SECTION TWO 



3. Transfer to Solution A for 3 to 6 days at 37° C. in the dark, 

 changing the solution every twenty-four hours. 



4. Wash in distilled water; then immerse in Solution B for 

 twenty-four to seventy-two hours in the darkroom at room tem- 

 perature. 



5. Wash in distilled water; then dehydrate with 80%, 95%, 

 and absolute, alcohol. 



6. Clear in cedarwood oil and embed in parafHn wax. 



7. Sections are cut 5/1 in thickness and mounted after removal 

 of the paraffin wax. 



Results: 



Treponema: jet black. Tissue: yellow to brown. 



References : 



Conn, H. J. & Darrow, M. A. (194?), Pt- 3, sect. B, p. 14. 

 Levaditi, C. & Manouelian (1906). 

 Mallory, F. B. (1938), p. 293. 



LIGHT GREEN - ACID FUCHSIN 



(After Alzheimer) 



For demonstrating neuroglia changes 



Solutions required: 



A. Osmic acid 2% aqueous 

 Chromic acid 1% aqueous 

 Glacial acetic acid 



B. Acid fuchsin 25% aqueous. 



C. Picric acid, saturated, alcoholic 

 Distilled water 



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. 



263 



