96 Modern Microscopy. 



place in acetic acid. Wash away the acid with water, and 

 transfer to a shallow saucer of methylated spirit. Take 

 two needles and lay out the various parts as quickly as 

 possible ; if any parts are troublesome, hold them in 

 position until the spirit has fixed them. Now let it soak 

 for an hour, or until required. Kemove from spirit, place 

 in clove oil, and when clear place in turpentine. 



Take a tin cell just deep enough for the specimen, and 

 apply a coat of Miller's cement to one side of it. Allow 

 this to nearly dry. Clean and warm a slide 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 ; press on the upper side of the cell until it adheres 

 firmly to the slide, and put it away to dry. Fill the cell 

 with Canada balsam, and see that it also flows over the 

 upper edge of the cell, so that it may serve as a cement to 

 fasten on the cover. Take the insect from the turpentine 

 on a lifter, put it in the cell, and with needles rearrange 

 the parts if necessary. Put away out of reach of dust for 

 twelve hours to harden the balsam. Place a drop of balsam 

 on one side of the cell. Clean a cover-glass of the same 

 size as the cell, take it up in a pair of forceps and warm it 

 gently over a spirit-lamp, and bring its edge in contact with 

 the drop of fresh balsam ; ease down carefully, so as to 

 avoid air-bubbles, and press on surface of cover with a 

 needle until it rests on the cell all round. Now take a soft 

 brush and some benzole, and wash away the exuded balsam ; 

 dry with a clean rag, and apply a ring of any good cement. 



To Mount an Insect in Glycerine without Pressure. 

 Many small, soft bisects and their larvae may be mounted 

 in glycerine while fresh. The larger and harder kinds 

 must be soaked in potash to render them transparent. 

 Make a cell of the required size, and fasten it to a slide with 

 Miller's cement as directed for balsam mounts. Apply a 

 coat of Miller's cement to the upper side of the cell, and 

 allow it to nearly dry. Fill the cell with glycerine, and put 

 the insect into it ; spread out the wings, legs, etc. Clean 



