M. B. W. Feddersen on- the Electric Spark. 509 



In general these results support the hypothesis advanced by 

 Ricss : it is only on comparing those intervals of time where a 

 resistance is introduced either on one side or symmetrically with 

 respect to the spark-micrometer, that we meet with something 

 remarkable. Of the observations, for instance, marked with an 

 asterisk, a friend to whom I showed the experiment, and who did 

 not know the resistance employed, was of opinion that the great- 

 est interval occurred in the last observation. If, now, we consider 

 these two observations as conclusive, we may come to the con- 

 clusion that the phsenomenou of discharge is not altered on bring- 

 ing on to one of the coatings any resistance smaller than that 

 already existing on the other one. This may undoubtedly be 

 made to agree very well with a theoretical explanation of the 

 intermittent discharge. I must not, however, conceal the fact, 

 that in other cases, after the introduction of the second resist- 

 ance, an increase in the interval of time was produced ; never- 

 theless such increase was never so great as that which would 

 have been obtained by adding the intervals of time due to the 

 two resistances acting independently and alone. 



Duration of the total discharge.— 'Qdorc I was acquainted with 

 the regular series of the partial discharges, I had endeavoured, 



t Some days previously, shortly after the first filling, I hud found for 

 + ric the interval 2i millims. to 6 millims., iind thence the smallest inter- 

 val of time, 0-O00;j()f) second. Any i)lia;nomenon of i)oliii-i-/.ation would ui 

 time have c.-^erted an opposite influeiu-e. There was, moreover, scarcely a 

 trace of any separation of the two constituents of the water noticeable. 



