12 



Anniversary Address by Lord Rayleigh. [Nov. 30, 



entirely novel conception and differentiation of the functions of the peripheral 

 nerves, and of the paths for the respective forms of sensibility which they 

 convey — epicritic, protopathic, and deep sensibility. This is generally 

 regarded by neurologists as a research of quite exceptional originality 

 and ability. 



Following the course of afferent impulses, Head next showed (1906) that 

 the sensory paths of the peripheral nerves at their first synaptic junction with 

 the spinal cord become re-arranged, and ascend in different relations in 

 certain definite tracts. 



Davy Medal. 



The Davy Medal is awarded to Prof. "William Augustus Tilden, F.K.S. 



The researches of Prof. Tilden extend into many domains. His work 

 on the specific heats of the elements in relation to their atomic weights, 

 described to the Society in the Bakerian Lecture for 1900 and in two later 

 papers published also in the ' Philosophical Transactions,' was of high 

 theoretical importance. The employment of liquid oxygen as an ordinary 

 laboratory reagent, rendered possible by the researches of Dewar and others, 

 enabled Prof. Tilden to test the validity of Dulong and Petit's Law and 

 of Neumann's Law over a much wider range of temperature than was 

 possible before, and gave a truer estimate of the nature of their validity. 



In the region of organic chemistry, he has carried out important researches 

 on the terpenes, such as that on the hydrocarbons from Pinus sylvestris, on 

 terpin and terpinol, and on limettin. 



In inorganic chemistry, his investigation on aqua regia and on nitrosyl 

 chloride are especially noteworthy. He has assisted much in clearing up 

 many points with regard to aqua regia about which obscurity remained. 

 His introduction of nitrogen peroxide and especially of nitrosyl chloride as 

 reagents has proved, in his own hands and in those of other workers, to be of 

 very high value. 



Darwin Medal. 



The Darwin Medal is awarded to Prof. August Weismann for his contribu- 

 tions to the study of evolution. He was one of the early supporters of the 

 doctrine of evolution by means of natural selection, and wrote in support of 

 the Darwinian theory in 1868. His great series of publications from that 

 date onward must always remain a monument of patient inquiry. In 

 forming an estimate of his work it does not seem essential that we should 



