120 THE UNIVERSE 



device is inexpensive and durable. It is considered 

 a great contribution to wireless telegraphy and 

 establishes it on a commercial basis, and selective 

 signaling is solved and trans-Atlantic transmission 

 will be easy. 



Radium is a rare metal recently discovered, hav- 

 ing remarkable qualities and very difficult to ob- 

 tain. It is a constituent of pitchblende, which is 

 found in many places, but only in a small way. 

 So far all that has been procured has come from 

 a mine in Cornwall. A ton of pitchblende carries 

 about 15^ grains of radium and it is very difficult 

 to extract. A grain is estimated to be worth $200,- 

 000 and a kilogram is worth about $2,000,000. 

 There is only about one pound of radium in the 

 world. It is estimated to be worth $1,000,000. 



Radium was discovered by M. and Mme. Curie, 

 in France, after they had familiarized themselves 

 with the remarkable properties of uranium and 

 polonium. Radium has many curious and inexpli- 

 cable qualities. It continually emits heat and light 

 without combustion, without chemical changes of 

 any kind, and without any change in its bulk, ap- 

 pearance or molecular structure, which remains 

 identical after many months. 



It is so powerful in the energy it constantly hurls 

 forth as to entail many dangers in handling it. 

 Sir Wm. Crookes says in describing it: " Probably 

 if half a kilogram were in a bottle on that table 

 it would kill us all. It would most certainly de- 

 stroy our sight and burn our skins to such an 

 extent we could not survive. The smallest bit placed 

 on one's arm would produce a blister it would 

 take months to heal." It also emits electrons with a 



