INDEX 



311 



Mirror, contoring, 138 



coiicavo, 31, 137 

 aperture of, 137 

 when superfluous, 204 



divided, 41 



pivots of, 138 



plane, 31, 137 

 care of, 176 



practical points, 145 



summary, 144 

 Moeller, test slide, 43 

 Monobromide of naphthalin, 104 

 Monocular, practical points, 58 



yellow-green filters for, 75 

 Mounting media, 101, 102 



care of, 177 

 Mus, chromosomes of, 237 

 Muscae volitantes, 50 

 Muscle fiber, Uving, 240 



N 



Nelson, achromatic condenser, 11 

 Cassegrain condenser, 202 

 correction of condensers, 86 

 diaphragm in drawtube, 56, 143 

 double prism, 41 

 four-fifths cone, 92 

 illumination, 67 

 large cones, 203 

 papers on, 211 

 rackwork on drawtube, 56 

 resolution with dark field, 203 

 Nelson's method, improvements in, 



68 

 Nitella, antheridia, 231 

 Nosepiece, revolving, 139 

 care of, 181 



centering objectives on, 140 

 practical points, 145 

 summary, 145 

 testing, 174, 268 

 Numerical aperture (see aperture) 



O 



Object-field, 28 

 OI)joct, in balsam, 99 

 classification of, 105 



Object, distance from front fociil 



lilatic, 116 

 for dry ol)jectives, 107 

 in immersion oil, 99 

 for low-power Greenough, 105 

 microscopic, fixing and staining, 



241 

 for oil-immersion objectives, 108 

 practical points, 109 

 for spectacle magnifiers, 105 

 for twin-objective binocular, 105 

 submicroscopic, 101 

 summary, 108 

 uncovered, 263 



objectives for, 265 

 for water-immersion objectives, 



107 

 in watery media, 99 

 Objective changers, 126, 141 

 circle, 29 

 40, 118 



120, for photography, 124 

 10, 117 



20, for dark field, 93 

 Objectives, 116 

 achromatic, 156 



and apochromatic, 125 



origin, 197 

 adjusting, 121 

 apochromatic, 156 



origin, 199 

 back of, 182 

 capability of, 61 

 care of, 127, ISO 

 centering, 126, 140 

 choice of, 122 

 cleaning, 180 

 in dessicator, 127, 181 

 dry, 33, 111, 259, 267 

 focal lengths, 117 

 focusing, 33 

 fluorite, 124 

 formed of rings, 203 

 high dry, 158 



with wrong covers, IIQ 

 histological, 203 

 low oil-immersion, 118 

 magnification, 149 



