Hydrogen. 193 



active state, and its change of affinity under the 

 temperature which its own combination produees. 

 so as to set free the metals and other substances 

 most useful to man can we Jail to recognise in it 

 the work of an Infinite Intelligence ? 



The second element of the group, hydrogen, is 

 never found as a natural product in an uncombined 

 state. It would be impossible for any considerable 

 quantity of it to exist mingled with the five OXygeH 

 of the atmosphere, without chemically combining 

 under the influence of clcctricitv, and other agen 

 brought to bear upon it. In all the processes of 

 nature, in which hydrogen is liberated by decompo- 

 sition, it is lilu is a compound, or it unites 

 with some other element the instant it is set five. 

 Its most abundant compound, water, is formed by its 

 union with o.\yg n, so that what we shall hereafter 

 say of water will have as much reference to one of 

 these elements as to the other. But hydrogen has 

 of itself properties of paramount importance to 

 man. It is in almost every instance the basis of 

 flame. Any incandescent gas is ilame ; but strike 

 hydrogen from our list of elements, and artificial 

 light from flame would be almost impossible. It is 

 hydrogen that fills our gasometers, and, flowing 

 through the iron arteries beneath the streets 

 throughout the city, shoots forth its jets of flame 

 wherever the wants of man demand it, almost turn- 

 ing night into day. It is hydrogen, that, stored up 

 in the petroleum for countless ages, now flows 

 through the thousand openings in the rocks, and 

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