PREPARING THE CELLS TO RECEIVE OBJECTS. 35 



flat, and clean crown-glass, free from specks) for the 

 slides ; and for the toppings, thin glass covers. The 

 cells are thus prepared : — A card, having marked on it, 

 in strong black lines, the outline of the intended cell, 

 is to be laid under the glass slide, to serve as a 

 guide in drawing the lines on the glass, with a ca- 

 mel's-hair brush dipped in black Japan varnish. The 

 brush should be very full of colour, to insure sufficient 

 depth in the walls of the cell. The outline being drawn, 

 the glass slide is to be laid aside, in a horizontal posi- 

 tion, for a few hours, until the varnish is dry enough to 

 permit the slide being placed edgeways without risk of 

 its running. It is desirable to have a good many slides 

 ready prepared, with cells of different sizes, and diffe- 

 rent depth of w 7 alls. 



When it is intended to mount a specimen, the best 

 and most interesting portion of the plant is selected, 

 and arranged carefully in the cell, which can only be 

 properly done under a good single magnifier ; the 

 ramuli being accurately separated and spread, and not 

 overlapping one another. Transverse and longitudinal 

 sections of the plant, and a portion showing the fruit, 

 &c, may also be placed in the same cell, properly dis- 

 played. 



A small quantity of the preserving fluid is then to 

 be taken out of the bottle, by means of an ivory or 



D 3 



