1894.] President's Address. 41 



Perhaps the most interesting of his experimental investigations in 

 physiological optics was the measurements, by his ophthalmo meter, 

 of the curvatures of the several refracting surfaces constituting the 

 lens-system of the eye, from which he ascertained that it is almost 

 altogether by changing the curvature of the front surface of the 

 crystalline lens that the eye is accommodated by its possessor to 

 vision at different distances. His ophthalmoscope, by which for the 

 first time he himself saw and showed to others the retina of the 

 living eye, was a splendid and precious contribution to medicine. By 

 allowing that outlying portion of the brain to be distinctly seen and 

 examined, it has shown the cause of many illnesses which had been 

 regarded as hopelessly obscure ; and for diagnosis and guidance of 

 medical treatment, ifc is now continually used not only by oculists, 

 but by general practitioners. 



Constrained as I feel not to overtax your patience, I find it impos- 

 sible on the present occasion, to enter upon Helmholtz's researches 

 in mathematics and mathematical physics farther than just to mention 

 his small but exquisite paper on anomalous dispersion, and the grand 

 contribution to hydrodynamics which we have in his " Integrals of 

 the Hydrodynamical Equations which express Vortex Motion."* 



Since our last anniversary, important questions regarding the 

 conduct of the ordinary meetings and the publication of papers, both 

 in the * Transactions ' and ' Proceedings ' of the Royal Society, have 

 been engaging the attention of the Council, with the assistance of a 

 Committee appointed on the 5rh July, 1893. The final report of this 

 Committee was submitted to the Council on the 5th July, 1894, when 

 resolutions were adopted accepting some of its recommendations and 

 deferring the consideration of others until after the recess. 



At the request of the Royal Geographical Society, a Committee 

 was appointed by the Council of the Royal Society to consider the 

 advisability of asking the Government to undertake an Antarctic 

 Expedition. A very important and valuable Report on the advan- 

 tages which such an expedition would bring, both to science and 

 to practical navigation, was presented by this Committee to the 

 Council on. the 24th May. The Council, after much careful consider- 

 ation, resolved to ask the Lords of the Admiralty to grant an inter- 

 view on the subject with representatives of the Royal Society. This 

 request was assented to : and an interview was accordingly held 

 between the First Lord of the Admiralty and representatives of the 

 Royal Society ; but the proposal of an Antarctic Expedition was not 

 favourably received. 



The Joule Fund Committee submitted its report on the 7th 



* 'Philosophical Magazine/ July, 1867, being the translation by Tait of the 

 original German paper, which appeared in Crelle's Journal in 1858, and which has 

 been republished in * Wissenschaftliche Abhandlungen,' vol. 1, pp. 101 134. 



