f 
28 MIDLAND NATURALIST 
‘ 
It is well known that saffranine, like many of the so-called 
aniline dyes, is intensified in the presence of alkalies, and weakened 
_ or entirely removed in the presence of acids. Advantage is made 
cloudiness and muddiness is removed by washing for a second or 
more as is found necessary, in dilute hydrochloric acid. 
When the proper reduction of the color has been obtained the 
acid is rapidly removed by washing in water, and the slide may 
immediately be stained with saffranine, which need not be allowed 
stained the excess of red color may be taken out by washing 
with 95 per cent alcohol to which a small amount of slaked lime 
has been is alkali is but very slightly soluble in 
cellulose remain blue or purple-blue with the haematoxylin. 
If the red does not come out as quickly as desired, alcohol without 
any alkali may be used in washing. 
The preparation of microscopic slides by the process described 
is so rapid that the slides may be made by the dozen at a time, in a 
w minutes, and the preparation of a single slide does not take 
aboratory of Botanical Histology 
University of Notre Dame 
P * About 3 milligrams or calci ium hydroxide of slaked lime has, ex- 
periment been found to dissolve in 100 cc. of absolute alcohol, or le than 
1 gram in 30,000 pite. Dy et ot = IS SOM. 
however, in on he ge amount ater t, but i 
oe reet i St to etl vi general w presen in 
