M. Pouillet 071 the ElectricU?/ of Elastic Fluids. 55 



combined. If the phenomenon takes place in this manner, it 

 is probable that at a certain distance above the flame the two 

 contrary fluids ought no longer to appear, because they will 

 have combined ; and this in fact happens when we try to col- 

 lect the electricity at a distance sufficiently great above the 

 vertical flame; but at the distance of a few inches only, 

 we obtain other effects, — the two electrical fluids appear in 

 the same quantity, but they are not recomposed; for if we 

 present a soldered plate of zinc and copper, the zinc part 

 attracts the resinous, and the copper plate the vitreous electri- 

 city. If, instead of making the hydrogen flow out by a tube 

 of glass, we make it flow out by a tube of metal, which does 

 not communicate with the ground, but only with the conden- 

 ser, we see that this metal tube, which touches the hydrogen 

 without even touching the flame, takes always the resinous elec- 

 tricity ; and if, on the contrary, it is made to communicate with 

 the ground, it loses the resinous electricity which it had lately 

 carried to the condenser, and the product of the combustion 

 preserves an excess of vitreous electricity. 



These experiments upon the combustion of hydrogen and of 

 charcoal made it easy for me to examine other combustible 

 substances, whether they were solids, liquids, or gaseous. It 

 would be tedious, and perhaps useless, to relate the numerous 

 experiments I made upon alcohol, ether, wax, the oils, the fatty 

 substances, and many vegetable bodies. The flames of all 

 these bodies presented exactly the same phenomenon as the 

 flames of hydrogen. 



I remarked only that the particles of charcoal which were 

 floating in the flames of this substance, and which, according 

 to the observations of Sir H. Davy, gives them their shining 

 lustre, makes them also better fitted to show the resinous elec- 

 tricity. From the whole of these experiments, we may deduce 

 the general principle, viz. that in combustion the molecules of 

 oxygen which combine, disengage positive electricity, which 

 can be communicated to the nearest molecules not yet combin- 

 ed, while combustible bodies, on the contrary, disengage nega- 

 tive electricity, which can, in a similar manner, communicate it- 

 self to all the surrounding combustible parts. 



