The Venetian Turpentine Method 101 



half the bulk of a grain of wheat in 30 c.c. of 90 per cent alcohol, 

 will give an efficient solution. The time required for successful 

 staining will vary from 3 to 30 minutes. Do not put all the material 

 into the anilin blue at once, but, by trying a few filaments at a time, 

 find out what the probable periods may be. 



4. Rinse off the stain in 90 per cent alcohol, and then treat for a 

 few seconds in acid alcohol (1 very small drop of HC1 to 30 c.c. of 90 

 per cent alcohol). The acid alcohol fixes and brightens the anilin 

 blue, but extracts the Magdala red. If the anilin blue or the acid 

 alcohol acts for too short a time, the blue will be weak; if they act 

 too long, the red is lost entirely. If the blue overstains too much, 

 wash it out in 95 per cent alcohol. If the red overstains, wait until 

 the mount is finished, and then reduce the red by exposing the slide 

 to direct sunlight. 



5. Absolute alcohol, 5 or 6 seconds. 



6. Transfer quickly to 10 per cent Venetian turpentine and pro- 

 ceed as in the previous schedule. 



The surprising beauty of successful preparations will compen- 

 sate for whatever failures may occur. Nuclei and pyrenoids should 

 show a brilliant red, while the chromatophores and cytoplasm should 

 be dark blue. The cell walls should show a faint bluish color. 



Haidenhain's Iron-Alum Haematoxylin and Eosin. Follow 

 the schedule for iron-haematoxylin until the glycerin has been washed 

 out in 95 per cent alcohol. Then stain for a minute in a solution of 

 eosin in 95 per cent alcohol. Wash for a minute in 95 per cent alcohol, 

 then a minute in absolute alcohol, and then transfer to the 10 per cent 

 Venetian turpentine. 



Other Stains may be used. Aqueous stains should be used before 

 starting with the 10 per cent glycerin. Alcoholic stains should be in 

 strong alcohol about 90 per cent and should be applied just after 

 washing out the glycerin. 



This method is equally good for filamentous fungi and also for 

 the prothallia of Equisetum and ferns, for delicate liverworts and 

 mosses, and similar objects. 



