260 



opinion of scientific men seems to be divided as to the reception of 

 this theory ; but whatever may be thought of its truth, it has at least 

 the merit of referring the light and heat to known causes. 



The mathematical theory of magnetism was developed by the illus- 

 trious Poisson, but was made to rest on foundations in some respects 

 too speculative. This subject has been taken up by Professor 

 Thomson, who in a lucid and satisfactory manner has placed the 

 theory on the basis of observed facts, so as to render it independent 

 of any ulterior suppositions which may be adopted respecting the 

 nature of magnetism. Two papers on this subject are published in 

 the ' Philosophical Transactions,' and others, containing the theory of 

 magnetic induction, are promised. More recently Professor Thomson 

 has published a series of papers devoted to the mathematical theory 

 of the submarine telegraph, and has been engaged in a series of 

 experimental researches relating to voltaic electricity, which formed 

 the subject of the Bakerian Lecture delivered in the session just con- 

 cluding, and of which the detailed account will shortly be in the 

 hands of the Fellows of the Society. 



PROFESSOR THOMSON, 



Accept this Medal in testimony of our admiration of your able 

 mathematical and physical researches. 



Obituary Notices of deceased Fellows. 



JAQUES CHARLES FRANOIS STURM was born at Geneva in 

 September 1803, of a family which had quitted Strasbourg in the 

 middle of the last century, where one of his ancestors had been 

 President of the Eepublic at the period of its contests with the 

 Emperor Charles V., and another had attained a distinguished re- 

 putation for his writings on jurisprudence and theology. After 

 completing his school education and his classical studies at the 

 College with remarkable success, he became in his fifteenth year a 

 student of the University of his native city, where his rapid progress 

 in the study of mathematics and philosophy attracted the marked 

 attention of the well-known geometer Simon Lhuillier, who fully 

 anticipated the eminence which he was afterwards destined to attain. 



