78 Mr. W. Spottiswoode on Stratified Discharges. [May 18, 



tary striae are replaced. If they are replaced in the positions which 

 their predecessors held, the flocculent striae will appear straight in the 

 mirror ; if they are replaced successively nearer the positive terminal, 

 the apparent proper motion will be in the normal direction ; if nearer 

 the negative, it will be reversed. 



Fig. 2. 



An ether-tube examined in the same way showed nearly the same 

 features as the last. The elementary striae were, however, not so easily 

 separable ; and the flocculent striae were formed as usual at an earlier 

 stage near the head of the column than near the foot of it. 



In another carbonic-acid tube the proper motion of the flocculent striae 

 was coincident in direction with that of the elementary ; and the latter 

 were consequently more difficult to disentangle. One point in this tube 

 was particularly noticeable, viz. that as the column of flocculent striae 

 retreated, so did the negative glow advance. The two remained through- 

 out the entire discharge the same distance apart. 



. Fig. 3 represents the discharge in a hydrogen-tube of conical form, 



