It cannot properly be called ice, since ice implies a degree of cold, at least equal to the freezing point. Yet as water, in combining with lime, gives out more heat than in freezing, it must be in a state of still greater solidity in the lime, than it is in the form of ice; and you may have observed that it does not moisten or liquefy the lime in the smallest degree. EMILY. But, Mrs. B., the smoke that rises is white; if it was only pure caloric which escaped, we might feel, but could not see it. MRS. B. This white vapour is formed by some of the particles of lime, in a state of fine dust, which are carried off by the caloric. EMILY. In all changes of state, then, a body either absorbs or disengages latent heat? MRS. B. You cannot exactly say _absorbs latent heat_, as the heat becomes latent only on being confined in the body; but you may say, generally, that bodies, in passing from a solid to a liquid form, or from the liquid state to that of vapour, absorb heat; and that when the reverse takes place, heat is disengaged.* [Footnote *: This rule, if not universal, admits of very few exceptions.] EMILY. We can now, I think, account for the ether boiling, and the water freezing in vacuo, at the same temperature.† [Footnote †: See page 102.] MRS. B. Let me hear how you explain it. EMILY. The latent heat, which the water gave out in freezing, was immediately absorbed by the ether, during its conversion into vapour; and therefore, from a latent state in one liquid, it passed into a latent state in the other. MRS. B. But this only partly accounts for the result of the experiment; it remains to be explained why the temperature of the ether, while in a state of ebullition, is brought down to the freezing temperature of the water. --It is because the ether, during its evaporation, reduces its own temperature, in the same proportion as that of the water, by converting its free caloric into latent heat: so that, though one liquid boils, and the other freezes, their temperatures remain in a state of equilibrium. EMILY. But why does not water, as well as ether, reduce its own temperature by evaporating? MRS. B.