LIST OF ILLUSTRATIONS. xxiii 



FIG. PAGE 



386. Experiment to test Talbot-Plateau law (Helmholtz) ... . . 1069 

 387,388. ,, upon the influence of contrast on flicker sensation- 



(Sherrington) . . . . . . . . 1070,1071 



389. Fechner.'s experiment . . . . .... . 1075 



390. Experiments on flicker (Haycraft) ..... . . 1079 



391. Colour triangle . . . . . .... . 1081 



392. Curve of .luminosity in total colour-blindness (Konig) . . . 1089 

 393,394. Entoptic appearances . . . . . . 1099,1100 



395. Helmholtz's experiment on delicacy of local discrimination in retina . 1101 



396. Curves illustrating the Young-Helmholtz theory of colour vision 



(Konig and Dieterici) . . . . . . . 1106 



397. Curves of sensation in red-green blindness (Konig and Dieterici) . 1107 



398. Curve of spectral and fundamental colours . . . .1108 



399. (Helmholtz) . . 1109 



400. Experiment on single and double vision (Volkmann) . . . 1125 



401. (Wheatstone) . . .1126 

 402-404. Form of horopter (Hildebrand) . . 1127, 1128 

 405, 406. To illustrate Listing's law (Hering) . . . . .1130 

 407. Apparatus for investigating visual localisation (Greeft) . . . 1133 

 408-410. To illustrate geometrical illusions . . . . 1141,1142 



411. Diagram to explain geometrical illusions (Kundt) . . . 1142 



412. (Hering) . 1143 



413. Lipp's experiment on geometrical illusions . . . 1143 



414. Auerbach's experiment ....... 1144 



415. 416. To illustrate Einthoven's explanation of colour stereoscopy . . 1145 



417. Spiral disc illusion ....... 1147 



418. Posterior wall of the cartilaginous and osseous meatus (Politzer) . 1151 



419. Curvature of tympanic membrane (Helmholtz) .... 1153 



420. Illustrates the effect of the curve of the radial fibres of the membrana 



tympani ......... 1154 



421. Eelations of the malleus and incus (Helmholtz) .... 1158 



422. Ear manometer (Politzer) . . . . . . .1162 



423. Various forms of wave curves . . . . . .1172 



424. Form of wave produced by combining two simple waves. . .1173 



425. Compound wave form according to Max Meyer . . . .1193 



426. Diagram showing range of registers of human voice . . .1210 



427. Aperture of glottis during production of low note or lower register 



(Bosworth) . ... . . 1211 



428. Aperture of glottis during production of high note of lower register 



(Bosworth) . . . . . . . .1211 



429. Aperture of glottis during production of a note in the head register 



(Bosworth) , 1212 



430. Pitch of vowels according to Helmholtz . . . . .1215 



431. Konig . . . 1216 



432. Konig's apparatus for illustrating the quality of vowel tones by a 



manometric flame . . . . . . .1219 



433. Flame pictures of the vowels OU, 0, and A (Konig) . . . 1219 



434. Diagram showing the first step in analysing wave-forms . . . 1221 



435. Diagram showing the amplitude as indicated by the height of ordinates, 



of the partials of the Swedish i t sung at pitch of 293 vibs. (Pipping) . 1222 



436. Diagram showing the amplitude in the partials of the German long a, 



sung and analysed by Hermann ...... 1223 



437. Diagram showing the application of Pipping's method 



438. Examples of vowel curves obtained by Hermann . . . . 1226 



