572 HENEY A. ROWLAND 



so high the discharge was not oscillatory as in ordinary tubes but only 

 went in one direction. 



In this tube we demonstrated conclusively that the main source of 

 the rays was a minute point on the anode nearest to the cathode. At 

 times a minute point of light appeared at this point, but not always. 



Added to this source the whole of the anode gave out a few rays. 

 From the cathode no rays whatever came, neither were there any from 

 the glass of the tube where the cathode rays struck it as Rontgen 

 thought. This tube as a source of rays far exceeded all our other collec- 

 tion of Crookes' tubes and gave the plate a full exposure at 5 or 10 cm. 

 in about 5 or 10 minutes with a slow-acting coil giving only about 4 

 sparks per second. 



The next most satisfactory tube had aluminium poles with ends about 

 3 cm. apart. It was not straight, but had three bulbs, the poles being in 

 the end bulbs and the passage between them being rather wide. In this 

 case the discharge was slightly oscillatory, but more electricity went one 

 way than the other. Here the source of rays was two points in the tube, 

 a little on the cathode side of the narrow parts. 



In the other tubes there seemed to be diffuse sources, probably due 

 in part to the oscillatory discharge, but in no case did the cathode rays 

 seem to have anything to do with the Rontgen rays. Judging from the 

 first two most definite tubes the source of the rays seems to be more 

 connected with the anode than the cathode, and in both of the tubes the 

 rays came from where the discharge from the anode expanded itself to- 

 ward the cathode, if we may roughly use such language. 



As to what these rays are it is too early to even guess. That they and 

 the cathode rays are destined to give us a far deeper insight into nature 

 nobody can doubt. 



Baltimore, Feb. 20, 1896. 



