320 



INDEX 



Opaque objects, illumination of, 61 ; 

 by bull's-eye, 61, 63 ; by para- 

 bolic side-reflector, 64 ; by 

 Sorby parabolic reflector, 64 ; 

 by Lieberkuhn reflector, 65 ; 

 by reflecting glass for low 

 power, 65 



with oblique beam, 61-63, 285, 

 286 ; by vertical illuminator, 

 62, 68, 141, 256, Watsons', 66, 

 Zeiss, 66, Leitz, 67, Rosen- 

 bain's, 68, 261, in Leitz 

 micro-metallograph, 142-144 ; 

 examples, 303, 304; vide 

 Metal Surfaces 



Opaque screen for centreing, &c., vide 

 Projection-image 



Orthochromatic plates, 200, 220, 284 



Orthonies splendida, 292 



Ortol, developer, 230 



Over-exposure, 232, 234 



Oxy hydrogen, vide Lime-light 



P.O.P., 238 



Panchromatic plates, 199, 200, 219 

 Parabolic side-reflector, 64 ; Sorby, 64 

 Paraboloid condenser, 54, 57 

 Paraboloidal condenser (Zeiss). 57 

 Pathological specimens, 162, 273 

 Pendant Saturator (Willway and 



Sons), 84 



Penetration, 1, 21 ; to obtain, by 

 reducing aperture of sub-stage 

 condenser, 22, 296, 299, by reduc- 

 ing aperture of objective, 22, 24, 

 286 ; as affected by density of 

 medium, 24, by focal length of 

 objective, 24, by combination of 

 objective and ocular, 43, 1 94 ; 

 in low-power work, 24, 286 ; in 

 stereoscopic work, 274 

 Pepper, stem of black, 288 

 Perchloride of iron, 180 

 Petroleum lamps, vide Oil lamps 

 Photo- micrography, its field, 3 ; how 

 to begin, 4 ; progressive example 

 of, 283 ff. 



P;cric acid, 211, 284, 288 

 Pigg, J. I., 176 



Planar lenses, 33, 181, 284, 286 

 Plates, vide Sensitive plates ; for 

 lantern -slides, 242 ; for coloured 

 lantern-slides, 277, 280, 282 

 Plate-carriers, 181 ; tests for regis- 

 tration, 182 



Plate-cultures of bacteria, 268 

 Pleurosigna angulatum, 29, 301 ; as 

 test for objective, 159 



Podura scale, as test of objective, 

 28, 29 ; for correction for cover- 

 glass thickness, 159 ; examples, 

 300, 301 



Pringle, Andrew, lime-light cut-off 

 tap, 87 ; microscope, 9 ; photo- 

 micrography apparatus, 129 



Printing, 237 ; by daylight (P.O. P.), 

 238 ; by artificial light (bromide), 

 239, 240 ; to glaze the print, 241 ; 

 in lantern-slide making, 242, 244 



Projection, preliminary experiments 

 in, 147 ; of lantern-slides, 249 



Projection-image on opaque screen, 

 154 ; use of, for centreing, 164, 185, 

 186 ; for studying collecting-lens 

 effect, 173 



Projection-oculars, vide Oculars, pro- 

 jection 



Projector Nernst lamp, 91 



Pyrogallic acid, 230, 240 



QUARTZ, tubes for mercury-vapour 

 lamp, 94 ; in ultra-violet light 

 apparatus, 251-253, 255 



RAMSDEN, disc, 224 



Realgar, 24 ; refractive index of, 306 



Reducing, 236 ; in lantern-slide mak- 

 ing, 245 



Reduction, distance of lens from 

 focussing- screen for, 306 



Reflex camera, 140, 141, 295 



Refraction, 19 



Refractive index of mounting 

 medium, 24, 156 ; of agar, 268 ; 

 of cedar-wood oil, 19 ; of glass, 

 157, 306 ; table of, for various 

 substances, 306 



Reichert, C., microscope stand, 17 ; 

 objective, 292 



Reid, Dr. D. J., 224 



Research microscope, 14 



Resolving power, 26, Abbe's law, 

 215; dependent on N.A., 25, 31, 

 on wave-length, 250 ; with dark- 

 ground illumination, 60 ; as 

 affected by condenser aperture, 

 161 ; by violet light, 215, by ultra- 

 violet light, 250, 251 ; of' plates, 

 221 



Rheinberg, J., 274 



Ringworm, surface colony of, 291 ; 

 in human hair, 297 



Rockers, 201, 233 



Rosenhain, W., vertical illuminator, 

 68 ; metallurgical microscope, 259 ; 

 coloured glass screens, 261 



