CONTENTS Xi 



PAGE 



The Jentzsch reflecting condenser 122 



The immersion ultramicroscope 123 



CHAPTER VI. 



USEFUL MICROSCOPE ACCESSORIES; LABORATORY EQUIPMENT; WORK TABLES; 



RADIANTS. 



Drawing cameras 127 



Drawing eyepieces 130 



Microspectroscopes 131 



Calibration of microspectroscopes 135 



Mechanical stages 138 



Rotating and orientating devices : 141 



Lens holders 145 



Reagent containers 145 



Rods, platinum wires, pipettes 148 



Spatulas 148 



Forceps 149 



Object slides 149 



Watch glasses and evaporators 152 



Burners for microchemistry investigations 153 



Tongs 155 



Work tables 156 



Microscope Lamps 158 



Nosepieces and objective changers 164^ __ 



Sedimentation glasses 165 



The microscope as a polarimeter 166 



Cover-glass and object slide gauge 1 68 



Microtome 169 



Tools 169 



Sieves 171 



CHAPTER VII. 

 MICROMETRY; MICROMETRIC METHODS. 



Determination of magnification 172 



Different methods of measuring microscopical objects 175 



Units employed 175 



Methods of direct comparison 1 76 



Micrometric microscopes 177 



Micrometry with the mechanical stage 180 



Micrometry with a camera lucida 180 



Micrometry by means of micrometer oculars 181 



Determination of the ocular micrometer ratio 182 



Step micrometers . 185 



Contrast micrometers . . 185 



Filar micrometers. . 186 



