under the Influence of the Electric Discharge. 371 





Air. 





Hydrogen. 



p 



+ 



- 



P 



+ 



- 



17-5 



40 



80 



244 



35 



55 



6-2 



75 



90 



8-2 



100 



86 



2-4 



100 



90 



31 



80 



101 



11 



75 



110 



0-8 



90 



350 



03 



40 



180 



X 



55 



170 



X 



60 



140 



XX 



29 



130 



A second series with a somewhat wider capillary tube gave 

 the following amounts of heat : — 



Air. 



Hydrogen. 



P 



F=0 



2^=10 



F=0 



F=10 



P 



4- 

 F=0 F=10 



F=0 



i^=10 



2-4 

 1-42 



0-64 

 0-60 



11 



4-0 

 0-5 



X 



201 

 1-06 

 051 

 025 



1-87 

 1-47 

 101 

 083 



216 

 1-36 

 042 

 037 



2-00 

 1-40 

 097 

 0-73 



12-6 

 4-7 

 0-7 



X 



2-33 

 1-22 

 0-40 

 031 



2-12 

 1-50 

 0-83 

 0-80 



2-50 

 1-20 

 0-43 

 0-27 



The corresponding number of discharges are :- 



Air. 



Hydrogen. 



P 



+ 



- 



P 



+ 



- 



14-0 



66 



33 



13 



80 



90 



59 



83 



60 



51 



90 



90 



2-2 



150 



110 



ri 



90 



120 



0-8 



110 



190 



03 



60 



280 



03 



50 



330 



* 



60 



90 



X 



50 



200 









XX 



30 



90 









Here also the number of discharges was from 12 to 13 

 when a spark 10 millims. long was interposed. 



With reference to the great differences of the number of 

 discharges with and without interposed spark, the following 

 general conclusion may be drawn from the observations : — 



(1) The heating in capillary tubes at pressures above 1 mil- 

 Urn. is almost independent of the quantity of electricity passing 

 in each discharge, and near ly proportional to the ivhole quantity 

 of electricity which passes, always provided that no Leyden 

 jar or condenser is included in the circuit. 



The deviations from this law at pressures under 1 niilim., 

 when the heating increases considerably when a spark is 

 included, require further examination. 



(2) The heating produced by the positive discharge and by 



