1878.] Discharge in Exhausted Tubes. 375 



then disappeared, to be replaced by others ; the flow, as seen in a 

 rotating mirror, was towards the negative. The phenomena are de- 

 picted in 1, fig. 1. 



Fig. 1. 



Pressure 12'2 millims., 16,053 M, 8>040 cells. The luminosities as 

 in 5, fig. 1. The flow of the luminosities was shown by the rotating 

 mirror to be towards the negative. There was much heat developed 



