CALORIC.

21

EMILY.

To return llien to our subject.—Though I nolonger doubt that light and heat can be separated,Dr. Herschell’s experiment does not appear to meto afford sufficient proof that they are essentiallydifferent; for light, which you call a simple body,may likewise be divided into the various colouredrays; is it not therefore possible that heat mayonly be a modification of light?

MRS. B.

That is a supposition which, in the present stateof natural philosophy, can neither be positivelyaffirmed nor denied: it is generally thought thatlight and heat are connected with each other ascause and effect; but which is the cause, andwhich the effect, it is extremely difficult to deter-mine. It would bo useless, however, to detainyou any longer on this intricate subject; and astlie chemical properties of light can be explainedonly in their reference to compound bodies, letus pass on to the examination of heat, with whichwe are much better acquainted.

CAROLINE.

Heat is not, I believe, among the number ofthe simple bodies ?

MRS. B.

Yes, it is; but under another name—that ofcaloric, by which is meant the principle hr mat-