LATENT HEAT.

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MRS. B.

That is always the case previous to the freezingof water when it is in a state of rest. Now it be-gins to congeal, and you may observe that thethermometer again rises to the freezing point.

CAROLINE.

It appears to me very strange that the thermo-meter should rise the very moment that the waterfreezes; for it seems to imply that the water wascolder before it froze than when in the act offreezing.

MRS. B.

It is so ; and after our long dissertation on thiscircumstance, I did not think that it would appearso surprizing to you. Reflect a little, and I thinkyou will discover the reason of it.

CAROLINE.

It must be, no doubt, the extrication of latentheat, at the instant the water freezes, that raisesthe temperature.

MRS. B.

Certainly; and if you now examine the ther-mometer, you will find that its rise was but tempo-rary, and lasted only during the disengagementof the latent heat; it has since fallen, and willcontinue to fall till the ice and mixture are of anequal temperature.