CORRESPONDENCE. 343 
as possible. Blue flowers in general do not require heat; you may put them 
between sheets of plain white blotting-paper, five or six sheets on each side, 
passing the stalks and calyces, as directed above, through holes made in one of 
the thicknesses, and subject them to just suffioiont pressure to keep the flower 
from wrinkling. In the same manner, Ferns, white, and some variegated-leaved 
plants, such as Centaurea, Begonias, and Caladiums, may be treated. The 
fancy-leaved Geraniums require heat; but these, as well as other plants with 
variegated foliage produced by high cultivation, will often fail to repay the most 
careful treatment, as they are very apt to lose their distinctive markings under 
the drying process. For mounting the flowers you require a sheet of white 
cardboard, a pair of scissors or a penknife, gum, and a small camel-hair pencil. 
The gum must be very strong, and prepared as follows :—Take three ounces of 
arabic; pour upon it just sufficient hot water to dissolve it; then add a 
tablespoonful of spirits of wine. The greatest care and patience is required in 
the eoi hane of is: flowers; they must be taken up between the blade of 
your penknife and one finger. It is well to arrange them first on the card- 
board without ied. them, and, having arrived at a satisfactory effect, to 
fix the arrangement in your own sid ; then remove the flowers and proceed 
to build up your design, gumming the flowers one by one in the position you 
have assigned them. The smallest dab of gum in the middle of the back of the 
flower or leaf is sufficient to hold it in its place. A cardboard mount, round 
or oval, must now be placed on the cardboard on which the group is fixed, and 
the whole covered with a sheet of glass, and fastened round the edges so as to 
exclude the air. These groups may be framed as pictures, or mounted as fire- 
screens and table-tops. If hung up as a picture, it must be on a wall looking 
north; and, however they are , care must be taken that 2 sun's rays 
shall not rest upon them. They must also be kept free from dam 
CORRESPONDENCE. 
On a Poisoning Solution for Botanical Specimens. 
sida en. in e strength of the poisoning solutions for her- 
1 in the various botanical text-books commonly 
barium 
in use by students, Thus, I Desvaux and De Cando lle adaa spirits of wine 
wholly, Lindley the same, half saturated with c limate, which latter 
proportion ooa amroely } be aam nud than a seventh or e eighth. « the weight 
of the spirit ; 
of sublimate to the litre of spirit (— 231-5103 gne. troy to 177608 i imp. snis ; 
Duchartre, a solution of double this strength; whilst Balfour recommends half 
a drachm of sublimate to each ounce of camphorated spirit or naphtha. 
Dried ts are unusually subject to the attacks of insects in southern 
China, especially during the south-west monsoon, when the temperature is 
