lilNNEAN SOCIETY OF LONDON. IX 



remote intervals that we can reasonably expect any sudden and 

 brilliant innovation which shall produce a marked and permanent 

 impress on the character of any branch of knowledge, or confer a 

 lasting and important service on mankind. A Bacon or a Newton, 

 an Oersted or a AVheatstone, a Davy or a Daguerre, is an occa- 

 sional phenomenon, whose existence and career seem to be espe- 

 cially appoLQted by Providence, for the purpose of effecting some 

 great important change in the condition or piirsuits of man. 



The establishment of the inductive method (by which the whole 

 face of philosophy, before chaotic, was reduced to order), the dis- 

 covery of the law of gravitation, the invention of the electric 

 telegraph, or the production of sun-pictures — these and similar 

 results of genius, by which the advance of knowledge and the 

 designs of Providence are carried forward by grand and unex- 

 pected impulses, are occurrences, the like of which we must not 

 expect to have annually to record. 



Nor are even the striking examples to which I have referred, 

 influential as they are and original as may be the genius which 

 finally applies them, usually isolated or sudden. The suggestions 

 of previous experiment or discovery, the hints which are given 

 from time to time by either fortuitous or anticipated phenomena, 

 ordinarily afford the ground upon which the most important dis- 

 coveries or improvements are made. The electric telegraph may 

 be traced from the fii'st intimation of the possibility of the trans- 

 mission of the electric force to a distance, through successive 

 occasional advances, to the happy hour when Oersted discovered 

 the great truths of electro-magnetism, and Wheatstone applied 

 the discovery to a purpose which is destined to affect, more than 

 any other single practical application of science that was ever 

 made, the condition, the destinies, and the welfare of mankind. 

 In like manner the consecutive suggestions of Watt, of Davy, of 

 Talbot, of Hersehel, of Daguerre, of Niepce de St. Victor and 

 others were required to bring to even its present state of advance- 

 ment, the art of photography. The history of almost every scien- 

 tific discovery of importance would afford similar illustrations, 

 which will suggest themselves to your minds, and which it is 

 unnecessary for me to enlarge upon. 



Of the results of such successive developments as those to which 

 I have referred, in those departments of science which are usually 

 considered as of a more abstract character, and in those which ai'e 

 properly the subject of expei"imental processes, the late President 

 of the Eoyal Society gave at their last Anniversary some very 

 instructive examples in his lucid and interesting address, which 



