FREEHAND SECTIONS 
85 
While the material is still fresh and moist, cut the sections and 
place them at once in 95 per cent alcohol, where they should remain 
20 to 30 minutes. It is not necessary to use a large quantity of 
alcohol; 10 c.c. is enough for 100 thin sections of the rhizome. 
Pour off the alcohol and pour on an alcoholic solution of safranin 
(a 1 per cent solution of safranin in 50 per cent alcohol. See chapter 
xxix on “Formulas for Reagents”). It is better to let the safranin 
act over night, or even for 24 hours. 
Pour off the safranin (which may be used repeatedly) and pour 
on 50 per cent alcohol. The alcohol will gradually wash out the 
safranin, but this stain is washed out more rapidly from cellulose 
walls than from those which are lignified. The sections should 
remain in the alcohol until the stain is nearly—but not quite—washed 
out from the cellulose walls, while still showing a brilliant red in the 
large lignified tracheids. If 5 or 10 minutes in the alcohol draws the 
safranin from the lignified walls as well as the cellulose, stain longer; 
if the differentiation is not secured in 5 or 10 minutes, a small drop of 
hydrochloric acid added to the alcohol will hasten the process. 
Some recommend staining for only 1 or 2 hours, but the washing-out 
process is likely to be rapid and uncertain. 
Pour off the alcohol and wash the sections thoroughly in ordinary 
drinking-water. The washing should be particularly thorough if 
acid has been used to hasten the previous process, for the preparations 
will fade if any acid remains. 
Stain in Delafield’s haematoxylin 3 to 30 minutes. Usually 5 
minutes will be about right. Delafield’s haematoxylin will stain the 
cellulose walls, but will have little or no effect upon lignified structures. 
Transfer to drinking-water, not distilled water. The red color 
of the whole section, as it appears to the naked eye, will be rapidly 
replaced by a rich purple. Continue to wash in water for 2 or 3 
minutes after the purple color appears. If the cellulose walls show 
only a faint purplish color, put the sections back into the stain and 
try a longer period. If the color is a deep purple or nearly black, 
add a little hydrochloric acid (1 drop to 50 c.c. is enough) to the 
water. It is better to put the drop into a bottle of water and shake 
thoroughly before letting the acidified water act upon the sections. 
As soon as the sections begin to appear reddish, which may be 
within 4 or 5 seconds, pour off the acidified water and wash in drinking- 
water, changing the water 3 or 4 times a minute, until the reddish 
