THE MICROSCOPE. 



141 



the benzole with the forceps, and thrust into it — the balsam — gently, 

 but firmly; and then with one of the needles it is to be pushed down 

 upon the slide, (into firm contact with its surface, in fact), and ar- 

 ranged in proper position. Now mark this point carefully. If the 

 object be left suspended in the drop of balsam, as soon as the cov- 

 ering glass is applied, it will float out of position, and much valuable 

 time, and more patience be consumed in getting it back, together 

 with the added risk of destroying it in the attempt. But if it be 

 placed in close contact with the surface of the slide, it will become 

 firmly fixed. The forceps having been wiped clean (it is still better 

 to have a second and heavier pair for this purpose), one of the 

 cleansed covers is taken up by them, slightly warmed over the lamp, 



Drying Oven. 



and gently laid upon the balsam, which will spread out under its 

 warmth, if the operation be successfully performed, as the cover 

 settles down to its level. This can be aided by carefully warming 

 the slide over the lamp, holding it in a perfectly level position, and 

 the warming should be continued until the fluid balsam has reached 

 the edge of the cover all around, when the slide should be set aside 



