STAINS AND STAINING 
51 
Mayer’s Haem-Alum. — Haematoxylin, 1 g., dissolved with gentle 
heat in 50 c.c. of 95 per cent alcohol and added to a solution of 50 g. 
of alum in a liter of distilled water. Allow the mixture to cool and 
settle; filter; add a crystal of thymol to preserve from mold (Lee). 
It is ready for use as soon as made up. Unless attacked by mold, 
it keeps indefinitely. Transfer to the stain from water. It is seldom 
necessary to stain for more than 10 minutes, and 4 or 5 minutes 
is generally long enough. As a rule, better results are secured by 
diluting the stain (about 1 c.c. to 10 c.c. of distilled water) and 
allowing it to act for 10 hours or over night. 
This is a good stain for the nuclei of filamentous algae and fungi, 
since it has little or no effect upon cell walls or plastids. Wash 
thoroughly in water, transfer to 10 per cent glycerin, and follow the 
Venetian turpentine method, as described in chapter viii. 
Erlich’s Haematoxylin.— 
Distilled water. 50 c.c. 
Absolute alcohol. 50 c.c. 
Glycerin. 50 c.c. 
Glacial acetic acid. 5c.c. 
Haematoxylin. 1 g. 
Alum in excess. 
Keep it in a dark place until the color becomes a deep red. If 
well stoppered, it will keep indefinitely. Transfer to the stain from 
50 per cent or 35 per cent alcohol. Stain 5 to 30 minutes. Since 
there is no danger from precipitates and the solution does not over¬ 
stain, it is not necessary to treat with water or with acid alcohol, but 
the slide may be transferred from the stain to 70 per cent alcohol. 
Eosin, erythrosin, or orange G are good contrast stains. Jeffrey 
uses safranin and Erlich’s haematoxylin for woody tissues. 
Boehmer’s Haematoxylin.— 
^ ( Haematoxylin. 1 g. 
\ Absolute alcohol. 12 c.c. 
/ Alum. 1 g. 
1 Distilled water. 240 c.c. 
The solution A must ripen for two months. When wanted for 
use, add about 10 drops of A to 10 c.c. of B. Stain 10 to 20 minutes. 
Wash in water and proceed as usual. 
