In the practical use of the instrument it is not necessary to know both the latent heat of fusion of ice and the change of volume which occurs on melting; it is sufficient to determine the change of volume per calorie, or the quantity of mercury which is drawn into the bulb of the apparatus per unit of heat added.
Though no rise of temperature accompanies the melting of ice, there is yet a definite quantity of heat absorbed, namely, about 80 calories per gram; this is called the latent heat of fusion of water (see FusloN).
Its latent heat of fusion is 11 7 calories, and its latent heat of vaporization is 23.95 calories (P. A.
L, Latent heat of fusion or vaporization.
Its specific gravity is 3.18828 (r), latent heat of fusion 16.185 calories, latent heat of vaporization 45.6 calories, specific heat 0.1071.