314 EXPERIMENTS OF POUILLET. 



which was 2^ or 3 inches below a plate of brass 

 that was connected with the condenser. When 

 the upper part of the charcoal was ignited, a 

 current of carbonic acid arose and came in 

 contact with the brass plate, by which the con- 

 denser was positively electrified in a few mi- 

 nutes. By placing the inferior end of the char- 

 coal on the condenser, and igniting the upper 

 end, the condenser was charged with negative 

 electricity. From these experiments Pouillet 

 concluded, that during the combination of oxy- 

 gen with carbon, it gave out positive electricity, 

 while the carbon gave out negative electricity. 



During some of his experiments, both positive 

 and negative electricity were evolved by the com- 

 bustion of charcoal and hydrogen ; from which 

 it would seem to follow, that positive and nega- 

 tive electricity are only plus and minus condi- 

 tions of the same agent ; although this seems 

 not to have been suspected by Pouillet. The 

 following experiments are among the most in- 

 structive which have been recorded by the French 

 philosopher. He caused hydrogen gas to flow out 

 of a glass tube. When it was ignited, a vertical 

 flame was produced, nearly half an inch in 

 breadth, and three inches in height. A coil of 

 platinum wire was employed to conduct the 

 electricity from the flame to the condenser. 

 When the coil was large enough to inclose the 

 flame, and to be about four inches from its 



