CHAPTER V. 



SLIDES AND COVER-GLASSES, MOUNTING, LABELING 

 AND STORING MICROSCOPICAL PREPARATIONS— EX- 

 PERIMENTS IN MICRO-CHEMISTRY. 



APPARATUS AND MATERIAL FOR THIS CHAPTER. 



Micrescope, compound and simple (Ch. I) ; Micro-Spectroscope and polari- 

 scope (Ch. IV) ; Slides and cover-glasses (§? 158, 160) ; Cleaning mixtures for glass 

 (I 164) ; Alcohol and distilled or filtered water (\ 161) ; Fine forceps for handling 

 cover-glasses (Jg 161, 172); Old handkerchiefs or Japanese paper (|| 72, 161); 

 Paper boxes for storing cover-glasses (%% 161, 163) ; Cover-glass measurer ; Mount- 

 ing material, — Farrant's solution, glycerin, glycerin-jelly and Canada balsam 

 (11 188-191) ; Centering card and lined card for serial sections ($ 172) ; Net-mi- 

 crometer for arranging minute objects like diatoms ($ 195) ; Labels, ($ 194) ; Car- 

 bon ink for writing labels (§ 182) ; Faber's pencils for writing on glass, china, etc. 

 {I 186) ; Writing diamond (g 182) ; Shellac cement [U 169, 193) ; Cabinet {I 183) ; 

 Reagents for experiments in micro-chemistry (£ 196). 



The laboratory furnishes all of the above articles except a simple microscope, 

 slides and cover-glasses, fine forceps, handkerchiefs, paper boxes and Faber pen- 

 cils. 



SLIDES AND COVER-GLASSES. 



§ 158. 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 examina- 

 tion. The size that has been almost universally adopted for ordinary 

 preparations is 25x76 millimeters (1x3 inches). For rock sections, 

 slides 25 x 45 mm. or 32 x 32 mm. are used ; for serial sections, slides 

 50 x 75 mm. or 37 x 87 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. 



§ 159. Cleaning Slides. — For new slides a thorough rinsing in clean 

 water with subsequent wiping with a soft towel, and then an old soft 

 handkerchief, usually fits them for ordinary use. If they are not satis- 

 factorily cleaned in this way, soak them a short time in 50% or 75% 

 alcohol, let them drain for a few moments on a clean towel or on blotting 

 paper and then wipe with a soft cloth. In handling the slides grasp 

 them by their edges to avoid soiling the face of the slide. After the 



