[CONVERSATION II.]
ON LIGHT AND HEAT OR CALORIC.
CAROLINE.
We have learned by heart the names of all the simple bodies which you have enumerated, and we are now ready to enter on the examination of each of them successively. You will begin, I suppose, with LIGHT?
MRS. B.
Respecting the nature of light we have little more than conjectures. It is considered by most philosophers as a real substance, immediately emanating from the sun, and from all luminous bodies, from which it is projected in right lines with prodigious velocity. Light, however, being imponderable, it cannot be confined and examined by itself; and therefore it is to the effects it produces on other bodies, rather than to its immediate nature, that we must direct our attention.
The connection between light and heat is very obvious; indeed, it is such, that it is extremely difficult to examine the one independently of the other.
EMILY.
But, is it possible to separate light from heat; I thought they were only different degrees of the same thing, fire?
MRS. B.