Focus, Principal, 5 



Virtual and Real, 6 



Focusing the Condenser, 161 



Focusing the Objective, 124 



Focusing with Fine Adjustment, 128 



Glass, Crown and Flint, 13 



Jena, 57 



Glass Stage, 39 



Graduated Head, 48 



Graduated Stage, 38 



Hastings' Aplanatic Triplet, 16 



Head, Micrometer Screw, 48 



High Power Objectives, . 63, 99 



How to Focus, 125 



Test Objects for, 133 



Holders, Stands and Dissecting Microscopes, 18 



Homogeneous Immersion Fluid, 61 



Homogeneous Immersion Objectives, 60, 75, 146 



Huyghenian Eyepieces, 107 



Illuminating the Object, 23, 120, 124, 159, 164 



Illuminating Objectives, 64 



Illuminating Opaque Objects, 152 



Illumination with Substage Condenser, 154 



Image, Magnified, 27 



Real and Virtual, 8, 59, 105, 106 



Immersion Fluid, 61 



Immersion Objectives, 60. 75, 146 



Applying Oil to, 146 



Test Plate with, 147 



Index, 48 



Index Eyepiece, 111 



Iris Diaphragm, 54, 129, 157, 158 



Jena Glass, 57 



Joint for Inclination, 52, 184, 197 



Kellner Eyepiece, 10 



