TROWBRIDGE. — ELECTRIC DISCHARGES. 643 



the other a rosy red discharge. These discharges are brought to the 

 centre of the disc constituting the end of the anode, instead of being 

 repelled to the edge of the disc, as in the case of the cathode (see 2 

 above). The effect in both 2 and 3 is independent of the name of the 

 pole. 



4. When the cathode light suddenly diminishes, at a definite pressure 

 caused by the sudden introduction of air, ring-shaped striae issue from 

 the anode and travel toward the cathode. 



If a spark gap is introduced in the exterior current circuit, the cathode 

 light diminishes and ring-shaped striae issue from the anode. The 

 energy of projection of the negative particle apparently diminishing 

 quicker than the larger positive particle, the stream of the latter issuing 

 at a greater density from a pointed electrode, can form a luminous ring 

 analogous to vortex rings. 



5. The suppositions that under certain conditions of free path the 

 negative ion is diverted more readily from the line of discharge under 

 the influence of the magnetic field than the positive ion; or, in other 

 words, has a greater energy of movement around the lines of magnetic 

 force than of energy along the line of discharge, and that the reverse 

 holds for the positive ion seemed to be borne out by experiment. 



6. The formations of what I have termed magnetic striae, when the 

 magnetic field is at right angles to the line of discharge, seems to indi- 

 cate that the revolving factor of both negative and positive ions being 

 greater than their energy along the path of discharge, the discharge is 

 hampered, as if in a flow of a liquid an obstacle should be interposed, 

 thus forming ripples. 



7. If we suppose pulsations issuing at different rates from the two 

 terminals of the discharge tube we can by hydrodynamical analogies get 

 an insight into the formation of stratifications. 



8. When the cathode forms the end of a powerful electro-magnet 

 under suitable conditions the output of X-rays is greatly increased. 



9. A new form of discharge is seen in case 8 on the back of the 

 cathode. If these are canal rays, they are formed without a canal. 



10. The fluorescent light on the walls of the X-ray bulb revolve 

 through a comparatively large angle about the pole. 



11. When the anode in an X-ray bulb is also the end of a powerful 

 electro-magnet the application of the magnetic field results in the pro- 

 duction of X-rays from a bulb which cannot be excited without the 

 application of heat. 



1 2. When the anode forms the magnetic pole a violet brush-like light 



