NEW CONCEPTIONS IN SCIENCE 



Sir Isaac Newton was among the first to go 

 very deeply into the nature of light ; it was he who 

 first split up the sunbeam into the rainbow-like 

 spectrum, and it was his discoveries in this field 

 that gave him his fame, and made the world listen 

 when, later on, he proposed to reduce the universe 

 to a mathematical equation. Like all great men 

 of science, Newton was endowed with a lively and a 

 very vivid imagination, and it was needful for him, 

 as it was for Franklin and Faraday, to make pict- 

 ures about the matters of his thought. Regard- 

 ing light, as regarding electricity, two conceptions 

 in particular were open. Light might be, like 

 sound in air, merely the rapid vibration of an in- 

 visible and imponderable something; or it might 

 be pictured as an incessant hail of bodies so minute 

 as equally to escape all means of direct investiga- 

 tion. 



Newton reflected deeply, then chose the latter. 

 He called the minute bodies his fancy had created 

 " corpuscles," and in terms of these he built up the 

 Newtonian theory of light. It did not stand very 

 long, and by the time the last century had got 

 fairly on its feet the scientific world had given its 

 suffrage to the rival undulatory theory of Newton's 

 contemporary, Huygens. The latter, in the hands 

 of Young and Fresnel, imagined light simply as a 

 peculiar wave, or wobble -and -wave, in the un- 



136 



