478 PREPARATION, MOUNTING. AND COLLECTION OF OBJECTS 



instrument, but prefers a smooth glass rod or tube ; the section in 

 fluid can easily be made to wrap itself round the rod, from which it 

 may be rolled off into a drop of liquid placed on the slide. It must 

 be manifest that the less we have to manipulate such delicate sections 

 as we are now considering, the better ; to get a section on and off 

 the ' lifter ' is a needless" process. We should, as stated above, 

 mount on the cover-glass, and this cover should be the only lifter 

 employed. 



The cover must be carefully cleaned, and properly selected as to 

 size and tenuity. By means of a needle or the handle of an ivory 

 dissecting-knife the clearing fluid in which the section is resting 

 prior to mounting is gently disturbed, in a good-sized vessel or 

 saucer, until the section desired is in its proper position on the 

 cover. Now lay the cover, section upwards, on fresh blotting-paper, 

 to take off the superfluous liquid from the free side of the cover, and 

 then hold the edge of the slip at an angle, more or less acute, with 

 the section towards the blotting-paper, But never suffering the 

 former to touch the latter ; when this has removed the superfluous 



liquid from the section, lay the 

 cover, section upwards, on a 

 glass slip, put on (say) the 

 benzol balsam until it stands in 

 an evenly diffused mound cover- 

 ing the section, and lay it aside 

 absolutely protected from dust 

 for twenty-four hours in order 

 that the benzol may evaporate. 



Now take it out, place upon 

 the centre of the section one 

 small drop of fresh benzol 

 balsam, and turn the cover over 



FIG. 406. on to a warm slip, being careful 



to have guides to the position on 



the slip on which it should be fixed ; and in an hour or so we may 

 clean off superfluous balsam and finish the slide. 



To those who mount much this will prove the quicker plan, as, 

 for fine results, it is undoubtedly the better. 



The above considerations refer only to loose sections in fluid, 

 or thin membranes, or other thin and isolated objects. It is one of 

 the advantages of the paraffin process that with paraffin sections no 

 lifter is required, as these are cut dry, and being stiffened by the 

 paraffin may be lifted by means of a flat camel's-hair brush, or a 

 scalpel or forceps. The manipulations of mounting series of sections 

 on one slide are described under ' Imbedding Methods.' 



When the preparation has been previously immersed in aqueous 

 liquids, and is to be mounted in glycerin, glycerin jelly, or 

 Fan-ants' medium, the best mode of placing it on the slide is to float 

 it in a saucer or shallow capsule of water, to place the slide or cover 

 beneath it, and, when the object lies in a suitable position above it, 

 to raise the slide or cover cautiously, holding the object in place by 

 a needle, until it is entirely out of the water ; and the small quantity 



