395 



Fig. 1. 



No. 190 has brass wires, and No. 202 silver wires attached to the 

 platinum : both these tubes are of the same -dimensions as No. 187 

 and 196 (fig. 2). No. 219 is 4 inches long, has gas-coke balls of 



Fig. 2. 



about |th of an inch in diameter, and 1 inch apart : the caustic 

 potash originally attached to this tube has been sealed off; the form 

 is shown in fig. 3. 



Fig. 3. 



1 i 



With the inductive coil the discharge in 146 exhibits a large cloud- 

 like luminosity on the plate, which in these experiments was always 

 made the negative terminal. On the positive wire, minute luminous 

 spots were visible. At intervals, apparently by some sudden energetic 

 action, flashes of bright stratified light would dart through the 

 vacuum, but by carefully adjusting the contact breaker, the discharge 

 could be made to pass, producing a white glow on the negative plate, 

 without to the eye affording any appearance of an intermittent 

 discharge. 



In 187 and 196 the stratifications were narrow from the positive 

 terminal, the negative ball being surrounded with a narrow halo of 

 light similar to that in fig. 1 A, but smaller. In 1 90 there was a red 

 tinge on the cloud-like discharge near the positive terminal ; on the 

 approach of a magnet, two or three additional clouds were brought 

 out, the negative wire being covered with a luminous glow extending 

 to the sides of the tube parallel to the end of the negative wire, 



