12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I40 



Hansen's iron trioxyhematein. 



1. Steps I to 12, above. 



2. Hansen's hematein, 3 minutes. 



3. Wash in water, 10 minutes. 



4. Aqueous picrofuchsin (lo-percent acid fuchsin, aqueous: picric 



acid, saturated aqueous: distilled water {2-^:^^ -.yy) — no 

 longer than 10 seconds. 



5. Dehydrate rapidly, clear in xylol, and mount. 



Silver impregnation procedure (Bodian's, modified). 



Precautions: All glassware must he scrupulously clean. (Soak all 

 glassware overnight in detergent, rinse in distilled water just be- 

 fore use.) Use only chloride-free distilled water. (Drop small 

 crystal of AgNOs in sample of water. If precipitate forms, water 

 is unfit for use.) Use hone or plastic forceps only. (Avoid use 

 of any metal instruments or containers whatsoever.) 



1. Steps I to 12 above. 



2. Hydrate slides in at least four changes of distilled water for 



about ^ hour. 



3. Place slides in i.o-percent silver protein solution, prepared as 



follows : 



(a) Into 100 ml. of distilled water, place about 15 



grams of metallic copper, which has been thor- 

 oughly washed in 70-percent alcohol (10 

 changes) and in distilled water (12 changes) ; 

 and spread evenly on bottom of staining dish. 



(b) Sprinkle i gm, of "silver protein, strong, highest 



purity for Bodian staining" ^^ onto surface of 

 water. (Do not stir while powder is on surface ; 

 let it dissolve without agitation.) 



(c) Place slides gently into staining dish, cover and 



place in total darkness in incubator (37°C.) for 

 19 hours. 



4. Remove staining dish from incubator, wash slides quickly in 



distilled water, rubbing debris from slides with finger. 



5. Develop in the following reducing solution, made up fresh im- 



mediately before use, for 10 minutes: 



i<i Catalogue No. M 772 P- 



