@. 
6 J. Trowbridge—Electrical Condition of Gas Flames. 
flame, the instrument showed a positive deflection of 70 to 80 
de 
fix, 4. With ae ee plate 5 mm. from the outer sur- 
face of the flame, on all sides, a feeble positive charge was 
obtained, the air in srhrerten with the flame being apparently 
charged ‘positively, the indication in no case exceeding fifty or 
sixty degrees on the scale of the electrometer. 
Exp. 5. The metallic tip of the burner was found to be 
charged positively, giving an indication closely agreeing in the 
number of degrees with that corresponding to the — in- 
dication of the flame. This indication was quite constant. 
Ex hen a glass tip was substituted for the metallic tip, 
no charge was found upon it. This was the case when any 
non-conducting body formed the tip. 
Exp. lass tip having been substituted for the metallic 
one, a platinum wire was inserted below the orifice and care- 
fully de aaa until it occupied the centre of the in- 
Av 
terior cone of flam very feeble indication of negative 
dautacky Ltn the Nettle 
‘ile, with the Bunsen burner, the flame and the metallic 
tip are in ilecided electrical opposition ; the one having a nega- 
tive charge and the other a nearly equal positive charge; in 
spirit flames the two opposite states recombine, the wick of ‘the 
lamp and the fluid contained in the vessel connecting the two 
charges. The flame, therefore, merely takes the potential of 
the atmospheric electricity at the place where it is situated. 
The electrical condition of the flame of a Bunsen burner 
when tested by a sensitive galvanometer gives in the main the 
same results as those obtained by Prof. Buff from spirit flames. 
The quantity of electricity in the current passing from the flame 
to the tip is exceedingly sm % _— we have seen above 
that the terminal immersed in the gas flame has a tension a 
little exceeding that of the ole pole of a Daniell’s element. 
The air in the room, at the time the above experiments were 
first performed, was charged positively to about the tension of 
the positive pole of twelve Daniell’s elements. The experi- 
ments were afterward repeated when the air in the room indi- 
cated a negative charge, with no difference in the results. 
At the suggestion of Dr. Wolcott Gibbs, Rumford professor, 
m 
means of which I could increase the heat and the flow of air and 
gas at pleasure. Slight deviations in the scale readings were 
Spinal this means: the flow of air appeared to affect the 
wo of ee bsiaes the metallic tip, rendering it less con- 
riments were in the main confirm 
The. ii ae the uallie plate submitted to he flame and 
