NEW CONCEPTIONS IN SCIENCE 



of that energy was a mystery. More or less, it is so 

 still, though some tentative explanations have been 

 offered by their discoverer, Sir William Crookes, 

 and others. 



Here was, as it turned out, a wholly new series of 

 natural phenomena. These were just as open to 

 Newton for study as to Professor Becquerel. Why, 

 then, did it require a century and a half of scien- 

 tific development to learn of this new and peculiar 

 property of matter? Newton, we know, experi- 

 mented with almost every substance known to his 

 day, testing each to see if it strictly obeyed his 

 famous law of inverse squares. He seems to have 

 been a good chemist, as chemists went in his day, 

 and was certainly abreast of the science of his time. 

 Why did he not find these radiating bodies? 



One need not voyage far afield for an answer. 

 These new radiations affect none of our primal 

 senses. Though, in following up Becquerel' s discov- 

 ery, M. and Mme. Curie have latterly found other 

 radioactive minerals, like radium, which give off a 

 visible light, those discovered by Becquerel do not. 

 They afford so little appreciable heat that it has only 

 just recently been possible to find a way to detect 

 or measure it ; they arouse no sensations of touch, 

 taste, sound, or smell. How, then, may we become 

 aware that they exist ? Solely by means of our new 

 senses. They impress a photographic plate, one of 



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