308 Royal Society : — 



discharges of equal intensity ; but in no case did any sign of inter- 



4 ' ^^-^^ 



ference appear. The discharges, whether in the same or in opposite 

 directions, mingled ; the stratifications, having a tendency to rotate 

 round the poles of a magnet and obeying the well-known law ot 

 magnetic rotations, could be separated by either pole. 



If, instead of sealed wires, tin-foil coatings, a h (fig. 3), are placed 



a 3 h 



M 



on the vacuum tube, and the coatings are attached to the terminals 

 of the induction-apparatus, brilliant stratifications immediately ap- 

 pear in the portion of the vacuum between the coatings, but without 

 any dark discbarge. On approaching a powerful magnet, the stra- 

 tifications divide into two equal series, in which the bands or strata 

 are concave in opposite directions. 



If a vacuum tube, with or without wires or coatings, is placed on 

 the induction-coil, or on the prime conductor of an electrical machine, 

 stratifications appear which are divided by tlie magnet. Having 

 thus ascertained that there are two distinct forms of the stratified 

 electrical discharge, the author, for the sake of clearness of expres- 

 sion, terms them the direct Jind the induced discharge. The direct 

 discharge is that which is visible in a vacuum when taken from two 

 wires hermetically sealed therein ; this discharge has a tendency to 

 rotate, as a whole, round the poles of a magnet. The induced dis- 

 charge is that which is visible in the same vacuv\m when taken from 

 two metallic coatings attached to the outside of the tube, or from 

 one coating and one wire ; this discharge is divided by the magnet, 

 and the two divisions have a tendency to rotate in opposite direc- 

 tions. The character of these two forms of electrical discharge can 

 always be determined by the magnet. 



The author concludes his paper in the following words : — " I refrain 

 for the present from any observations os to the action of the magnet 

 on the discharge. The intimate relation of magnetic and electric 

 action has long since been shown ; but the curious effect of the 

 power of a magnet to draw out the stratifications from the positive 

 terminal, and in some instances its powerful action on that portion of 

 the discharge which exhibits the phosphorescent light in its great- 

 est intensity, are worthy of further examination. In the preceding 

 experiments my object was directed to the examination of the stra- 

 tified and of the dark band discharge ; at present I am inclined to 

 the opinion that the stratifications in the positive, and the dark band 

 between it and the negative glow, although apparently similar, are 

 effects arising from distinct causes — the former from pulsations or 

 impulses of a force acting in a highly attenuated but resisting 

 medium, the latter from interference. I am at this time engaged in 

 making further experiments for the elucidation of this novel and 

 remarkable phenomenon," 



