CHAPTER IX 



SLIDES AND COVER-GLASSES; MOUNTING; ISOLATION; 



LABELING AND STORING MICROSCOPIC 



PREPARATIONS; REAGENTS 



SLIDES AND COVER-GLASSES 



? 329. Slides, Glass Slides or Slips, Microscopic Slides or Slips. — 

 These are strips of clear flat glass upon which microscopic specimens are usually 

 mounted for preservation and ready examination. The size that has been 

 almost universally adopted for ordinary preparations is 25 ■ 76 millimeters (1 

 3 inches). For rock sections, slides 25 X 45 mm. or 32 X 32 mm. are used; 

 for serial sections, slides 25 76 mm., 50 - 76 mm. or 38 > 76 mm. are used. 

 For special purposes, slides of the necessary size are employed without regard 

 to any conventional standard. 



Whatever size of slide is used, it should be made of clear glass and the 

 edges should be ground. It is altogether false economy to mount microscopic 

 objects on slides with unground edges. It is unsafe also as the unground edges 

 are liable to wound the hands. 



Fig. 187. Glass slide or slip of the ordinary size for microscopic work (3 

 xi in., 16 x 25 mm. ). (Cut loaned by the Spencer Lens Company). 



Thick slides are preferred by many to thin ones. For micro-chemical 

 work Dr. Chatnot recommends slides of half the length of those used in ordi- 

 nary microscopic work. From the rapidity with which they are destroyed, he 

 thinks the ground edges are unnecessarily expensive. He adds further: " It 

 is a great misfortune that the colorless glass slips used in America and so excel- 

 lent for ordinary microscopic work should be easily attacked by all liquids; 

 even water extracts a relatively enormous amount of alkalies and alkaline 



