x CONTENTS 



PAGE 



1858. 'On the Subjective After-images of the Eye.' 

 Nieder-Rh. Sitzungsber. 171 



'On After-images/ (Karlsruhe, Naturf.-Versammlung) 172 

 ' On the Physical Causes of Harmony and Dissonance/ 



(Karlsruhe, Naturforscher-Versammlung) . . .172 



'On the Physiological Causes of Harmony in Music/ 



(Bonn, Lecture). Pop. Set. Lect., Series I . . . .172 



PROFESSOR OF PHYSIOLOGY AT HEIDELBERG, 1858-1871 . . 176 



1859. 'On the Quality of Vowel-Sounds/ Poggend. 

 Anna!., CVIII ; (trans.) Phil. Mag. [4], XIX . . .178 



' On Timbre/ (Heidelberg Scientific and Medical Society, 

 1860) 180 



'On Aerial Vibrations in Tubes with Open Ends/ 

 Crelle's Journal, LVII 180 



'On Colour- Blindness/ (Heidelberg Society) ... .183 



Death of Helmholtz's first wife 185 



1860. ' On Friction in Liquids/ Vienna, Akad. d. Wissensch. 186 

 ' On Contrast Phenomena in the Eye/ (Heidelberg Soc.) 187 

 Textbook of Physiological Optics. Part II . . .191 

 ' On Musical Temperament/ (Heidelberg Society) . 194 

 ' On the Persian and Arabian Scales/ (Heidelberg Soc.) 196 

 'On the Motion of the Strings of a Violin/ Glasgow, 



Proc. Phil. Soc., V 196 



1861. ' On the Application of the Law of the Conservation of 

 Force to Organic Nature/ Proc. Roy. Inst., Ill . . 199 



Marriage with Fraulein Anna von Mohl . . . . 200 

 'Contribution to the Theory of Reed-pipes/ Pogg. 



Ann., CXIV 205 



' On a General Method of Transformation of the Problems 



concerning Electrical Distribution/ (Heidelberg, Dec. 8) . 206 



1862. Pro- Rector of Heidelberg University . . . 211 

 ' On the Relation of the Natural Sciences to Science in 



general/ Pro-Rectorial Address, (trans.) Popular Scientific 



Lectures, Series I 211 



'On the Horopter/ Graefe's Archiv, 1864. 'Remarks 

 on the Form of the Horopter/ Pogg. Ann., 1864 . . 213 



1863. The Theory of the Sensations of Tone as a Physio- 

 logical Basis of the Theory of Music. (Translated by 



A. J. Ellis) . 213 



Note on the Signification of Historical Researches in 

 Branches of the Natural Sciences. 



