CONTENTS ix 



PAGE 



1853. ' Report on Work done in Acoustics in 1848.' Fortschr. 

 d. Physik. 



'On the Scientific Researches of Goethe.' (Lecture at 

 Konigsberg.) (Trans.) Helmholtz, Pop. Set. Lect., Series I 103 



' On a Hitherto Unknown Alteration in the Human Eye 

 during Accommodation.' Berl. Monatsber. . . . 107 



First Journey to England 109 



1854. ' Reply to the Observations of Dr. Clausius.' Poggend. 

 Annal., XCI 115 



' On the Interaction of Natural Forces.' Lecture, 

 (trans.) Phil. Mag. [4], XI ; Pop. Set. Lect., Series I . . 120 



'On the Rate of Certain Processes in Muscle and Nerve.' 

 Berl. Monatsber 125 



1855. ' On the Composition of Spectral Colours.' Poggend. 

 Annal.,XClV 131 



' On the Sensibility of the Human Retina to the Most 

 Refrangible Rays of Solar Light.' Poggend. Annal., XCIV 133 



'Addendum to a Paper by E. Esselbach on the Measure- 

 ment of the Wave-Length of Ultra-Violet Light.' Berl. 

 Monatsber. 134 



' On the Accommodation of the Eye.' Graefe's Archiv 

 fur Ophthalmologie 134 



' On Human Vision.' (Konigsberg, Lecture) . . . 138 



First meeting with W. Thomson (Lord Kelvin) . . 145, 

 PROFESSOR OF PHYSIOLOGY AND ANATOMY AT BONN, 1855-1858 147 



1856. 'On the Movements of the Thorax.' (Bonn, Nieder- 

 Rheinische Gesellschaft) 148 



'Contraction -Curves of Frogs' Muscles.' Nieder-Rh. 



Sitzungsber. 149 



' On the Explanation of Lustre.' Nieder-Rh. Sitzungsber. 149 

 ' On Combination Tones.' Poggend. Annal., XCIX . 151 

 ' The Action of the Muscles of the Arm.' (Lecture, Bonn) 

 ' The Telestereoscope.' Pogg. Annal. 

 Textbook of Physiological Optics. Part I . . . 155 



1857. ' On the Vowel-Tones.' Letter to Bonders . '.158 



1858. ' On Integrals of the Hydrodynamic Equations which 

 express Vortex-Motions.' Crelle's Journ., LV, (trans.) Phil. 

 Mag. [4], XXXIII . . . . . . . .167 



' Sur le Mouvement le plus general d'un Fluide.' ' Sur 

 le Mouvement des Fluides.' ' Reponse a la Note de 

 M. J. Bertrand du 19 Octobre 1868' 170 



