INDEX 



159 



Electric light in photo-micrography, 2, 3 

 Enlarging from primary negative where only one 



or two copies are wanted, 29, 30 

 Equally illuminated field, the importance of, in 



photo-micrography, 21 

 Exposure with Edwards's isochromatic backed 

 plates and Edwards's " Antihalo " in low- 

 power photo-micrography, 22 

 for "snap-shot" plates, 142 

 medium-power photo-micrography, 127 

 shutter, author's, 107 

 shutter by Watson, 108 

 Eye-pieces, 90 



F 



Faults in albumenised prints, 45 



in photo-micrographs, 152 



in wet plates, 41 

 Fine adjustment, how to clean in Zeiss models, 

 72 



adjustment illustrated, 70, 71 

 adjustment in microscope, 70 

 Firth, diatom mounter, 130 



Fixing solution for negatives and lantern plates, 34 



solution for wet collodion plates, 39 •• 

 Focal length of lenses in low-power pJlo&-»ml&rQ^ , 

 graphy formulse, 22, 23 ' *' 



Focussing in low-power photo-micrography, 17 j •. ^ 

 medium -power and critical photography, ^20;* 

 137 



Formula for ascertaining length of camera to be 

 used for given lens in low-power work, 23 



for ascertaining magnification of object with 

 given lens and camera length, 23 



for ascertaining JST. A. of dry objectives — 

 Conrady, 90 



used for developing Edwards's plates, 33 



for developing wet plates (collodion), 40 



for developing lantern slides, 33 



for developing Nikko prints, 33 



for intensifying gelatin plates, 126 



for intensifying wet plates, 41 



for thinning gelatin plates, 124, 125 



for toning silver prints, 44, 45 



for use of lenses in low-power work, 23 

 Forrester's " efiective backing " for use in photo- 

 micrography, 20 

 Fram model microscope for photo-micrography, 67 



G 



Gas-bottle regulators, by Beard, 9 

 gauges, 9 



Gas-bottles, Board of Trade regulations, &c., 8 



Gatrell, diatom mounter, 130 



Gauges for cylinders (Beard's), 9 



Glasses for contrast, their utility discussed, 145 



Gwyer mixed-gas jet, 5 



H 



Heliostats, I r, 12 



High-power photo-micrography, i, 134 

 How to use the limelight, 6, 10 



to avoid accidents when using gas-cylinders, 8 



Illuminants, 2 



Illuminating, difierent methods of, 130 

 Illumination, dark ground for objects placed on 

 microscope, 112, 132 

 of objects by large cone, small cone, and 



hollow cone of light, 92-113 

 of objects placed on the microscope, 110 

 oi opaqii.S ab'jetJtj,*} i^,If ^^;** 

 Immersioii lehsb's, 'w^y t*heyJ give so much more 



; . light, 84.^. . 

 ,,*•*, how to": ptfaf(jgr|-g^\with, 1 35 seq. 

 Incandescent gas in *plio£o-micrography, 2 

 Intensifying collodion plates, 41 



gelatin plates, 126 

 Introduction to photo-micrography, i 



Jets, blow-through, 7 

 mixed, 3, 4, 5, 6 



Lantern-slides by dry collodion plates, 39 

 by printirg-out emulsion, 39 

 exposure, 36 

 faults. 37 

 how to make, 36 



