THE STORY OF NINETEENTH-CENTURY SCIENCE 



had founded, and of which Davy was then Professor of 

 Chemistry the institution whose glories have been per- 

 petuated by such names as Faraday and Tyndall, and 

 which the Briton of to-day speaks of as the " Pantheon 

 of Science." Here it was that Thomas Young made 

 those studies which have insured him a niche in the 

 temple of fame not far removed from that of Isaac 

 Newton. 



As early as 1793, when he was only twentj^, Young 

 had begun to communicate papers to the Royal Society 

 of London, which were adjudged worthy to be printed 

 in full in the Philosophical Transactions; so it is not 

 strange that he should have been asked to deliver the 

 Bakerian lecture before that learned body the very first 

 year after he came to London. The lecture was deliv- 

 ered November 12, 1801. Its subject was " The Theory 

 of Light and Colors," and its reading marks an epoch in 

 physical science ; for here was brought forward for the 

 first time convincing proof of that undulatory theory of 

 light with which every student of modern physics is fa- 

 miliar the theory which holds that light is not a cor- 

 poreal entity, but a mere pulsation in the substance of 

 an all-pervading ether, just as sound is a pulsation in the 

 air, or in liquids or solids. 



Young had, indeed, advocated this theory at an earli- 

 er date, but it was not until 1801 that he hit upon the 

 idea which enabled him to bring it to anything ap- 

 proaching a demonstration. It was while pondering 

 over the familiar but puzzling phenomena of colored 

 rings into which white light is broken when reflected 

 from thin films Newton's rings, so called that an ex- 

 planation occurred to him which at once put the entire 

 undulatory theory on a new footing. "With that sagac- 



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