160 



INDEX 



Lantern -slides, yellowing of, 38 



wet collodion plates, 39 

 Law of Snell, 82 

 Leitz's objectives, 78 



Lens, ordinary photographic, how to ascertain its 



N. A. with any diaphragm, 147 

 Lenses, dry, ascertaining N. A. by Conrady's 



method, 90 



for low-power photo-micrography, 16, 17, 

 18, 23 



for photo-micrography, 17, 18, 78, 79 

 for photographing " culture " tubes, 27 

 LieberkUhn, use of, 132 



Light, annular, author's means of obtaining, 95 

 annular, danger of misinterpreting effects 



given by its use, 94 

 annular, for illuminating objects placed on 



microscopes, 112 

 "critical," 103 



different cones of, given by substage con- 

 denser, 92 



direct, for illumination of objects placed on 



microscope, 110 

 monochromatic, 105, 113 

 " double oblique," 1 1 3 



"oblique," danger of misinterpreting effects 

 given by its use, 94 ... 



" oblique," fon iihfminat^p'g objffc'fe placed i)n 

 micrcscopQ,.itfo*«'* • * * **** 



oblique, Zeiss method of pro.ducin^.ojii.4]jica:o- 

 scope. III /.'*.: : .****••• 



polarised, for illumina'tio'n of object placed on 



microscope, 114 

 refraction of, 81 



reflected, for illuminating objects placed on 

 microscopes, 110 

 Lime, zirconium, by Zeiss, 11 

 Limelight in photo-micrography, 3 

 Limes, darkening of, by impurities of coal-gas, 137 



for limelight, 1 1 

 " Limiting " angle, 83 



Lines to inch, &c., how to ascertain in a speci- 

 men, 148 



how to ascertain by photographic method, 

 149 



Low-power work, author's arrangement, 14, 24, 27 

 apparatus, dimensions, 25 

 photo-micrography, i, 13 

 photo-micrography apparatus, use in, 13 



Low-power photo-micrography, diagram of appara- 

 tus, 14 



Lumifere's plates for photo-micrography, ig 



M 



Magnification different meaning of terms, areas, 

 and diameters, 114 

 given by different foci usually adopted, 116 

 of delicate details how to ascertain, by micro- 

 meter, 148, 149 

 of object placed on microscope, how to obtain, 

 116, 117 



how the same can be obtained with different 

 eye-pieces, objectives;, and camera lengths, 

 128 



obtained by different arrangements of appar- 

 tus, how to decide which is the best, 

 128 



Mechanical stage, the, 75 



stages of different patterns, removable, 76 

 Medium power photo-micrographs, i, 47, 109 

 " Memoranda " concerning high-power photo- 

 micrography, 142 

 Metric measures, with their English equivalents, 



;Mi^r.os/;C>pe« and camera, excluding light from 



junction of, 118 

 Microscope, how to fix on photo-micrographical 

 '\ I table, 118 



illumination of objects, placed thereon, 110 

 Mixed jets used in photo-mici-ography, 3 



jet, working directions, 6 

 Moller, diatom mounter, 130 

 Monochromatic light, 105, 113, 145 



screens, how made, 145, 146 



their utility discussed, 145 

 Movable substage, 77 



N 



Navicula LYRA, compaHson of photographs with 

 high and low apertures, 137 

 how to photograph, 136 

 rhomboides, how to photograph, 137 

 spectabilis, how to photograph, 135 



Negatives, drying of, 35 



Nelson, model by Baker for photo-micrography, 60 



