KtJHNE'S AND ^VEIGERT'S METHODS 89 



differentiate them, and after clearing with an etherial oil and 

 removal of this with xylol, are put up in Canada balsam. 



In the fluoresceine and oil of cloves method the sections are 

 immersed for five to ten minutes in a concentrated aqueous 

 solution of oxaUc acid, which acts as a mordant, rinsed in 

 water, and dehydrated in alcohol. The staining which 

 follows is done with fuchsine in aniline water, or methyl 

 blue dissolved in ^ to 1 per cent, aqueous solution of 

 ammonium carbonate. To dehydrate, the sections are left 

 for five to ten minutes in absolute alcohol to which is added 

 a little fuchsine or methyl blue as the case may be, and 

 differentiation is effected with oil of cloves containing 

 fluoresceine. They are thereupon cleared in etherial oil, the 

 oil is extracted with xylol, and they are mounted in Canada 

 balsam. Sections stained in methyl blue are transferred 

 from the fluoresceine and oil of cloves to eosine and oil of 

 cloves before being brought into etherial oil. 



Klihne's dry method. — A one per cent, solution of ammo- 

 nium carbonate is mixed with a concentrated aqueous 

 solution of methyl blue, and this is allowed to act on the 

 sections for ten to fifteen minutes. They are then washed 

 in water, decolorised in an aqueous solution of hydrochloric 

 acid, again washed in water, dried upon slides, cleared in 

 xylol, and mounted in Canada balsam. 



Weigert's iodine method. — By Weigert's method the 

 sections are stained in aniline water gentian violet, rinsed 

 in a solution of common salt, laid upon slides, and dried, 

 and solution of iodine is dropped on them. After they 

 have been again dried, aniline oil is poured over them 

 and renewed several times. It is then removed with xylol, 

 and the sections are mounted in Canada balsam. 



A combination of Weigert's with Kiihne's violet method 

 (see p. 88) consists in staining the sections in a concen- 

 trated aqueous solution of violet to which some hydrochloric 



