298 [Dec. 1, 



a marked influence upon the development of organic chemistry ; an 

 early fruit of which was the discovery by Gerhardt of the organic 

 anhydrous acids, which may be regarded as the application of Dr. 

 Williamson's processes to negative instead of positive radicals. 



A large field of inquiry having been thus opened, a suggestive 

 paper on the Constitution of Salts and Acids speedily followed, in 

 which Dr. Williamson showed that acetic acid is formed by the sub- 

 stitution of one atom of oxygen for two atoms of hydrogen in alcohol. 

 Acetic acid, thus regarded, encloses the new radical othyl or acetyl. 



The question of types and the doctrine of substitution are further 

 elaborated in six memoirs read before the Royal Society in 1854. 



In these researches are exemplified the rarely associated powers 

 of discovering new facts, and of evolving from them truths of a higher 

 order. They also show that the scientific importance of substances 

 must not be estimated by the bare knowledge gained from their ulti- 

 mate analysis, but that valuable generalizations may follow from the 

 establishment of correct ideas of their molecular grouping ; generali- 

 zations, indeed, which effect a new insight into nature, and to a great 

 extent anticipate a rich field of subsequent research. 



PROFESSOR WILLIAMSON, 



In presenting you with this Medal, testifying the value which the 

 Royal Society attaches to the researches on which you have been 

 engaged, I would venture to express on their behalf the hope that, 

 in the many years which we trust are yet before you, science may 

 continue to profit, and may profit largely, by your exertions in 

 researches for which you have shown yourself to be so highly 

 qualified. 



On the motion of Sir R. Murchison, seconded by Mr. Tite, it was 

 resolved : 



" That the thanks of the Society be returned to the President for 

 his Address, and that he be requested to allow it to be printed." 



The Statutes relating to the election of Council and Officers having 

 been read, and Dr. Anderson and Major- General Sir Andrew Scott 

 Waugh having been, with the consent of the Society, nominated 

 Scrutators, the votes of the Fellows present were collected. 



The following Gentlemen were declared to be duly elected as Council 

 and Officers for the ensuing year : 



