354 



ON THE CONSERVATION OF FORCE. 



bursts into flame, just as happens with oxygen gas, in 

 which the processes of combustion are far more intense 

 than in atmospheric air, where the oxygen mixed with 

 nitrogen is only one-fifth of the whole volume. 



If I hold a glass flask filled with water over the hydro- 

 gen flame, the water, newly formed in combustion, con- 

 denses upon it. 



If a platinum wire be held in the almost non-luminous 

 flame, you see how intensely it is ignited ; in a plentiful 

 current of a mixture of the gases, hydrogen and oxygen, 

 which have been liberated in the above experiment, the 



FIG. 49. 



almost infusible platinum might even be melted. The 

 hydrogen which has here been liberated from the water 

 by the electrical current has regained the capacity of 

 producing large quantities of heat by a fresh combination 

 with oxygen ; its affinity for oxygen has regained for it 

 its capacity for work. 



We here become acquainted with a new source of 

 work, the electric current which decomposes water. This 

 current is itself produced by a galvanic battery, Fig. 49. 



