230 TAGG—NOTES ON MUSEUM-METHODS 
preservation of dissections which shall show the more minute 
structural features of flowers. 
To prevent somewhat the adhering of the sand particles to the 
surface of the flower, the stirring of the sand with wax, such as 
a paraffin candle, so that each grain of sand comes to be covered 
with a thin coating of paraffin, has been recommended.’ 
BLEACHING. 
I. General. 
The methods following apply particularly to material preserved 
in alcohol ; they may be employed, however, with more or less 
success for specimens preserved in other media. 
The subject for convenience will be considered under the 
following heads :— 
A. Bleaching in go per cent. alcohol. The preservative in the 
case of material intended for alcohol is also the bleaching 
medium. 
B. Bleaching treatment, before preserving, of material known 
to blacken in alcohol. 
Cc. Bleaching of specimens already preserved, which have 
darkened under the action of the preservative. 
Treatment of the specimens before preserving and likewise 
treatment after preserving are to be avoided when the simple 
treatment by alcohol alone can be made to give sufficiently 
good results. 
The reasons for this are—first, treatment other than by alcohol 
alone has in a greater or less degree a softening and macerating 
action on the material bleached ; and, second, such treatment 
tends, with an exception in the case of acid alcohol, to render the 
specimen flaccid. When special bleaching is, however, resorted 
to, better results are, as a rule, to be obtained by treating the 
specimens before preservation than can be secured by treatment 
subsequently of material already discoloured. 
hen it is known or supposed that a specimen will 
bleach in alcohol no special treatment is accorded it; if the 
1 Bailey, Rule-book, p. 187. 
