266 The Microscope. 



INSECT PREPARATION. 



SECOND l-APER. 



B. F. QUIMBY. 



OiNCE the writiag of the first paper, some experiments with the 

 ^^ hypodermic syringe have shown its use in the arrangement of 

 the membraneous wings which often become so twisted that they 

 cannot be brushed out and are very liable to be broken in the 

 attempt. Removing the insect on the glass slip from the water, the 

 syringe may then be used in throwing streams over and under the 

 wings; thus untwisting and spreading them out, using the bnishes 

 at the same time : one in holding the insect in position and the other 

 to aid in the adjustment. 



An effective way to direct a stream under a wing is to pass the 

 needle under the insect so that the orifice may be where the wing 

 joins the body, thus the out-flow will be lengthways of the wing. 

 The syringe may be made very useful in other ways in the process 

 of cleaning. 



MOUNTING. 



Remove the insect from the oil of cloves and place it in 

 turpentine contained in a solid watch-glass. Oar purpose in doing 

 this is to remove the surplus of cloves, which will interfere with 

 the subsequent hardening of the balsam. Place the watch-glass on 

 the plate-glass of the dissecting-box illuminated and examine the 

 insect carefully. If any dirt is found it may sometimes be removed, 

 if on the outside, by brushing. Use two of the biiishes not used in 

 previous cleaning processes. To make sure as to the condition of 

 the insect, place the watch glass on the stage of the microscope 

 and examine. 



Having ready a glass slip and cover-glass of suitable size, both 

 carefully cleaned, adjust the glass of the mounting-box placed in 

 such position that the under illumination may be best reflected into 

 the cupola-like top bearing a slip of glass having upon it a colored cen- 

 tering ring, on which place the slip to be used for mounting the insect. 



Then using the medium-dropper, put only enough Canada bal- 

 sam on the center of the slip to spread out under the whole insect 

 when placed in position. With pliers draw the insect carefully out at 

 one side of the watch-glass, draining off the turpentine and avoiding 

 as much as possible deranging the wings. Then with care drop the 

 insect on the balsam prepared on the slip. Lat the contact be at one 

 end of the insect, lowering gradually to avoid making bubbles which 



