234 TAGG—NOTES ON MUSEUM-METHODS 
2.—Methods which render the specimen flaccid. 
Dilute Acid Alcohol. 
Alcohol go per cent., . ; . 40 C.C. 
ater, . : : : : : SOL x. 
Hydrochloric acid or Nitric acid, . 10 C.c. 
The addition of water to the acid alcohol, while rendering the 
specimen soft, prevents to a great extent any subsequent 
browning of the specimen when transferred to 90 per cent. non- 
acid alcohol for final exhibition. 
The specimen is either first immersed in 90 per cent. alcohol 
for a few minutes to wet the surface and then transferred to the 
dilute acid alcohol, or the fresh specimen is placed at once in 
the diluted solution. As in other cases, sunlight favours the 
bleaching. The macerating action is considerable, and the 
method should not be employed for delicate specimens. Where 
the specimens are less fragile and where boiling may be 
undesirable the results are usually good. Such a solution with 
nitric acid has been used with excellent results in the case of 
Musa, specimens of which, owing to the large quantities of 
tannin present in the tissues, are bleached with difficulty. 
C. BLEACHING AFTER PRESERVING. 
Specimens which have darkened under the action of the 
preservative fall into two groups :—First, those we wish to 
keep hardened in alcohol; second, those which permit a trans- — 
ference to an aqueous medium, softening not being a disadvan- 
tage. The methods available in the former case are not so effective 
as those available in the latter. 
1.—Methods which do not render the specimen flaccid. 
For these the acid alcohol solution already described is, 
invariably used. The specimen is transferred to the acid alcohol 
and the jar exposed to sunlight. The bleaching is sometimes 
slow, is not always effective, and never so good as when the fresh 
specimen is placed at once in the acid alcohol before discoloura- 
tion has taken place. 
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