232 TAGG—NOTES ON MUSEUM-METHODS 
2. The direct and immediate exposure of the jar con- 
taining the specimen to sunlight. 
The employment of clean spirit only. 
Oo 
B. BLEACHING BEFORE PRESERVING. 
I. PRELIMINARY AND RAPID KILLING 
The darkening in alcohol of many specimens is prevented if 
they are first immersed in some rapidly acting killing agent. 
The most important of these are boiling water, ee alcohol, 
and boiling acetic acid and alcohol. 
a. Boiling Water. 
The specimen is immersed in hot or even boiling water for 
from I to 5 minutes, or even, in the case of fleshy or solid speci- 
mens, for much longer. The length of time of immersion should 
vary with the character and consistency of the specimen. Sub- 
sequently the specimen is placed in alcohol and exposed to the 
action of sunlight. 
The specimens become soft and flaccid during the process and 
harden subsequently in the alcohol. In the case of flowers the 
sap may aggregate below the epidermis in the form of blisters. 
6. Bowling Alcohol go per cent. 
This is employed in the same way as boiling water. The 
specimens are immersed for a varying time and are then 
transferred to normal 90 per cent. alcohol. Boiling alcohol 
penetrates more rapidly than does boiling water, but is not so 
effective, however, where much tannin is present, and, as with 
boiling water, blisters may form under the epidermis. 
¢. Boiling Acetic Actd and Alcohol. 
Acetic acid, . : 10 C.c. 
Alcohol 90 per one : gO C.c. 
This penetrates rapidly. The macerating action is somewhat 
considerable if the treatment is other than momentary. Blisters — 
may be produced as in the preceding ‘cases. The bleaching 
which results is usually perfect. 
