324 NINETEENTH CENTURY. FT. in. 



ferent for each different substance. Malus was the first 

 to call this peculiar effect polarization^ and light which 

 behaves in this way has since been always called * polarized 



l ? ght f 



His discovery led to a completely new study, for people 



had almost forgotten the experiments whiui had been made 

 by Huyghens more than 100 years before ; but this novel 

 and curious fact attracted attention, and the subject was 

 taken up again. Malus did not live to explain the matter ; 

 he found out many remarkable facts about it, but it was 

 Young and the French philosopher Fresnel, who really 

 worked out the theory of the polarization of light. 



Polarization of Light explained by Young and 

 Fresnel, 3816. Augustin Fresnel, the contemporary and 

 friend of Thomas Young, was born at Broglie, in France, in 

 1788. He was a delicate backward boy, who disliked 

 books, but loved practical experiments, and he followed his 

 tastes by becoming an engineer. Being a Royalist, how- 

 ever, he was harshly treated by the Emperor Napoleon I., 

 and he retired to Normandy to devote himself to science. 

 He died of consumption in 1827. 



It is very difficult to decide whether Young or Fresnel 

 was the first to point out how certain peculiar vibrations of 

 the ether explain the polarization of light. But fortunately 

 this need not trouble us, for the men themselves were not 

 anxious to dispute about their claims. Young's discoveries 

 were very coldly received in England, for very few men un- 

 derstood them ; and unfortunately Lord Brougham wrote 

 some severe articles against them in the * Edinburgh Re- 

 view,' which made people think they were only foolish 

 speculations. But in France two men, Fresnel and his 

 friend M. Arago, understood and valued Young's labours 

 as soon as they heard of them, and from that time the three 



