Finishing of Slides 223 



slide with a clean cloth, and apply a coat of any good 

 cement. 



Glycerine Jelly. — Put the slide into a saucer of cold 

 water and allow it to soak for a few minutes, then take a 

 penknife and carefully scrape away the jelly from the edge 

 of the cover. Give the slide a good wash in water, and 

 place it in some methylated spirit, which will remove the 

 water. Dry with a clean soft cloth, and apply a coat of 

 black shellac enamel, and when this has dried add another. 



Farrant's Medium. — Allow the slide to dry for a few 

 days, then put it into a saucer of water and wash away the 

 excess of medium with a soft brush. Drain off as much 

 water as possible, and, if the cover is firm enough, dry the 

 slide carefully with a soft cloth ; if not, allow all the 

 moisture to evaporate by exposure to the air. When quite 

 dry, put it in a turn-table and apply a coat of cement, and 

 when this has dried add another. 



Dry Mounts do not require any washing, but they should 

 have one or two coats of any good cement. 



Asphalte and white zinc cement may be used when 

 desired for balsam or dry mounts, but they are both use- 

 less for any of the aqueous or fluid media. 



A really good black enamel may be made in the follow- 

 ing way : 



Dissolve best black sealing-wax in methylated spirit until 

 the solution is as thick as treacle, then mix this with an 

 equal quantity of marine glue ; then, if too thick, dilute 

 with a little methylated spirit. This cement has been 

 alluded to all through the lessons as shellac cement, and it 

 is the best I know of for general purposes. The black 

 enamel should be kept in a wide- mouthed, stoppered bottle. 

 Should the stopper become fixed, just warm the neck of 

 the bottle over a spirit-lamp, it can then be easily removed. 



When a ring is being applied to a slide, the turn-table 

 should not be run too fast, and the extreme point of the 

 brush should only just touch the glass. A thin coat must 

 be run on at first, then give it about ten minutes to dry. 



