98 STAINING METHODS 



begins to form scrape and break up occasionally. 

 (On no account must the paste be allowed to fuse.) 



3. Grind the resulting mass into an amorphous 

 powder. 



4. Weigh out: 



Amorphous powder 0.5 grammes 



Dissolve in 



Methylic alcohol (Merck's puriss. for analysis) . 100 c.c. 



Allow time for true solution. (About three days is 

 sufficient.) 



METHOD. 



1 . Prepare film, dry, but do not fix. 



2. Flood the unfixed film with the stain, allow it to 

 act for 3 minutes (the methylic alcohol of the stain 

 fixes the film) . 



3 . Pour off the stain and wash in distilled water until 

 the film presents a pink colour. 



4. Dry and mount. 



Irishman's Stain. 



A. Weigh out: 



Methylene blue (medicinal) . . . i gramme 

 Dissolve in 



Sodium carbonate, o. 5 per cent, aqueous solution . . 100 c.c. 



Keep at 65 C. for 12 hours in either a hot incubator 

 or a water-bath; then stand in dark place at room 

 temperature (20 C.) for ten days. 



B. Weigh out : 



Eosin, extra B. A o.i gramme 



Dissolve in 



Distilled water 100 c.c. 



i. Mix the two solutions A and B in equal volumes, 



