256 



MOUNTING IN GL ) CERIN JELL Y 



\CH. IX 



6. The slide is labeled. 



7. The preparation is cataloged and safely stored. 



(J 351.- Sealing the Cover- Glass when no Cell is used. — (A) For glycerin 

 mounted specimens. The superfluous glycerin is wiped away as carefully as 

 possible with a moist cloth, then four minute drops of cement are placed at 

 the edge of the cover (Fig. 200), and allowed to harden for half an hour or 

 more. These will anchor the cover-glass, then the preparation may be put on 

 the turn-table and ringed with cement while whirling the turn-table. 



c 



Fig. 202. A — Simple form of moist chamber made with a plate and bowl. 

 B, bowl serving as a bell jar; P, plate containing the water and over which the 

 bowl is inverted ; S, slides on which are mounted preparations which are to be 

 kept moist. These slides are seen endwise and rest upon a bench made by 

 cementing short pieces of large glass tubing to a strip of glass of the desired 

 length and width. 



B — Two cover-glasses (C) made eccentric, so that they may be more easily 

 separated by grasping the projecting edge. 



C — Slide (S) with projecting cover-glass (C). The projection of the cover 

 enables one to grasp and raise it without danger of moving it on the slide and 

 thus folding the substance tinder the cover. (From Proc. Amer. Micr. Soc, 

 1891). 



(B) For objects in glycerin jelly, Farrants' solution or a resinous 

 medium. The mounting medium is first allowed to harden, then the superfluous 

 medium is scraped away as much as possible with a knife, and then removed 

 with a cloth moistened with water for the glycerin jelly and Farrants' solution 

 or with alcohol, chloroform or turpentine, etc., if a resinous medium is used. 

 Then the slide is put on a turn-table and a ring of the shellac cement added. 

 (C) Balsam preparations may be sealed with shellac as soon as they are pre- 

 pared, but it is better to allow them to dry for a few days. One should never 

 use a cement for sealing preparations in balsam or other resinous media if the 

 solvent of the cement is also a solvent of the balsam, etc. Otherwise the 

 cement will soften the balsam and finally run in and mix with it, and partly 

 or wholly ruin the preparation. Shellac is an excellent cement for sealing 

 balsam preparations, as it never runs in. Balsam preparations are rarely sealed. 



