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fasten it on to this jar (F)> and let into the vessel that gas 

 which was formed by the action of the voltaic battery upon 

 the water, and which we have produced by changing the 

 water into it; for I may go as far as this, and say we have 

 really, by that experiment, changed the water into that gas. 

 We have not only altered its condition, but we have 

 changed it really and truly into that gaseous substance, and 

 all the water is there which was decomposed by the experi- 

 ment. As I screw this vessel (G H) on here (H), and 

 make the tubes well connected, and when I open the stop- 

 cocks (H H H), if you watch the level of the water 

 (in F), you will see that the gas will rise,, I will now 

 close the stop-cocks, as I have drawn up as much as the 

 vessel can hold t and being safely conveyed into that cham- 

 ber, I will pass into it an electric spark from this Ley- 

 den jar (L)> when the vessel, which is now quite clear 

 and bright, will become dim. There will be no sound, for 

 the vessel is strong enough to confine the explosion. [A 

 spark was then passed through the jar, when the explo- 

 sive mixture was ignited.] Did you see that brilliant 

 light? If I again screw the vessel on to the jar, and 

 open these stop-cocks, you will see that the gas will rise a 

 second time. [The stop-cocks were then opened.] Those 

 gases [referring to the gases first collected in the jar, and 

 which had just been ignited by the electric spark] have dis- 

 appeared, as you see; their place is vacant, and fresh gas 

 has gone in. Water has been formed from them; and if 

 we repeat our operation [repeating the last experiment], I 

 shall have another vacancy, as you will see by the water 

 rising. I always have an empty vessel after the explosion, 

 because the vapor or gas into which that water has been 

 resolved by the battery explodes under the influence of the 

 spark, and changes into water; and by-and-by you will see 

 in this upper vessel some drops of water trickling down the 

 sides and collecting at the bottom. 



We are here dealing with water entirely, without refer- 

 ence to the atmosphere. The water of the candle had the 

 atmosphere helping to produce it ; but in this way it can be 

 produced independently of the air. Water, therefore, ought 

 to contain that other substance which the candle takes from 



