I 64 BACTERIOLOGY. 



Take out the cover-glass, and transfer it for a few seconds to 

 acidulated alcohol (two drops of nitric acid in a watch-glass 

 full of alcohol). Wash in distilled water, dry, and preserve 

 in balsam. After-stain, if necessary, with bismarck- 

 brown, or methylene-blue. 



Weigert-Ehrlich method (vide p. 58). 



Orttis modification of Ehrliclis method. Stain by the 

 method of Ehrlich, but decolorise with acidulated alcohol 

 (one of hydrochloric to one hundred parts of 70 per cent, 

 alcohol). 



Gibbes method* Stain cover-glass-preparations in ma- 

 genta solution (No. 22) for 15 20 minutes. Wash in 

 (i 3) solution of nitric acid, until the colour is removed. 

 Rinse in distilled water. After-stain with methylene- 

 blue, methyl-green, iodine-green, or watery solution of 

 crysoidin, five minutes. Wash in distilled water till no 

 more colour comes away. Transfer to absolute alcohol 

 for five minutes ; dry, and preserve in Canada balsam. 

 Leave sections in the stain for half an hour, then treat 

 with nitric acid, and wash with distilled water. Transfer 

 to methylene-blue till deeply stained, wash again in 

 distilled water, and then in spirit. Pass through absolute 

 alcohol and clove-oil, and preserve in Canada balsam. 



Gibbes' new method. Cover-glass-preparations are placed 

 in the double staining solution (No. 16), which has been 

 warmed in a test-tube, and, as soon as steam rises, poured 

 into a watch-glass. They are allowed to remain for five 

 minutes, and then are washed in methylated spirit till no 

 more colour comes away, dried in the air or over a spirit- 

 lamp, and mounted in Canada balsam. If the solution is 

 used without warming, the cover-glasses must be left in it 

 for an hour. Sections are treated on the same principles, 

 but must be left in the solution for several hours. The 

 crumpling of the sections by the action of nitric acid is 

 avoided, 



* Gibbes, Practical Pathology. 1883. 



