VI 



INDEX. 



PAGE 



Oculars, Projection Recom- 

 mended 37 



Oculars, Zeiss Compensating. 164 

 Oculars, Zeiss' System of Mark- 

 ing 164 



Oil Lamp as Radiant 39 



Oil Lamps for Microscope ... 45 



Opal Prints by Transfer.. 128 



Opaque Mounts 174 



Operating Room 55 



Operating Room, Furniture 



For 57 



Operating Room, Window or 



Lamp for 55 



Operating Room Lamps 56 



Operations Following Devel- 

 opment 101 



Optical Lantern, An Objection 



To 161 



Optical Lantern, for Enlarging. 138 



Optical Lantern, Gas For 159 



Optical Lantern, Jets For 159 



Optical Lantern, Oil Lamp. . . . 158 

 Optical Lantern, Plea For Use 



Of 155 



Optical Lantern, Table of Dis- 

 tances, Foci, Disc, Sizes, etc. 160 

 Optical Lantern, To Get Good 



Light 160 



Optical Lantern ' Carriers". . . 160 

 Optical Lantern to Darken 



Room 159 



Orthochromatic or Color-Cor- 

 rect plates, Light For Devel- 

 oping 55 



Orthochromatic Photography. . 105 

 Orthochromatic Photography, 



Late Advances in 67 



Orthochromatic Work, Samples 



of 109 



Orthochromatics 21 



Orthochromatics, LateAdvances 



in 106 



Orthochromatics, Rationale of. 105 



Orthochromatics, Value of 106 



Orthochromatising Plates 107 



Over-exposure, to Remedy. ... 97 



Oxygen Gas For Lantern 158 



Oxy-hydrogen Lime Light 43 



P. Angulatum 173 



P. Angulatum, Photo'd by 



Maddox 13 



Paper Albumenized, Printing 



on 115 



Parabolic Illuminator 174 



"Paraboloid" 174 



Pellucid Objects. How to Treat 168 



Pellucida, A, " in lines " 171 



Penetration, Aperture, Magnifi- 

 cation 30 



Penetration, Defined 28 



Penetration and Aperture 29 



Penetration in Relation to 



Aperture 163 



Permanence of Bromide Prints 129 

 Perspective, in a Diffraction 



Image 30 



Photographic Requisites 55 



Photography, Color-Correct. . 105 

 Photography, Orthochromatic.. 105 



Photography, Value of 11 



Photography in General, to be 



Studied 21 



Photo-micrographers, Classes 



of 12 



Photo-micrography, Claims for 15 



Pigott, Dr. Royston..! 30 



"Pinholes" in Plates 104 



Pizzighelli's Platinum Printing 



Process 132 



Physio and Patho. Prepara- 

 tions, How to Treat 169 



Plane Mirror, Use of, With 



Daylight 42 



Plate Glass to Focus on 53 



Plates, Common Sizes of 52 



Plates, List of for Stock 68 



Plates, Selection of 65 



Plates, to Orthochromatize 107 



Platinotype, Cold Bath Process 133 

 Platinotype, Hot Bath Process. 131 



Platinotype, Negatives for 130 



Platinotype, Solutions for 64 



Platinotype, To Print on the 



Paper'. 131 



Platinotype for Permanence. . . 130 



Platinotype Printing 130 



Platinotype Prints, Clearing . . 132 

 Platinotype Prints, To Develop 131 

 Platinotype Process of Printing 



Described 131 



Pneumatic Holders 58 



Polariser 85 



Polarizing Apparatus 177 



Potassic Carbonate, Solution. . 62 

 Potassic Ferricyanide, Reducer 63 



Potassic Meta-bisulphite 61 



Potassic Oxalate, Sat. Solution 63 

 Powell and Leland, Their Micro- 

 scopes 24 



Powell and Leland's Apochro- 



matic Condenser 34 



"Power".. 31 



