74
SUGGESTIONS FOR THE FORMATION
have always found that such straps give ample pressure, and at
the same time have an elasticity which preserves the plant from
crushing. A special kind of paper is made for drying plants,
which is best for the purpose. It is sold at 23s. per ream by
Messrs. West, Newman & Co., 54, Hatton Garden. Any unsized
paper may however be used, for instance the bibulous paper used
by grocers for wrapping moist sugar in is an economical substitute.
The size of the paper should be 20 in. x 12 in., or, better, twice
that size, doubled.
The plants should be carefully laid out in order to preserve their
natural form, and be so disposed in the press that the pressure is
equalized, avoiding putting all the thick parts in the centre. Sheets
of cotton wool may be found convenient to preserve uniform pres-
sure between the thick parts of plants. It is well to envelop delicate
flowers in tissue-paper which need not be removed until the drying
is done. Several sheets of paper should be laid between each
plant, the number of sheets depending upon the succulence of the
plant.
The papers should be changed daily for the first few days ; when
first changed any leaves or flowers bent or displaced should be
adjusted and the plant may be thinned out if necessary, but great
care must be taken to preserve as far as possible the natural appear-
ance of the plant. As the drying proceeds longer intervals may elapse
between the changes of paper ; in some cases it may be found neces-
sary to split or hollow out the thick root or stem of a plant. When
many plants are in the press at one time it will be well to interpose
ventilators. These ventilators should be 20 in. x 12 in. and may be
made out of splines of wood half-inch wide and one-tenth of an inch
thick crossed to form a lattice, each spline being nine-sixteenths of
an inch apart.
Some succulent plants retain their vitality so much that it is
necessary to immerse them for some seconds or minutes in water at
a temperature of 212o Fahr. before placing them in the press. I
have a specimen of a Sedum so treated, and also oven dried, but
which after mounting sent out a shoot some inches in length.
Many plants invariably change their colour in drying, such as
Melampyrum, Orobanche, &c. It is stated that this may be pre-
vented by immersion for some seconds in equal parts of sulphurous
acid and methylated spirits of wine. By cutting off the flowering
heads of orchids, and thus enabling the sap readily to escape, it