CHAPTER XXIX. 355 



According to UNNA in Encycl. mik. Technik., 1910, ii, p. 411, 

 material should be fixed in chemically pure absolute alcohol and 

 sectioned in celloidin. Care should be taken to avoid contamination 

 of the liquids by tannin ; corks, and supports for imbedding, should 

 be soaked for some hours before use in 2 per cent, carbonate of 

 soda 



763. Mastzellen (NORDMANN, Beitr. s. Kenntniss d. Mastzellen, 

 Inaugural diss., Helmstedt, 1884.). A concentrated solution of vesuvin 

 containing 4 to 5 per cent, of hydrochloric acid. Stain for a few minutes, 

 and dehydrate with absolute alcohol. 



764. Plasma Cells, UNNA'S Later Methods (UNNA, in Encycl. mik. 

 TechniL, 1910, ii, p. 411). 



A. For -Large Plasma Cells. 



(1) Ten minutes in Griibler's polychrome methylen blue solution, 

 wash and drain. Fifteen minutes in 1 per cent, orcein solution 

 (Griibler), without acid ; absolute alcohol, so long as methylen blue 

 comes away abundantly ; bergamot oil, balsam. 



(2) Methylen blue as above, two minutes. Wash well. Then 

 two minutes in glycerin-ether mixture* (Griibler) diluted with 

 4 volumes of water. Wash thoroughly (two to five minutes) ; 

 absolute alcohol, bergamot oil, balsam. 



(3) Modification of a method of PAPPENHEIM (V if chow's' Arch., 

 clxiv, 1901, p. 111). Ten minutes in the warm, 20 to 40 C., in 

 Griibler's carbol-pyronin-methyl-green mixture. Cool rapidly, by 

 plunging the recipient containing the tissues into cold water. Remove 

 the tissues with a platinum wire and rinse. Absolute alcohol, 

 bergamot oil, balsam. 



STROPENI (Zeit. wiss. Mik., xxix, 1913, p. 302) takes acridin red 

 instead of the pyronin. This will work after various fixatives. 



B. For Small Plasma Cells. 



(4) As No. 2. supra, but only half a minute in the glycerin-ether. 



(5) After removal of the celloidin from the sections with alcohol 

 and ether, five minutes in polychrome methylen bine, wash, dry 

 with blotting-paper, dehydrate (about a minute) in a mixture of 

 2 parts alcohol to 3 of xylol, then one minute in xylol ; then five 

 to ten minutes in alum-anilin (prepared by allowing anilin to stand 



* Glycerin ether C 6 H 10 3 , is a glycerin anhydride. It is a differen- 

 tiating agent for basic dyes. The glycerin-ether mixture in question 

 contains alcohol and glycerin, and can be obtained from Griibler. 



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