282 APPENDIX. 



moment vapor is seen to rise from the section it indicates the attachment of the section 

 to the cover-glass. 



4. Flood section on cover-glass or slide with xylol; this dissolves out the paraffin. 

 It is better to pour off the first xylol and drop on fresh xylol (one minute). 



5. Remove xylol with two applications of absolute alcohol (one minute). 



6. Treat specimen with two or three applications of 95% alcohol (one to two 

 minutes). 



7. Next wash in water (one to two minutes). 



8. Flood specimen with haemalum of Delafield's haematoxylin (three to seven 

 minutes). 



9. Wash in tap water for about two to five minutes until a purplish tinge is 

 developed in the section. The alkali in ordinary tap water develops this color. 



10. Apply i to 1000 eosin for thirty seconds to one minute. 



11. Wash in water; then in 95% alcohol; then in absolute alcohol. 



1 2. Apply a few drops of xylol and as soon as the section is perfectly transparent 

 mount in balsam. 



The staining by haematoxylin and eosin is the best for the study of the histology 

 of a section. It only requires about ten minutes to run a preparation through for 

 diagnosis by this method. 



The reagents are best kept in dropping-bottles. 



The staining of sections on slides is exactly as for those on cover-glasses. Cop- 

 lin's staining jars are very convenient for use in staining slides. 



Where the cover-glass method is used, staining by Gram's method, acid-fast stain- 

 ing, capsule staining, etc., may be carried out as for bacterial preparations. 



For staining Gram positive bacteria in sections, the Gram method as for bacterial 

 preparations, using dilute carbol fuchsin as a counter stain, gives good results. 



For Gram negative bacteria stain with thionin as for blood preparations (10 to 20 

 minutes). Then differentiate in i to 500 acetic acid solution for ten to twenty 

 seconds, wash with water, then with 95% alcohol, and quickly through absolute 

 alcohol and xylol. 



Nicolle's Method. i. Stain with Loffler's methylen blue ten to fifteen minutes. 



2. Differentiate in i to 500 acetic acid ten to twenty seconds. 



3. Place in i% solution of tannin for a few seconds (fixes color). 



4. Wash in water, then into 95% alcohol, absolute alcohol, xylol and balsam. 

 Van Giesen's Stain. Take of one percent aqueous solution acid fushsin from 



5 to 15 c.c. Saturated aqueous solution picric acid 100 c.c. The method of using 

 is to first stain with hsematoxylin in the usual way. Then pour on the picro-acid fuch- 

 sin solution and allow to stain for one to five minutes. Wash, pass through alcohols, 

 and xylol and mount in balsam. 



Connective-tissue fibres, axis cylinders and ganglion cells are stained a bright 

 garnet red. Myelin, muscle fibers and cells generally are stained yellow. Nuclear 

 staining is that of haematoxylin. The stronger stain is used for nerve tissue; the 

 weaker for demonstrating connective tissue in tumors. 



