684 REPORT-—1896. 
Preservation of Plants for Exhibition Interim Report of the Com- 
mittee, consisting of Dr. D. H. Scorr (Chairman), Professor 
J. BayLtey Batrour, Professor L. Errera, Mr. W. GARDINER, 
Professor J. R. GREEN, Professor J. W. H. Trait, Professor 
F. E. WEtss, and Professor J. B. Farmer (Secretary), appointed 
to Report on the best Methods of Preserving Vegetable Specimens 
for Exhibition in Museums. 
APPENDIX PAGE 
I.—Report on Experiments made at the Institut Botanique de Université de 
Bruxelles. By Professor ERRERA . . - : 5 - 686 
Il.— Report by Prof. J. W. H. TRAIL, WA, ERS. . : ; . + G92 
THE Committee are not yet in a position to present a definitive report ; in 
the meantime they desire to place on record the results obtained by in- 
dividual members of the Committee and others, as their experience may 
be of immediate service to those interested in this subject. 
Mr. W. Gardiner points out that in his opinion the processes of 
(1) killing, and (2) fixing and mounting, have not been kept sufficiently 
distinct. The killing of the protoplasm should be as rapid as possible, so 
as to avoid active plasmolysis. He suggests (1) hot glacial acetic acid, 
owing to its power of rapid penetration ; (2) superheated steam ; (3) strong 
alcohol. If a rapidly acting substance cannot be used, a poisonous solu- 
tion, possessing as nearly as possible the same osmotie equivalent as the 
cell-sap, should be employed. After the tissues have been killed they may 
be preserved in any suitable liquids, e.g. 70 per cent. spirit, or solution of 
formic aldehyde. 
Professor Farmer has made a number of experiments with formic 
aldehyde. He agrees with Mr. Gardiner as to the advisability of a 
preliminary and rapid killing, and finds that green parts of plants im- 
mersed in strong alcohol for a short time, then transferred to strong 
solutions of copper acetate, and finally preserved in formic aldehyde, gave 
better results than when the preliminary killing in spirit was omitted. 
For most plants experimented on, he finds that strong solutions (15-30 per 
cent. of the commercial ‘ formaline’) in weak (15-20 per cent.) spirit give 
better results than weaker solutions. In all cases the specimens were . 
greatly improved by the treatment with copper acetate or sulphate (see 
Professor Trail’s report, Appendix II.). Without this, the green colour 
had, with but few exceptions, failed after immersion in the formic aldehyde 
for four months, although they had in some cases shown no change until 
three months had elapsed. 
Mr. J. R. Jackson, of the Royal Gardens, Kew, finds that a saturated 
solution of salt, boiled to expel air, and carefully stoppered, is useful for 
many fleshy fruits, some of which, e.g. apples, retain their colour very 
well under this treatment. He finds Goadby’s solution, formerly so much 
employed, unsatisfactory, and considers methylated spirit, on the whole, 
the best of the liquids in common use. Formic aldehyde has been tried on 
a number of plants, with good results in some cases, especially with those 
fruits with red or reddish tints and firm flesh, 
In drying large specimens of succulent plants or fruits, it is important 
that the process should not be hurried, or cracking and warping may 
ensue. 
