Dry Mounts 221 



LESSON XIII. 

 DRY MOUNTS. 



Opaque Cells. — Place a slide in a turn-table, and run 

 a disc of black varnish on its centre; allow this to dry. 

 Take a piece of black paper and punch out a disc of the 

 same size as the one on the slide, and gum it on to the 

 varnish spot. Take a cell, either, metal or vulcanite, of 

 the required depth and fasten it to the paper disc with 

 gold size, or black shellac cement, and put the slide away 

 until quite dry. Now place a very small quantity of gum 

 on the centre of the paper disc, and put the specimen into 

 it ; but take care that the gum does not extend beyond the 

 object, or the appearance of the mount will be spoiled. 

 When the gum has dried, put the slide into the turn-table 

 again, and: run a ring of any good cement on the upper 

 surface of the cell, and when this has become about half 

 dry apply a cover-glass, which must be pressed down with 

 a needle-point until it adheres firmly to the cement all 

 round the cell. Put the slide aside for an hour or two, and 

 then run on a good coat of black shellac cement. 



Feathers of humming-birds, eggs of butterflies and 

 moths, small microscopic seeds, gills of many fishes, skins 

 of fishes, skins of snakes, and transverse or longitudinal 

 sections of stems of plants, are all mounted as opaque 

 objects in the same manner as above. The former should 

 be arranged in the cell in a group. The gills, skins, etc., 

 should be well washed with distilled water and dried under 

 pressure between two glass slips tied together with twine. 



Transparent Cells. — Take a cell of the desired depth 

 and apply a coat of cement to one side of it, and allow it 

 to become very nearly dry. Take a slide and warm it 

 gently over a spirit-lamp ; take up the cell with a pair of 

 forceps and place it on the centre of the slide, the warmth 

 of which should cause the cement of the cell to melt; if 

 not, warm a little more, and press the cell down gently 



