CHAP.V. NEW APPLICATIONS OF LIGHT. 41 



trated the knee joint and then broke off, leaving a por- 

 tion embedded which set up inflammation, and might 

 have necessitated the loss of the limb, was shown so accu- 

 rately that a surgeon cut down to it and got it out with- 

 out difficulty. 



An exceptional property of these rays is that they 

 cannot be either refracted or reflected as can -ordinary 

 light and heat. Hence it is only the shadow that can be 

 photographed. And another curious result of this is 

 that they can pass through a powder as easily as through 

 a solid; whereas ordinary light cannot pass through 

 powdered glass or ice, owing to the innumerable reflec- 

 tions and refractions which soon absorb all the rays ex- 

 cept those reflected from a very thin surface layer. 

 Proportionate thicknesses of aluminium or zinc, whether 

 in the solid plate or in powder, are equally transparent to 

 these singular rays. 



So much is already popularly known on this subject 

 that it is not necessary to go into further details here. 

 But this new form of radiant energy opens up so many 

 possibilities, both as to its own nature and as to the 

 illimitable field of research into the properties and 

 powers of the mysterious ether, that it forms a fitting and 

 dramatic climax to the scientific discoveries of the 

 century. 



