EFFECTS OF HEAT AND LIGHT. 57 



GEiPOERAL STATEMENTS. 



From the foregoing it is apparent that the effects of chemical energy, 

 gravity, and heat and light are not independent of one another; on the 

 contrary, they are most intricately interlocked. To a considerable degree 

 any one of the forms of energy may be transformed into the others. Con- 

 sequently the action of one almost always produces an effect upon the 

 action of the others. Moreover, one almost never, acts without the action 

 of the others. Frequently all of the forces of metamorphism are important 

 simultaneous factors in the results; again, one or two of the forces may be 

 prominent, or even dominant, the others playing a subordinate part. But, 

 in every transformation of metamorphism, if all the energy factors of the 

 entire system affected be taken into account, some of the energy is changed 

 into the lowest form of energy, heat, and at least a portion of this heat is 

 dissipated." 



"Darnell, Alfred, A text-book of the principles of physics, 3d ed., Macmillan Co., New York, 

 1895, p. 51. 



