under the Influence of the Electric Discharge. 375 



F 



+ 







Narrow. 



Wide. 



Narrow. 



Wide. 







0-23 



019 



0-164 



013 







0-37 



0-89 



018 



012 



4 



0-39 



144 



0-27 



0-16 



8 



0-40 



2-72 



0-40 



0-12 



Whilst during the passage of the negative discharge through 

 the icicle tube only relatively small changes in the heat produced 

 occur with changes in the spark-length, these become very con- 

 siderable (from 0*19 to 2*72) when the positive discharge takes 

 place through the icicle tube. At the same time there were 

 always strong charges on the tube -wall, which led to a 

 fracture of its upper edge at a somewhat high pressure in the 

 tube. Further investigations on the influence of condensation 

 of the electricity on the wall of the tube would probably 

 lead to important conclusions as to the nature of the discharge. 

 I shall return to this further on. 



III. The heating at the electrodes was determined by means 

 of the arrangement of fig. 9, and first when no spark was 

 included. 



In a first series the electrode for which the heating was 

 to be determined was a point connected with the source of 

 electricity. The gas employed was air. 



The amounts of heat were as follows : — 



p 



+ 



- 



P 



4_ 



- 



14-4 



6-2 



2-4 



0-50 

 0-48 

 0-17 



0-74 

 0-39 

 0-34 



12 

 045 



X 



008 

 007 

 006 



0-48 

 0-74 

 1-26 



In a second series the amount of heat was also determined 

 with point electrodes, both when the electrode in question 

 was connected with the machine and also when it was put to 

 earth. The following table contains under a the values 

 obtained in the first case, and under b those obtained in the 

 second case. The water-equivalent of the calorimeter &c. 

 was 6*4. The gas employed was hydrogen : — 



a. 



b. 



P 



+ 



- 



V 



+ 



- 



26-5 



0-63 



0-60 



26 



0-62 



0-50 



8-1 



0-26 



039 



8 



0-24 



030 



2-6 



0-15 



0-37 



2-4 



014 



041 



0-6 



006 



0-64 



0-8 



010 



0-81 



0-2 



007 



0-63 



X 



010 



1-05 



X 



009 



0-77 



— 



— 



— 



