104 THE NEW KNOWLEDGE. 



science for a time remained content, and, indeed, in error t ; 

 for, as it turned out, Professor Rutherford was finally able to 

 show that, by the application of magnetic forces transcend- 

 ently strong, part of the so-called undeviable beam could, 

 as a matter of fact, be to a slight extent deviated but in the 

 opposite direction from the deviable portion already known, 

 while the other part remained still absolutely undeviable. 

 Furthermore, it turned out that this truly undeviable portion 

 of the beam of rays possessed a penetrative power to an ex- 

 tent simply extraordinary, producing an appreciable effect 

 on a photographic plate through a foot thickness of solid 

 iron! By means of the magnetic effect we have thus been 

 able to analyze the Becquerel rays from radium into three 

 distinct types or kinds of radiation: 



(1) Rays that have very little penetrative power and are 

 only slightly bent by the strongest magnetic forces obtain- 

 able. These are known as the alpha-rays. 



(2) Rays that are very penetrating in character and are 

 easily bent by weak magnetic forces in a direction opposite 

 to that of the alpha-rays. Those rays are known as the 

 beta-rays. 



(3) Rays that are absolutely undeviable by the strongest 

 magnetic force obtainable and have an unexampled power 

 of penetrating matter generally considered opaque. These 

 are the gamma-rays. 



All these three types of rays, it must be remembered are 

 continuously given off by radium compounds in their nat- 

 ural condition without any diminution whatever so far as 

 has yet been detected. We have now all the data nec- 

 essary for answering with a reasonable degree of confidence 

 the question: What are the alpha-, the beta- and the gam- 

 ma-rays from radium? 



