Sir H. Davy, Dr. Wollaston, and Dr. Young. 155 



The Leptologist. British Magazine, 1800 ; a Series of Essays on Gram- 

 mar, Criticism, Geometry, Paintings, Manners, Riches, Exercises, Medicine, 

 and Music ; some of them reprinted afterwards. 



There is also an account of the French Calendar and Measures, and an 

 Essay on the Morals of the Germans. 



Experiments and Enquiries respecting Sound and Light. Philosophical 

 Transactions, 1800, p. 106: the vibrations of the air observed by means of 

 smoke ; those of strings counted, and their orbits observed with a micro- 

 scope ; their harmonics suppressed at pleasure. 



A Bakerian Lecture on the Mechanism of the Eye. Philosophical Trans- 

 actions, 1801, p. 23 : describing a new Optometer, and showing that the 

 eye retains its power of accommodation under water ; measuring also the 

 dispersive power of the eye. (Dr. Y. remarks, that he " afterwards found 

 that his own eye lost almost the whole of its power of accommodation soon 

 after fifty, remaining fixed at its greatest focal distance." 



A Letter respecting Sound and Light. Nicholson's Journal, August 



1801, in answer to Professor Robinson, of Edinburgh. 



A Syllabus of a Course of Lectures on Natural and Experimental Phi- 

 losophy ; 8vo. London, 1802: presenting a Mathematical Demonstration 

 of the most important Theorems in Mechanics and in Optics ; and contain- 

 ing the first publication of the general law of the Interference of Light, 

 which has been considered as the happiest result of all the Author's efforts. 

 It was not till the year 1827, that the importance of this law could be said 

 to be fully admitted in England : it was in that year that the Council of the 

 Royal Society adjudged Count Rumford's Medal to M. Fresnel, for having 

 applied it, with some modifications, to the most intricate phenomena of 

 polarized light. 



A Bakerian Lecture on the Theory of Light and Colours ; Phil. Trans. 



1802, p. 12, developing the Law of Interference, and entering into all the 

 details of the theory to which it leads ; dwelling, at the same time, upon 

 the difficult points, with somewhat more of candour than might have been 

 consistent with his object, had he been anxious to obtain proselytes. 



An Account of some Cases of the Production of Colours, p. 387, con- 

 taining a simpler statement of some applications of the same law, intended 

 to exhibit the facts in a more concentrated form. 



A Reply to Mr. Gough's Remarks. Nicholson, November, 1802, p. 1. 

 This Letter, together with some subsequent Correspondence, relates princi- 

 pally to the coalescence or composition of Sounds, affording an analogy to 

 the interference of Light. 



Journals of the Royal Institution, 8vo. London, 1802-3. A first volume, 

 and part of a second were edited, and chiefly written, by Dr. Young. 



Experiments and Calculations relative to Physical Optics. Phil. Trans. 

 1804, p. 1. Another Bakerian Lecture, continuing the demonstration and 

 the application of the Law of Interference. 



