CH. 1X~\ MOUNTING IN GL YCERIN 255 



In all of these different methods, unless glycerin of increasing strengths 

 has been used to prepare the tissue, the fixing agent is washed away with 

 water before the object is finally and permanently mounted in either of the 

 media. 



For glycerin jelly no cell is necessary unless the object has a considerable 

 thickness. 



\ 349. Order of Procedure in Mounting Objects in Glycerin. 



1. A cell must be prepared on the slide if the object is of considerable 

 thickness (§ 346). 



2. A suitably prepared object is placed on the center of a clean slide, and 

 if no cell is required a centering card is used to facilitate the centering 

 (Fig. 199). 



3. A drop of pure glycerin is poured upon the object, or if a cell is used, 

 enough to fill the cell and a little more. 



4. In putting on the cover-glass it is grasped with fine forceps and the 

 under side breathed on to slightly moisten it so that the glycerin will adhere, 

 then one edge of the cover is put on the cell or slide and the cover gradually 

 lowered upon the object (Fig. 197). The cover is then gently pressed down. 

 If a cell is used, a fresh coat of cement is added before mounting. 



-•(~X3 



Fig. 200. Slide and cover-glass showing method 

 of anchoring a cover-glass with a glycerin prepara- 

 tion when no cell is used. A cover-glass so anchored 

 is not liable to move when the cover is being sealed 

 (« 35')- 



Fig. 201. Glass slide with cover-glass, a drop of 

 reagent and a bit of absorbent paper to show method 

 of irrigation. 



5. The cover-glass is sealed. 



6. The slide is labeled. 



7. The preparation is cataloged and safely stored. 



g 350. Order of Procedure in Mounting Objects in Glycerin Jelly. 



1. Unless the object is quite thick no cell is necessary with glycerin jelly. 



2. A slide is gently warmed and placed on the centering card (Fig. 199) 

 and a drop of warmed glycerin jelly is put on its center. The suitably pre- 

 pared object is then arranged in the center of the slide. 



3. A drop of the warm glycerin jelly is then put on the object, or if a cell 

 is used it is filled with the medium. 



4. The cover-glass is grasped with fine forceps, the lower side breathed on 

 and then gradually lowered upon the object (Fig. 197) and gently pressed 

 down. 



5. After mounting, the preparation is left flat in some cool place till the 

 glycerin jelly sets, then the superfluous amount is scraped and wiped away 

 and the cover-glass sealed with shellac {\ 347). 



