the Electricity of Flame. 173 



§ 9. Combination of severed Flames. 



We have still to mention that flames can be combined in 

 exactly the same manner as galvanic cells — the base of one 

 flame being connected with the apex of the second, the base 

 of the second with the apex of the third, and so on. by wires. 

 Three Bnnsen burners, connected in this manner by copper 

 wires, gave the following deflections at the electrometer: — 



1 burner ... 80 scale-divisions. 



2 burners ... 156 „ (160) 



3 .. . . . 245 „ (240) 



"With perfect equality of the burners the numbers in brackets 

 might have been expected. Twenty-five spirit-flames, com- 

 bined in this way into a battery, produced at the electrometer 

 a deflection too small to be measured by mirror and scale. At 

 all events the intensity of the current which set in was, on 

 account of the great resistance within the flames, very little. 

 A sufficiently sensitive multiplier to prove the latter point was 

 not at our disposal. 



§ 10. Summary of the Results. 



1. The longitudinal polarization of flame is only apparent, 

 and is called forth by unequal immersion in the flame of the 

 wires employed as electrodes. 



2. The flame appears to be strongly polarized in its cross 

 section; and the electrode which is in the stratum of air im- 

 mediately enveloping the flame is always positive to the elec- 

 trode in the flame. 



3. In agreement with the points 1 and 2, the electromotive 

 force is independent of the magnitude of the flame. 



4. Change of polarity of the flame can be called forth by a 

 suitable displacement of the electrodes, and likewise finds its 

 explanation in points 1 and 2. 



5. The electromotive force of the flame is dependent on the 

 nature of the metals used as electrodes, and on that of the 

 burning gases. It appears singularly powerfully electric 

 when aluminium or magnesium is made use of as the metal 

 conducting from it; singularly feebly when the electrode in 

 air is covered with a salt (potassium chloride). 



6. Unequivocal electrical effects are likewise obtained from 

 the flame when water electrodes are employed and every metal 

 excluded; and the electrode which is in air is likewise positive 

 to that in the flame. All the above propositions can be con- 

 firmed with liquids, so far as their nature permits. 



7. Flames can be combined after the manner of galvanic 



