MATTER AND FORCE 77 



what now remains. We are truly heirs of all the ages; 

 but as honest men it behooves us to learn the extent of 

 our inheritance, and as brave ones not to whimper if it 

 should prove less than we had supposed. The healthy 

 attitude of mind with reference to this subject is that 

 of the poet, who, when asked whence came the rhodora, 

 joyfully acknowledged his brotherhood with the flower 



"Why thou wert there, rival of the rose I 

 I never thought to ask, I never knew, 

 But- in my simple ignorance supposed 

 The self-same power that brought me there 

 brought you. 1 



A few exceptions to the general state of union of the 

 molecules of the earth's crust vast in relation to us, but 

 trivial in comparison to the total store of which they are 

 the residue still remain. They constitute our main 

 sources of motive power. By far the most important 

 of these are our beds of coal. Distance still intervenes 

 between the atoms of carbon and those of atmospheric 

 oxygen, across which the atoms may be urged by their 

 mutual attractions; and we can utilize the motion thus 

 produced. Once the carbon and the oxygen have rushed 

 together, so as to form carbonic acid, their mutual attrac- 

 tions are satisfied; and, while they continue in this con- 

 dition, as dynamic agents they are dead. Our woods and 

 forests are also sources of mechanical energy, because they 

 have the power of uniting with the atmospheric oxygen. 

 Passing from plants to animals, we find that the source 

 of motive power just referred to is also the source of 



1 Emerson. 



