182 Modem Microscopy 



Pour off the alcohol and ether, and add a thin solution of 

 celloidin, and soak for two or three days ; then remove the 

 stopper of the bottle, and let the eelloidin evaporate to 

 about half its original bulk. Now remove a specimen from 

 the eelloidin, and hold it in a pair of forceps until the 

 eelloidin sets, then place it in methylated spirit and soak 

 for an hour or two to complete the hardening. The em- 

 bedded specimen may now be fastened to a cork with a 

 little eelloidin, and longitudinal sections made in a Cath- 

 cart microtome, or it can be placed between two pieces of 

 carrot, and the sections made with any ordinary well micro- 

 tome. The sections must then be dehydrated in methylated 

 spirit, cleared in oil of bergamot, and mounted in Canada 

 balsam; or, if desired, they may be soaked in water to 

 remove spirit, and be mounted in glycerine jelly. 



Fertile Branch of Chara. — Chara is usually very dirty ; 

 to clean it, wash well in repeated changes of water, then 

 in very dilute acetic acid for a few minutes only ; again 

 wash in water, and preserve in camphor water. 



Make a cell with shellac cement as directed above, place 

 a fertile branch of chara in it, and examine under a dissect- 

 ing microscope or lens ; with needles clear away the leaves 

 from the archegonia and antheridia, fill the cell with 

 camphor-water, and apply a cover-glass. 



When a deep cell is required for a specimen to be 

 mounted in acetate of copper, never use one made of any 

 metal. Vulcanite or glass cells must be used. To one side 

 of a cell apply a coat of shellac cement and let it dry ; now 

 take a slide and warm it over a spirit-lamp ; take up the 

 cell in a pair of forceps, and bring the cemented side in 

 contact with the centre of the warmed slide, and press it 

 down until it adheres firmly ; then add another coat of 

 cement to the upper side of the cell, and let it nearly dry, 

 put in the specimen, fill the cell with solution, and apply 

 the cover-glass. 



Prothallus of Fern. — Preserve in acetate of copper and 

 mount in the same fluid in a shallow cell. 



