CHAPTER XXVI.
540. What is the difference between light and heat?
The most obvious distinction is, that light acts upon vision, and heat upon sensation, or feeling.
Another distinction is, that heat expands all bodies, and alters their atomic condition; while light, though usually attended by heat, does not display the same expansive force, but produces various effects which are peculiar to itself.
"Ye are the light of the world. A city that is set on a hill cannot be hid."—Matthew v.