NEW CONCEPTIONS IN SCIENCE 



phosphorus was contained, he could push his vac- 

 uum as far as the one-twenty-millionth of an at- 

 mosphere. This was a capital advance. 



Armed with his new weapon, Professor Crookes 

 attacked the study of this peculiar glow which Hit- 

 torf had discovered a few years before. One of the 

 first things he came to see was that these radia- 

 tions for under his high vacuum the glow took on 

 more and more the character of a ray of light- 

 always move in perfectly straight lines, and at 

 right angles exactly, to the end of the piece of 

 metal which served to bring the electrical current 

 to one of the ends of the tube. This was always 

 the end of the tube at the opposite side from which 

 the current entered. Faraday named it the cath- 

 ode that is, the negative pole, the pole from which 

 positively electrified particles would be pushed away 

 rather than attracted. Hence grew up the name 

 of cathode rays, as applied to Hittorf s glow, a 

 name which has become so familiar with Professor 

 Rontgen's discovery of the X-rays. 



With this notable observation, that the rays 

 moved in straight lines, it is easy to see that when 

 Professor Crookes took for a cathode a little piece 

 of metal curved like a concave mirror, he could con- 

 centrate the rays in a point. At this point every- 

 thing became tremendously hot. Glass melted. 

 Even the most obstinate of metals, like gold and 



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