Ii2 



§ 104. Mounting in glycerin media, (a) Pure glycerin ; 

 (^) glycerin and acetic acid, i %; (c) glycerin, alum carmine and 

 eosin (§ 156). 



Glycerin and glycerin-jelly are most serviceable in mounting 

 isolation preparations. For both of these mounting media the ob- 

 ject must be mounted from water or an aqueous solution. 



Arrange the section or teased tissue in the center of the slide, 

 drain off the water or aqueous solution in which the preparation is 

 and add a small drop of glycerin. Take a clean cover in the forceps, 

 breathe on the under side and carefully lower it upon the object ; 

 gently press it down. It is best to u.se only a small drop of glycerin 

 so as not to get it outside the cover, as it is hard to clean away sat- 

 isfactorih-. Clean carefully and seal with shellac in accordance 

 with § III. 



§ 105. Mounting in glycerin-jelly. The preparation should 

 be mounted from some aqueous solution. Warm the slide gently 

 and put it upon the centering card ; in the center of the slide place 

 a drop of warmed (melted) glycerin-jelly. Remove the object from 

 the water or aqueous solution and arrange it in the glycerin-jelly. 

 Grasp a cover-glass with the fine forceps, breathe on the lower side, 

 gradually lower it upon the object and gently press it down. Allow 

 the glycerin-jelly to set, keeping the slide horizontal meanwhile. 

 Scrape away the superfluous glycerin-jelly around the cover-glass 

 and seal with shellac (§ iii). 



§ 106. Preparation of shellac mounting cells. Place the 

 slide upon the turn table and center it (i. e., get the center of the 

 slide over the center of the turn table). Select a guide ring on the 

 turn table which is a little smaller than the cover-glass to be used ; 

 take the brush from the shellac, being sure that there is not enough 

 cement adhering to it to drop. Whirl the turn table and hold the 

 brush lightly on the slide just over the guide ring selected. An 

 even ring of the cement should result. If it is uneven, the cement 

 is too thick or too thin or too much, was on the brush. After a ring 

 is thus prepared, remove the slide and allow the cement to dry 

 spontaneously, or heat the slide in some way. Before the slide is 

 used for mounting, the cement should be so dry when it is cold 

 that it does not dent when the finger nail is applied. A cell of con- 

 siderable depth may be made with shellac by adding successive laj'- 

 ers as the previous one dries. 



