1 86 Natural Theology. 



stitution, either in the simple, or the compound 

 state. 



Three of them are gases so permanent, that no 

 mechanical power that man can bring to bear upon 

 them can reduce them to the solid or liquid form. 

 Oxygen and nitrogen are free, uncombined gases, 

 floating over every inch of the globe, as atmosphere, 

 bathing every object, and under the pressure of their 

 own weight permeating every porous substance. 

 Hydrogen is not found uncombined ; but in its com- 

 pounds, especially in the vapor of water, it is almost, 

 if not quite, as constantly present as the atmo- 

 sphere itself. Carbon, the fourth element, differs 

 entirely from the other three. So far from being a 

 gas, it is one of the most fixed of all bodies ; no 

 heat yet brought to bear upon it having caused it to 

 take the form of vapor. But when united with 

 oxygen it floats away in the air, and as carbonic 

 acid, forms itself an atmosphere for the earth. 



These four elements are, then, ever present in 

 every portion of the earth. No matter how many 

 tons of them are taken up by the green herbage of 

 the field in a single day, at its close there may be 

 just as much of each one of them hovering over it 

 and resting upon it as though not a single grain 

 had been gathered in over its broad acres. These 

 elements mingle together in the whirlwind and the 

 storm. They float together in the gentlest breeze. 

 Every breath of air that fans the cheek, or moves 

 the aspen leaf, bears these four elements as insepa- 

 ble companions. They combine and recombine under 



