4 Stokes, on the Nature of the Rontgen Rays. 



fact, without entering at present into any speculation as 

 to the reason for it, that the Rontgen rays do come out 

 from the glass wall more copiously in a normal direc- 

 tion than in an oblique direction. Assuming this, we 

 can rightly say that the results obtained by Prince 

 Galitzin and M. v. Karnojitzky, and similar results 

 obtained by others, do not by an}' means prove that the 

 seat of the rays is within the tube. Suppose, for 

 example, that the tube were spherical, and a portion of 

 this spherical surface were reached by the cathodic rays; 

 if the Rontgen rays which passed outside came wholly, 

 we will say, in a normal direction, produce the direc- 

 tions backwards and you will get the centre of the tube. 

 But we have no right to say from that there is anything 

 particular going on in the centre of the spherical tube. 

 The result is perfectly compatible with Rontgen's 

 original assertion, which I believe to be true, as to the 

 seat of the rays. 



Everything tends to show that these Rontgen rays 

 are something which, like rays of light, are propagated 

 in the ether. What, then, is the nature of this process 

 going on in the ether ? Some of the properties of the 

 Rontgen rays are very surprising, and very unlike what 

 we are in the habit of considering with regard to rays 

 of light. One of the most striking things is the facility 

 with which they go through bodies which are utterly 



have made the exhaustion higher, and caused the X rays given out to 

 be of higher penetrative power, so as to render the increased thickness 

 of glass which the rays emerging obliquely had to pass through to be 

 of less consequence. But the subject is still under examination. In 

 consequence of the result obtained in the second experiment, the state- 

 ment in the text should be less absolute; but it may very well have 

 happened that in the experiments of others the conditions may more 

 nearly have agreed with those of the first experiment, causing what we 

 may call the resultant activity of the X rays to have had a direction 

 leaning towards the normal drawn from the point casting the shadow 

 to the wall of the tube. 



