions I place in a special 
envelope on the sheet, or under a piece of mica or of the gelatine used in 
Christmas crackers. 
Preparations in Boxes are also fixed with fish-glue usually, unless the 
surface of attachment is very small, in which case they are secured by 
threads or wires to the bottom of the box. 
Preparations in Fluids.—Photoxylin has been found to give sufficiently 
good results with many small objects, the slight opacity that is apt to 
“ae not being a serious objection to its use. Gelatine is used for larger 
objects. 
Silk Thread has also proved very useful for some kinds of objects, 
allowing them to be easily fixed to mica or glass tablets, or to strips of 
hard paraffin, which do well sometimes. To the paraffin the specimens 
can sometimes be fixed conveniently by the use of a hot rod or wire to 
melt it at the point of contact. Ihave recently used xylonite for supports, 
but have scarcely had sufficient experience of it to warrant a definite 
conclusion. It appears to do best in solutions of formalin. Black xylonite 
loses its colour in spirit. 
Poisoninc Dry PREPARATIONS. 
Mercuric Chloride is the substance of which I make most use for 
poisoning herbarium specimens, and also for disinfecting specimens and 
jars for fluid preparations. The herbarium specimens are most con- 
veniently treated by dipping them into the solution, of the usual strength, 
in a shallow earthenware dish, handling them with wooden forceps, and 
placing them till quite dry under pressure between sheets of paper. 
