72 Mr. English on Preservation of Plants.
paper; press in the usual way, shifting if necessary until
dry. Before mounting, place the specimens between papers
on a board, and "iron" with a moderately warm laundry
iron to drive off the superfluous petroleum. Keep under-
pressure until cool, and then mount for the herbarium in
the usual way.
2nd.—In endeavouring to preserve colours, some strange
anomalies are observed. Two flowers from different
species, but apparently identical in colour, do not show the
same result. This is a point most deserving of attention.
The yellow and purple Pansies I exhibit were dried in the
press, "ironed" with a warm iron, immersed in petroleum,
pressed and "ironed" again. On the other hand, the
specimens of Crocus were immersed at once in the petro-
leum. The difference in the results is very noticeable.
Of course time alone can test the permanency of the
colours ; but should any of our members think the process
worth a trial, I shall be very pleased to hear from them,
and exchange ideas on the subject.
J. E.
April 24th, 1880.
II.
(Read September 25th, 1880.)
At the April meeting I introduced the subject of preserving
plants with their natural colours by using petroleum. I
soon found it to be a question whether petroleum alone
gave sufficient residue on evaporation to effect the purpose
in view. I tried various methods to remedy this defect, by
adding gum resins, solid paraffin, and other substances,
but with no good result. It would be useless to enumerate
the failures I have experienced since I took the subject in
hand. I worked on smoothly for some time, until new
flowers came into blossom, such as Galium, Melampyrum.
These plants, in drying, became quite black, and I was
obliged to make further trials.