12 Anniversary Address by Prof. C. S. Sherrington. 



essential an adequate State provision for both these constituent elements, 

 indispensable, since they are, to the whole structure of the system. 

 I now proceed to the distribution of the Medals. 



The Copley Medal is awarded to Sir Joseph Larmor. 



Sir Joseph Larmor has long held a leading position in the British School 

 of Mathematical Physics. There is hardly a branch of this subject to which 

 he has not made contributions of distinct originality and great value. His 

 earlier researches on Dynamics, on Optics, both geometrical and physical, and 

 on Elasticity, are marked by keen insight and by the novelty introduced in 

 the treatment of familiar subjects. In more recent periods he has written on 

 problems of Geodynamics, with the same illuminating force. His contribu- 

 tions to the Theory of Electricity, in its many ramifications, are numerous 

 and profound. His treatise on ' iEther and Matter ' forms a distinct land- 

 mark in the history of the subject. In this we have the foundation of electro- 

 magnetic theory on the single principle of least action, with the electron 

 taken into account as an sethereal structure. He was the first to establish 

 (to the second order of velocity) the correspondence between moving and fixed 

 electrical systems, and shares with Lorentz, the distinction of discovering 

 the generality of this correspondence to any order. It may fairly be said 

 that his preliminary work was of the utmost value in paving the way to the 

 modern developments of the Theory of Relativity. In addition to his own 

 researches Larmor has, as Lucasian Professor, stimulated the work of others 

 with notable success. His intimate and extensive knowledge of the history 

 as well as of the results of physical science marked him out as the appropriate 

 editor of the works of Stokes, Kelvin, James Thomson, and Henry Cavendish, 

 to which he has contributed most serviceable annotations. 



A Royal Medal is awarded to Dr. Frederick Erost Blackman. 



Dr. Blackman is distinguished for his contributions to plant physiology, and 

 especially to knowledge of the process of photo-synthetic assimilation of carbon 

 dioxide. In this connection he devised apparatus of great delicacy and 

 accuracy. Later he proceeded to an exhaustive investigation on the rate of 

 assimilation within the green leaf. He determined, under varied and con- 

 trolled conditions, the inter-relationship of the external factors and their 

 several and joint effects on the rate of assimilation, and has laid the founda- 

 tion on which a good deal of subsequent work by other investigators has been 

 rendered possible. 



He was thus led to his theory of limiting factors, which has exerted much 

 influence in both plant and animal physiology. With the help of his 



