INDEX. 



381 



Roflexions in Polarisation, 305. 

 Refracting surfaces, distances between, 



6, 33. 



,, ,, property of re- 



uniting in a point 

 rays emanating 

 from a point, 6. 



,, ,, -rmination of 



Optical Cardinal 

 points of, 23 ; 

 184-188, 



,, ,, Curvature of, in- 



fluence upon Cur- 

 vature of Image- 

 surface, 75-78. 



, , systems, analytical determina- 

 tion of path of 

 rays in, 9-23. 



,, ,, Convergent and Di- 



vergent systems, 17. 

 ,, ,, determining Optical 



Cardinal-points of, 

 23 ; 184-188. 

 Refraction, as expounded by Gauss, 3 et 



seq., 24. 



,, Chromatic aberration, 50-53. 

 ,, Interference due tf>, 244-247. 

 ,, Lateral Displacement of co- 

 loured Objective images, 52. 

 ,, Spherical aberration, 53-65. 

 ,, of Eye-piece, 34. 

 Riddell's observation of pseudoscopic 

 effect in his catoptric binocular 

 Microscope, 224. 

 Robinson's method of determining Angle 



of Aperture, 175-176. 

 Rotation of objects, 315-319. 



SCHACHT'S " Lehrbuch der Anatomic and 



Physiologic, " 301. 

 Schieck's Aplanatic Eye-piece, 44. 

 Schleiden on Illumination, 104 (note}. 

 Schmidt's (C. ) Goniometer, 294-295. 

 Schrceder's Aplanatic Eye-piece, 44. 

 Scissors for preparing specimens, 278. 

 Sealing, hermetic, of objects, 283. 

 Sections See Objects. ' ' 

 Seibert's Periscopic Eye-piece, 44. 

 Side-reflector, silver or parabolic, 113 (note). 



Sight, short, in persons, differences in 



magnifying power caused by, 37. 



,, "Comparison* of magnifying powers 



for different ranges of, 37. 

 Solid glass Eye-piece, 45. 

 Sojininering's -Mirror, 298. 

 Specimens See "Objects." 

 Spectral Eye-piece, 47-48. 

 Spermatozoa, observation of motion of, 



252. 

 Spheres, Hollow, microscopic observation 



of, 206-217. 

 ,, small, reflexion of light by, 236- 



239. 

 Spherical Aberration, 53-65. 



' ,, Testing the, 149- 



158. 



,, ,, in Eye-piece, 62. 



Spiral-threads, drawing of, 302. 

 Stachys spec., example of polarisation, 370. 

 Stage, Object-, 117. 

 Stands, construction of, 116-121. 



,, of modern opticians, 122-125. 

 Starch -grains, example of polarisation, 



372. 



Stilling's method of drawing, 299. 

 Substances, organised, on some structural 



peculiarities of, 366-368. 

 Sugar- water as preserving medium, 283. 

 Surirella gemma, 136, 138. 

 Swarm-spores, observation of motion of, 

 252. 



Taxus baccata L., example of polarisation, 



371. 

 Test-objects, images of wire-gauze as, 127- 



132. 



,, organic, 132-139. 



Test-plate, Nobert's, 139, 140. 

 Testing angle of aperture, 172-177. 

 ,, Cardinal points, 184-188. 

 ,, Centering, 170-171. 

 ,, Chromatic Aberration, 158-167. 

 Flatness of Field-of-view, 168-169. 

 Focal length, 181-183. 

 Magnifying power, 178-181. 

 Optical Power, 126-149. 

 ,, Power of Definition, 148-149. 

 ,, PowerofDiscrimination, (absolute) 

 126-140; (relative) 110-147. 



