SECTION TWO 



B. Acid fuchsin 25% aqueous. 



C. Picric acid, saturated, alcoholic 15 ml. 

 Distilled water . . . . . . 30 ml. 



D. Light green 10% aqueous. 

 Technique: 



1. Fix thin slices of the material in 10% formalin for twenty- 

 four hours to three days. 



2. Wash for twenty-four hours in running water. 



3. Immerse very thin slices of the material in a comparatively 

 large volume of Solution A which should be changed once or twice 

 if it blackens. 



4. Wash for several hours in running water. 



5. Pass through ascending grades of alcohol. 



6. Clear in the usual manner and embed in paraffin wax. 



7. Sections not more than 2 to 4/^ in thickness are fixed to 

 slides. 



8. De-wax with xylol. 



9. Rinse thoroughly with absolute alcohol and pass through the 

 usual descending grades of alcohol down to distilled water. 



10. Stain for an hour at 60° C. with the acid fuchsin solution. 



11. Allow the preparation to cool to room temperature; then 

 wash with water. 



12. Immerse in Solution C (picric acid) from one second to two 

 minutes. 



13. Rinse in two changes of water. 



14. Stain from one half to one hour in the Light Green 

 solution. 



15. Rinse quickly in absolute alcohol. 



16. Rinse in xylol. 



17. Mount in Canada balsam or Cristalite. 



Results: 



Migrating astrocytes, of varying shades of green and sometimes 

 containing fuchsinophile granules of brown stained lipoid inclu- 

 sions. Lipoid contents of perivascular phagocytes are brown to 



139 



