Machine for producing Higli Tension Electricity. 187 



being a single act of discharge and the arc a multitudinous succes- 

 sion of minutely divided sparks, of which none are sufficiently 

 strong to produce any violent disturbance of the adjacent air. The 

 hissing sound emitted by the arc seems to favour this view. 



I now come to another set of experiments, which will only require 

 a brief notice. They were designed to show the effect of passing 

 both the arc and the spark through an intervening combustion 

 flame. 



Speaking generally, the intervention of flame has much the same 

 effect in increasing the length of the disruptive discharge, whether 

 in the shape of arc or spark, that is effected by rarefaction of air ; 

 but I will here only particularise some curious effects I obtained with 

 the flame of paraffin candles. The annexed series of illustrations 

 exhibit the effects observed in each case. 



Fig.L 



rig. 2. 



Fig. 3 



Fig. 1 shows the positive wire immersed in the flame and the 

 negative wire clear of it, both wires being of platinum and of 22 



