Improvements in or relating to the Treatment and Preservation of Plants, Leaves, and the like.
Year: 1897

page_text: Date of Application, 18th June, 1897-Accepted, 21st Aug., 1897
Improvements in or relating to the Treatment and Preservation of
Plants, Leaves, and the like.
A communication from RICHARD LEO KEFERSTEIN and KARL RUDOLF KEFERSTEIN, of
17 Polierstrasse, Dresden, in the Empire of Germany, Manufacturers.
I, ALFRED JULIUS BOULT of 111 Hatton Garden, in the County of Middlesex,
Chartered Patent Agent do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
It is a well-known procedure to prepare or preserve plants leaves and the like,
especially ferns and palms, by soaking them in hot water or an alkaline lye, by
impregnating them with glycerine or other (preferably hygrosopic) substances and by
dyeing or painting them or dyeing and painting, so that they have the appearance
and suppleness of fresh plants, but last much longer.
The new process serves for the same purpose and impregnating with glycerine or
equivalent and dyeing or painting are also used; but it is characterised by the tedious
treatment-which has to be continued for hours-with, hot water or alkaline lye
being replaced as far as it is not employed simply for cleaning the plants-by a
treatment with diluted sulphuric or similarly acting acid, which takes only a few
minutes or fractions of minutes.
The action of the acid is quick and produces a thorough softening or dissolution of
the natural armour or covering of silicic acid of the plants. The more silicic acid the
skin of a leaf contains, the stronger must be the acid used or the longer must be the
duration of the treatment. Fixed figures applicable in all cases cannot be given, as
the strength of the acid and time of treatment depends not only on the contents of
silicic acid in a given plant but also on the condition of the leaves, their age etc.;
the operator soon learns to know the proper strength and length of treatment
necessary. As regards the expression "diluted sulphuric acid" it must be pointed
out that the ordinary sulphuric acid as it is put on the market, must be considered as
diluted, that is to say not free from water; but it would hardly do to use it without
further dilution unless for plants having a very great proportion of silicic acid.
Besides the gain of time by the sulphuric acid treatment, there is further gain of
time in dyeing owing to the fact that dyeing and impregnating with glycerine or
equivalent can be effected simultaneously in one bath and, owing to the previous
use of sulphuric acid, this treatment also takes a very short time. The dye and
glycerine are absorbed almost simultaneously. The whole process lasts when a dyeing
bath is used, only a few hours as far as it requires the constant attendance of a
workman.
Another advantage is that the product presents a much more life-like appearance.
The reasons for this are two fold. A greater suppleness of the leaves is obtained
(their strength being at least the same as before) with either unpainted or painted
leaves. When the leaves are dyed in a bath the new process affords an additional
advantage in that owing to a better absorption of the dyes, say aniline dyes, a really

page_text: whereas hitherto in spite of the application of the bath for several hours it has been
possible to obtain only a heavy blue-green unnatural colour.
The process is carried out preferably as follows:-
A. WHEN A DYE BATH IS USED.
(a) The dry parts of plants are washed with water if necessary and then dipped
for a very short time into inore or less diluted sulphuric or similarly acting acid until
they become sufficiently soft.
(b) Washed in water..
(c) Partly dried. Then they are placed
(d) into a combined dye and glycerine bath, consisting of aniline dyes and
glycerine (or syrup, molasses or other more or less hygrosopic substances capable of
being absorbed and not completely drying up, at least not when protected by a layer
of varnish which the articles treated subsequently receive) dissolved in water. To
this bath is added a salt of nitric acid, acetic acid and gelatine (the latter can be
replaced by other glue or like substances). After the leaves have been in the bath
for a few minutes, they are smoothed say by hand.
(e) They are then dried, but only so far as impregnating liquid allows or sufficiently
to allow of varnishing and,
(provided with a coating of varnish. The varnish used should be colourless and
transparent and preferably flexible or elastic, such as varnish to which bees-wax
has been added.
Leaves having an especially large proportion of silicic acid (such as cycas leaves)
are preferably brushed during the operation mentioned under (b) in order to remove
the dissolved upper layer which comes off in flakes.
If the parts dyed in the bath are to be subsequently painted on one side or on both
or touched up (such as when natural or other spots are to be removed), this operation
can take place before, or simultaneously with the varnishing operation (f) in the
latter case the varnish is mixed with the colour to be used.
B. WITHOUT A DYE-BATH.
The process is exactly the same, only the bath mentioned under (d) receives no
dye, and painting and varnishing is effected just as described.
In dyeing and impregnating many details may be varied without departing from
the spirit of the invention which mainly consists in the use of sulphuric acid or other
acid or combination of acids having the same action.
Having now particularly described and ascertained the nature of the said invention
as communicated to me by my foreign correspondents and in what manner the same is
to be performed, I declare that what I claim is :-
1. The method of treating plants leaves and the like to give them a life-like
appearance, consisting in the application of diluted sulphuric or similarly acting acid,
.impregnating them with glycerine or equivalent hygrosophic body and dyeing in a
bath and varnishing, the leaves or parts being painted or not before or after
varnishing, substantially as described.
2. The method of treating plants leaves and the like so as to give them a life-like
appearance, consisting in the application of diluted sulphuric or similarly acting
acid washing dyeing in a bath, impregnated with glycerine, or equivalent, drying and
varnishing, substantially as described.
3. The method of treating plants leaves and the like so as to give them a life-like
appearance, consisting in the application of diluted sulphuric or similarly acting acid
washing in water, dyeing in a bath, impregnated with glycerine or equivalent,
drying and colouring on all sides or on one side or in parts and varnishing,
substantially as described.

page_text: 4. The method of treating leaves and the like so as to give them a life-like
appearance consisting in the application of diluted sulphuric or similarly acting acid
washing in water, impregnating with glycerine or equivalent, drying painting or
varnishing, substantially as described.
5. The method of treating plants leaves and the like so as to give them a life-like
appearance consisting in the application of diluted sulphuric or similarly acting acid,
washing in water, impregnating in a bath consisting of aniline dye dissolved in water,
glycerine or equivalent, a nitrate, acetic acid and gelatine or its equivalent, drying
and varnishing, and if desired colouring all or in parts before the varnishing operation,
substantially as described.